This is gnuplot.info, produced by makeinfo version 4.13 from
./gnuplot.texi.

INFO-DIR-SECTION Math
START-INFO-DIR-ENTRY
* GNUPLOT: (gnuplot).             An Interactive Plotting Program
END-INFO-DIR-ENTRY


File: gnuplot.info,  Node: Top,  Next: gnuplot,  Prev: (dir),  Up: (dir)

Master Menu
***********

                            GNUPLOT

                 An Interactive Plotting Program
                  Thomas Williams & Colin Kelley
                     Version 4.6 organized by:
         Hans-Bernhard Broeker, Ethan A Merritt, and others

        Copyright (C) 1986 - 1993, 1998, 2004   Thomas Williams, Colin Kelley
                Copyright (C) 2004 - 2011  various authors

            Mailing list for comments: gnuplot-info@lists.sourceforge.net
          Mailing list for bug reports: gnuplot-bugs@lists.sourceforge.net

              This manual was originally prepared by Dick Crawford
                        Version 4.6 - December 2011


     Major contributors (alphabetic order):

* Menu:

* gnuplot::
* plotting_styles::
* Commands::
* Terminal_types::
* Bugs::
* Concept_Index::
* Command_Index::
* Options_Index::
* Function_Index::
* Terminal_Index::


File: gnuplot.info,  Node: gnuplot,  Next: plotting_styles,  Prev: Top,  Up: Top

1 gnuplot
*********

* Menu:

* Copyright::
* Introduction::
* Seeking-assistance::
* New_features::
* Backwards_compatibility::
* Batch/Interactive_Operation::
* Canvas_size::
* Command-line-editing::
* Comments::
* Coordinates::
* Datastrings::
* Enhanced_text_mode::
* Environment::
* Expressions::
* Fonts::
* Glossary::
* linetypes::
* mouse_input::
* Plotting::
* Start-up_(initialization)::
* String_constants_and_string_variables::
* Substitution_and_Command_line_macros::
* Syntax::
* Time/Date_data::


File: gnuplot.info,  Node: Copyright,  Next: Introduction,  Prev: gnuplot,  Up: gnuplot

1.1 Copyright
=============

         Copyright (C) 1986 - 1993, 1998, 2004, 2007  Thomas Williams, Colin Kelley

   Permission to use, copy, and distribute this software and its
documentation for any purpose with or without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation.

   Permission to modify the software is granted, but not the right to
distribute the complete modified source code.  Modifications are to be
distributed as patches to the released version.  Permission to
distribute binaries produced by compiling modified sources is granted,
provided you
       1. distribute the corresponding source modifications from the
        released version in the form of a patch file along with the binaries,
       2. add special version identification to distinguish your version
        in addition to the base release version number,
       3. provide your name and address as the primary contact for the
        support of your modified version, and
       4. retain our contact information in regard to use of the base
        software.

   Permission to distribute the released version of the source code
along with corresponding source modifications in the form of a patch
file is granted with same provisions 2 through 4 for binary
distributions.

   This software is provided "as is" without express or implied warranty
to the extent permitted by applicable law.

           AUTHORS

           Original Software:
              Thomas Williams,  Colin Kelley.

           Gnuplot 2.0 additions:
              Russell Lang, Dave Kotz, John Campbell.

           Gnuplot 3.0 additions:
              Gershon Elber and many others.

           Gnuplot 4.0 additions:
              See list of contributors at head of this document.


File: gnuplot.info,  Node: Introduction,  Next: Seeking-assistance,  Prev: Copyright,  Up: gnuplot

1.2 Introduction
================

`Gnuplot` is a portable command-line driven graphing utility for Linux,
OS/2, MS Windows, OSX, VMS, and many other platforms. The source code
is copyrighted but freely distributed (i.e., you don't have to pay for
it). It was originally created to allow scientists and students to
visualize mathematical functions and data interactively, but has grown
to support many non-interactive uses such as web scripting. It is also
used as a plotting engine by third-party applications like Octave.
Gnuplot has been supported and under active development since 1986.

   Gnuplot supports many types of plots in either 2D and 3D. It can
draw using lines, points, boxes, contours, vector fields, surfaces, and
various associated text. It also supports various specialized plot
types.

   Gnuplot supports many different types of output: interactive screen
terminals (with mouse and hotkey input), direct output to pen plotters
or modern printers, and output to many file formats (eps, emf, fig,
jpeg, LaTeX, pdf, png, postscript, ...). Gnuplot is easily extensible
to include new output modes.  Recent additions include interactive
terminals based on wxWidgets (usable on multiple platforms), and Qt.
Mouseable plots embedded in web pages can be generated using the svg or
HTML5 canvas terminal drivers.

   The command language of `gnuplot` is case sensitive, i.e. commands
and function names written in lowercase are not the same as those
written in capitals. All command names may be abbreviated as long as
the abbreviation is not ambiguous. Any number of commands may appear on
a line, separated by semicolons (;). Strings may be set off by either
single or double quotes, although there are some subtle differences.
See `syntax` and `quotes` for more details. Examples:

           load "filename"
           cd 'dir'

   Commands may extend over several input lines by ending each line but
the last with a backslash (\).  The backslash must be the _last_
character on each line.  The effect is as if the backslash and newline
were not there.  That is, no white space is implied, nor is a comment
terminated.  Therefore, commenting out a continued line comments out
the entire command (see `comments`).  But note that if an error occurs
somewhere on a multi-line command, the parser may not be able to locate
precisely where the error is and in that case will not necessarily
point to the correct line.

   In this document, curly braces ({}) denote optional arguments and a
vertical bar (|) separates mutually exclusive choices.  `Gnuplot`
keywords or *note help:: topics are indicated by backquotes or
`boldface` (where available).  Angle brackets (<>) are used to mark
replaceable tokens.  In many cases, a default value of the token will
be taken for optional arguments if the token is omitted, but these
cases are not always denoted with braces around the angle brackets.

   For built-in help on any topic, type *note help:: followed by the
name of the topic or `help ?` to get a menu of available topics.

   The new `gnuplot` user should begin by reading about `plotting` (if
in an interactive session, type `help plotting`).

   See the simple.dem demo, also available together with other demos on
the web page http://www.gnuplot.info/demo/
(http://www.gnuplot.info/demo/) `Gnuplot` can be started from a command
line or from an icon according to the desktop environment. Running it
from command line can take the syntax
           gnuplot {OPTIONS} file1 file2 ...

   where file1, file2, etc. are input file as in the `load` command.
On X11-based systems, you can use
           gnuplot {X11OPTIONS} {OPTIONS} file1 file2 ...

   see your X11 documentation and `x11` in this document.

   Options interpreted by gnuplot may come anywhere on the line.  Files
are executed in the order specified, as are commands supplied by the -e
option, for example
           gnuplot   file1.in   -e "reset"   file2.in

   The special filename "-" is used to force reading from stdin.
`Gnuplot` exits after the last file is processed.  If no load files are
named, `Gnuplot` takes interactive input from stdin.  See help
`batch/interactive` for more details.  The options specific to gnuplot
can be listed by typing
           gnuplot --help

   See `command line options` for more details.

   In sessions with an interactive plot window you can hit 'h' anywhere
on the plot for help about `hotkeys` and `mousing` features.  Section
`seeking-assistance` will help you to find further information, help
and FAQ.


File: gnuplot.info,  Node: Seeking-assistance,  Next: New_features,  Prev: Introduction,  Up: gnuplot

1.3 Seeking-assistance
======================

The canonical gnuplot web page can be found at http://www.gnuplot.info
(http://www.gnuplot.info)

   Before seeking help, please check file FAQ.pdf or the above website
for FAQ (Frequently Asked Questions) list.
(http://www.gnuplot.info/faq/)

   If you need help as a gnuplot user, please use the newsgroup
               comp.graphics.apps.gnuplot

   We prefer that you read the messages through the newsgroup rather
than subscribing to the mailing list which is also available and
carries the same set of messages. Instructions for subscribing to
gnuplot mailing lists may be found via the gnuplot development website
on SourceForge http://sourceforge.net/projects/gnuplot
(http://sourceforge.net/projects/gnuplot)

   The address for mailing to list members is:
               gnuplot-info@lists.sourceforge.net

   Bug reports and code contributions should be uploaded to the
trackers at
               http://sourceforge.net/projects/gnuplot/support

   Please check previous bug reports if the bug you want to report has
not been already fixed in a newer version of gnuplot.

   A mailing list for those interested in development version of
gnuplot is:
               gnuplot-beta@lists.sourceforge.net

   When posting a question, please include full details of the gnuplot
version, the terminal type, and the operating system you are using.  A
_small_ script demonstrating the problem may be useful.  Function plots
are preferable to datafile plots.


File: gnuplot.info,  Node: New_features,  Next: Backwards_compatibility,  Prev: Seeking-assistance,  Up: gnuplot

1.4 New features
================

This section lists major additions since version 4.4.  For a more
exhaustive list, see the NEWS file.

* Menu:

* New_syntax::
* Local_customization_of_linetypes::
* New_plot_styles::
* Revised_polar_axes::
* New_smoothing_algorithms::
* New_time/date_handling::
* Statistical_summary_of_data::
* New_or_revised_terminal_drivers::


File: gnuplot.info,  Node: New_syntax,  Next: Local_customization_of_linetypes,  Prev: New_features,  Up: New_features

1.4.1 New syntax
----------------

This version of gnuplot introduces command iteration and
block-structured if/else/while/do constructs.  See `if`, `while`, and
`do`.  Simple iteration is possible inside `plot` or `set` commands.
See *note iteration::.  General iteration spanning multiple commands is
possible using a block construct as shown below.  For a related new
feature, see the `summation` expression type.  Here is an example using
several of these new syntax features:
           set multiplot layout 2,2
           fourier(k, x) = sin(3./2*k)/k * 2./3*cos(k*x)
           do for [power = 0:3] {
               TERMS = 10**power
               set title sprintf("%g term Fourier series",TERMS)
               plot 0.5 + sum [k=1:TERMS] fourier(k,x) notitle
           }
           unset multiplot

   It is now possible to select a column of data from a data file by
matching a label in the first row of the file. See *note columnhead::.
For example
           plot for [crop in "Oats Peas Beans"] 'data' using "Year":crop


File: gnuplot.info,  Node: Local_customization_of_linetypes,  Next: New_plot_styles,  Prev: New_syntax,  Up: New_features

1.4.2 Local customization of linetypes
--------------------------------------

You can now customize properties (color, linewidth, point type) of the
default sequence of linetypes used in plotting. See `set linetype`.
This is normally done in an initialization file, either the system-wide
file `gnuplotrc` or a private file `~/.gnuplot`. See `initialization`.

   Most terminals now allow you to set an explicit background color for
the plot.  The special linetype `bgnd` can be used to draw in this
color. See `bgnd`.


File: gnuplot.info,  Node: New_plot_styles,  Next: Revised_polar_axes,  Prev: Local_customization_of_linetypes,  Up: New_features

1.4.3 New plot styles
---------------------

See documentation for plot styles *note boxplot::, *note circles::,
*note ellipses::, and *note fillsteps::.


File: gnuplot.info,  Node: Revised_polar_axes,  Next: New_smoothing_algorithms,  Prev: New_plot_styles,  Up: New_features

1.4.4 Revised polar axes
------------------------

Polar plot mode has been reworked to support additional plot styles.
The polar axes can now be drawn and labeled independent of the x and y
axes. See `set polar` and *note rrange::.


File: gnuplot.info,  Node: New_smoothing_algorithms,  Next: New_time/date_handling,  Prev: Revised_polar_axes,  Up: New_features

1.4.5 New smoothing algorithms
------------------------------

New smoothing algorithms have been added for both 2- and 3-dimensional
plots.  `smooth kdensity` and `smooth cumulative` can be used with
`plot` to draw smooth histograms and cumulative distribution functions.
Several new smoothing kernels have been added to *note dgrid3d:: for
use with `splot`.  See *note smooth:: *note dgrid3d::.


File: gnuplot.info,  Node: New_time/date_handling,  Next: Statistical_summary_of_data,  Prev: New_smoothing_algorithms,  Up: New_features

1.4.6 New time/date handling
----------------------------

Gnuplot now tracks time to millisecond precision. Time formats have been
modified to match this. The new built-in function time() returns the
current time of day according to the system clock.  Example: print the
current time to msec precision
          print strftime("%H:%M:%.3S %d-%b-%Y",time(0.0))
          18:15:04.253 16-Apr-2011


File: gnuplot.info,  Node: Statistical_summary_of_data,  Next: New_or_revised_terminal_drivers,  Prev: New_time/date_handling,  Up: New_features

1.4.7 Statistical summary of data
---------------------------------

The new `stats` command reads data from a file using the same syntax as
the `plot` or `splot` commands. Rather than drawing a graph, it prints
out a statistical summary of the data contained in the column[s]
requested.  The resulting statistics  min, max, mean, standard
deviation, correlation, etc. are also stored in named variables that
can be used to compose or modify subsequent plotting commands.  See
`stats`.


File: gnuplot.info,  Node: New_or_revised_terminal_drivers,  Prev: Statistical_summary_of_data,  Up: New_features

1.4.8 New or revised terminal drivers
-------------------------------------

The `qt` driver implements an interactive terminal on top of the Qt
graphics layer.  It can function either as a window in a full-featured
desktop enviroment or as a full-screen application on a Qt-based
embedded device.  The `qt` terminal is new and may still have some
rough edges.

   Two terminal types support web-based interactive display. The HTML5
`canvas` terminal was introduced in version 4.4. The `svg` terminal has
been extensively revised to include support for mousing and better
incorporation of svg plots from gnuplot into larger svg/xml documents.

   The `canvas` terminal driver produces javascript output that draws
onto the HTML canvas element of a web page.  It can produce either a
complete web page containing a single plot, or a script that can be
embedded as part of an externally generated HTML document that perhaps
contains multiple plots.  The embedded plots support browser-side
mousing, including zoom/unzoom.

   The `lua` terminal driver creates data intended to be further
processed by a script in the lua programming language.  At this point
only one such lua script, gnuplot-tikz.lua, is available.  It produces
a TeX document suitable for use with the latex TikZ package.  Other lua
scripts could be written to process the gnuplot output for use with
other TeX packages, or with other non-TeX tools.

   `set term tikz` is shorthand for `set term lua tikz`.  As decribed
above, it uses the generic lua terminal and an external lua script to
produce a latex document.

   The `context` terminal driver creates output to be further processed
by the ConTeXt TeX macro package. To process its output, you
additionally require the gnuplot module for ConTeXt available at
http://ctan.org/pkg/context-gnuplot
(http://ctan.org/pkg/context-gnuplot)

   The `epscairo` terminal uses the cairo and pango libraries to create
encapsulated postscript (eps) ouput. It is an alternative to the
`postscript` terminal driver for those who would like to have their eps
files look equal to e.g. screen output by the `wxt` terminal.

   The `cairolatex` terminal uses the cairo backend of the `pdfcairo` or
`epscairo` terminal to produce graphs for inclusion in LaTeX documents.
It creates pdf or eps graphics but transfers texts to LaTeX in the same
way as the `epslatex` terminal.

   The `windows` terminal driver has been revised to suport
transparency, antialiasing, buffered output, multiple graph windows and
copying to clipboard and saving of graphs as emf files. It has many new
options and a revised user interface. Additionaly, the code of the text
console has been largely rewritten to support wrapping of long lines.
Help is now provided via HTML.


File: gnuplot.info,  Node: Backwards_compatibility,  Next: Batch/Interactive_Operation,  Prev: New_features,  Up: gnuplot

1.5 Backwards compatibility
===========================

Gnuplot version 4.0 deprecated certain syntax used in earlier versions,
but continued to recognize it.  This is now under the control of a
configuration option, and can be enabled as follows:

           ./configure --enable-backwards-compatibility

   Notice: Deprecated syntax items may be removed entirely in some
future version of gnuplot.

   One major difference is the introduction of keywords to disambiguate
complex commands, particularly commands containing string variables. A
notable issue was the use of bare numbers to specify offsets, line and
point types.  Illustrative examples:

   Deprecated:
           set title "Old" 0,-1
           set data linespoints
           plot 1 2 4               # horizontal line at y=1

   New:
           TITLE = "New"
           set title TITLE offset char 0, char -1
           set style data linespoints
           plot 1 linetype 2 pointtype 4


File: gnuplot.info,  Node: Batch/Interactive_Operation,  Next: Canvas_size,  Prev: Backwards_compatibility,  Up: gnuplot

1.6 Batch/Interactive Operation
===============================

`Gnuplot` may be executed in either batch or interactive modes, and the
two may even be mixed together on many systems.

   Any command-line arguments are assumed to be either program options
(first character is -) or names of files containing `gnuplot` commands.
The option -e "command" may be used to force execution of a gnuplot
command. Each file or command string will be executed in the order
specified.  The special filename "-" is indicates that commands are to
be read from stdin.  `Gnuplot` exits after the last file is processed.
If no load files and no command strings are specified, `gnuplot`
accepts interactive input from stdin.

   Both the *note exit:: and *note quit:: commands terminate the
current command file and `load` the next one, until all have been
processed.

   Examples:

   To launch an interactive session:
           gnuplot

   To launch a batch session using two command files "input1" and
"input2":
           gnuplot input1 input2

   To launch an interactive session after an initialization file
"header" and followed by another command file "trailer":
           gnuplot header - trailer

   To give `gnuplot` commands directly in the command line, using the
"-persist" option so that the plot remains on the screen afterwards:
           gnuplot -persist -e "set title 'Sine curve'; plot sin(x)"

   To set user-defined variables a and s prior to executing commands
from a file:
           gnuplot -e "a=2; s='file.png'" input.gpl


File: gnuplot.info,  Node: Canvas_size,  Next: Command-line-editing,  Prev: Batch/Interactive_Operation,  Up: gnuplot

1.7 Canvas size
===============

In earlier versions of gnuplot, some terminal types used the values from
*note size:: to control also the size of the output canvas; others did
not.  The use of 'set size' for this purpose was deprecated in version
4.2.  Since version 4.4 almost all terminals now behave as follows:

   `set term <terminal_type> size <XX>, <YY>` controls the size of the
output file, or "canvas". Please see individual terminal documentation
for allowed values of the size parameters.  By default, the plot will
fill this canvas.

   `set size <XX>, <YY>` scales the plot itself relative to the size of
the canvas.  Scale values less than 1 will cause the plot to not fill
the entire canvas.  Scale values larger than 1 will cause only a
portion of the plot to fit on the canvas.  Please be aware that setting
scale values larger than 1 may cause problems on some terminal types.

   The major exception to this convention is the PostScript driver,
which by default continues to act as it has in earlier versions. Be
warned that the next version of gnuplot may change the default
behaviour of the PostScript driver as well.

   Example:

           set size 0.5, 0.5
           set term png size 600, 400
           set output "figure.png"
           plot "data" with lines

   These commands will produce an output file "figure.png" that is 600
pixels wide and 400 pixels tall. The plot will fill the lower left
quarter of this canvas.  This is consistent with the way multiplot mode
has always worked.


File: gnuplot.info,  Node: Command-line-editing,  Next: Comments,  Prev: Canvas_size,  Up: gnuplot

1.8 Command-line-editing
========================

Command-line editing and command history are supported using either an
external gnu readline library, an external BSD libedit library,  or a
built-in equivalent.  This choice is a configuration option at the time
gnuplot is built.

   The editing commands of the built-in version are given below. Please
note that the action of the DEL key is system-dependent. The gnu
readline and BSD libedit libraries have their own documentation.

           `Line-editing`:

           ^B    moves back a single character.
           ^F    moves forward a single character.
           ^A    moves to the beginning of the line.
           ^E    moves to the end of the line.
           ^H    deletes the previous character.
           DEL   deletes the current character.
           ^D    deletes current character, sends EOF if the line is empty.
           ^K    deletes from current position to the end of line.
           ^L,^R redraws line in case it gets trashed.
           ^U    deletes the entire line.
           ^W    deletes previous word.

           `History`:

           ^P    moves back through history.
           ^N    moves forward through history.


File: gnuplot.info,  Node: Comments,  Next: Coordinates,  Prev: Command-line-editing,  Up: gnuplot

1.9 Comments
============

Comments are supported as follows: a `#` may appear in most places in a
line and `gnuplot` will ignore the rest of the line.  It will not have
this effect inside quotes, inside numbers (including complex numbers),
inside command substitutions, etc.  In short, it works anywhere it
makes sense to work.

   See also `set datafile commentschars` for specifying comment
characters in data files.  Note that if a comment line ends in '\' then
the subsequent line is also treated as a comment.


File: gnuplot.info,  Node: Coordinates,  Next: Datastrings,  Prev: Comments,  Up: gnuplot

1.10 Coordinates
================

The commands *note arrow::, `set key`, `set label` and *note object::
allow you to draw something at an arbitrary position on the graph.
This position is specified by the syntax:

           {<system>} <x>, {<system>} <y> {,{<system>} <z>}

   Each <system> can either be `first`, `second`, `graph`, `screen`, or
`character`.

   `first` places the x, y, or z coordinate in the system defined by
the left and bottom axes; `second` places it in the system defined by
the second axes (top and right); `graph` specifies the area within the
axes--0,0 is bottom left and 1,1 is top right (for splot, 0,0,0 is
bottom left of plotting area; use negative z to get to the base--see
*note xyplane::); `screen` specifies the screen area (the entire
area--not just the portion selected by *note size::), with 0,0 at
bottom left and 1,1 at top right; and `character` gives the position in
character widths and heights from the bottom left of the screen area
(screen 0,0), `character` coordinates depend on the chosen font size.

   If the coordinate system for x is not specified, `first` is used.
If the system for y is not specified, the one used for x is adopted.

   In some cases, the given coordinate is not an absolute position but a
relative value (e.g., the second position in *note arrow:: ... `rto`).
In most cases, the given value serves as difference to the first
position.  If the given coordinate resides in a logarithmic axis the
value is interpreted as factor. For example,

           set logscale x
           set arrow 100,5 rto 10,2

   plots an arrow from position 100,5 to position 1000,7 since the x
axis is logarithmic while the y axis is linear.

   If one (or more) axis is timeseries, the appropriate coordinate
should be given as a quoted time string according to the *note
timefmt:: format string.  See *note xdata:: and *note timefmt::.
`Gnuplot` will also accept an integer expression, which will be
interpreted as seconds from 1 January 2000.


File: gnuplot.info,  Node: Datastrings,  Next: Enhanced_text_mode,  Prev: Coordinates,  Up: gnuplot

1.11 Datastrings
================

Data files may contain string data consisting of either an arbitrary
string of printable characters containing no whitespace or an arbitrary
string of characters, possibly including whitespace, delimited by
double quotes.  The following sample line from a datafile is
interpreted to contain four columns, with a text field in column 3:

       1.000 2.000 "Third column is all of this text" 4.00

   Text fields can be positioned within a 2-D or 3-D plot using the
commands:

       plot 'datafile' using 1:2:4 with labels
       splot 'datafile' using 1:2:3:4 with labels

   A column of text data can also be used to label the ticmarks along
one or more of the plot axes. The example below plots a line through a
series of points with (X,Y) coordinates taken from columns 3 and 4 of
the input datafile.  However, rather than generating regularly spaced
tics along the x axis labeled numerically, gnuplot will position a tic
mark along the x axis at the X coordinate of each point and label the
tic mark with text taken from column 1 of the input datafile.

       set xtics
       plot 'datafile' using 3:4:xticlabels(1) with linespoints

   There is also an option that will interpret the first entry in a
column of input data (i.e. the column heading) as a text field, and use
it as the key title for data plotted from that column. The example
given below will use the first entry in column 2 to generate a title in
the key box, while processing the remainder of columns 2 and 4 to draw
the required line:

       plot 'datafile' using 1:(f($2)/$4) with lines title columnhead(2)

   Another example:

       plot for [i=2:6] 'datafile' using i title "Results for ".columnhead(i)

   See *note labels::, `using xticlabels`, *note title::, *note using::.


File: gnuplot.info,  Node: Enhanced_text_mode,  Next: Environment,  Prev: Datastrings,  Up: gnuplot

1.12 Enhanced text mode
=======================

Many terminal types support an enhanced text mode in which additional
formatting information is embedded in the text string.  For example,
"x^2" will write x-squared as we are used to seeing it, with a
superscript 2.  This mode is normally selected when you set the
terminal, e.g.  "set term png enhanced", but may also be toggled
afterward using "set termoption enhanced", or by marking individual
strings as in "set label 'x_2' noenhanced".

      Control      Examples        Explanation
       ^           a^x             superscript
       _           a_x             subscript
       @           @x or a@^b_{cd} phantom box (occupies no width)
       &           &{space}        inserts space of specified length
       ~           ~a{.8-}         overprints '-' on 'a', raised by .8
                                   times the current fontsize

   Braces can be used to place multiple-character text where a single
character is expected (e.g., 2^{10}).  To change the font and/or size,
use the full form: {/[fontname][=fontsize | *fontscale] text}.  Thus
{/Symbol=20 G} is a 20 pt GAMMA and {/*0.75 K} is a K at three-quarters
of whatever fontsize is currently in effect.  (The '/' character MUST
be the first character after the '{'.)

   The phantom box is useful for a@^b_c to align superscripts and
subscripts but does not work well for overwriting an accent on a
letter.  For the latter, it is much better to use an encoding  (e.g.
iso_8859_1 or utf8) that contains a large variety of letters with
accents or other diacritical marks.  See *note encoding::. Since the
box is non-spacing, it is sensible to put the shorter of the subscript
or superscript in the box (that is, after the @).

   Space equal in length to a string can be inserted using the '&'
character.  Thus
             'abc&{def}ghi'

   would produce
             'abc   ghi'.

   The '~' character causes the next character or bracketed text to be
overprinted by the following character or bracketed text.  The second
text will be horizontally centered on the first.  Thus '~a/' will
result in an 'a' with a slash through it.  You can also shift the
second text vertically by preceding the second text with a number,
which will define the fraction of the current fontsize by which the
text will be raised or lowered.  In this case the number and text must
be enclosed in brackets because more than one character is necessary.
If the overprinted text begins with a number, put a space between the
vertical offset and the text ('~{abc}{.5 000}'); otherwise no space is
needed ('~{abc}{.5--}').  You can change the font for one or both
strings ('~a{.5 /*.2 o}'--an 'a' with a one-fifth-size 'o' on top--and
the space between the number and the slash is necessary), but you can't
change it after the beginning of the string.  Neither can you use any
other special syntax within either string.  You can, of course, use
control characters by escaping them (see below), such as '~a{\^}'

   You can access special symbols numerically by specifying
\character-code (in octal), e.g., {/Symbol \245} is the symbol for
infinity. This does not work for multibyte encodings like UTF-8,
however.  In a UTF-8 environment, you should be able to enter multibyte
sequences implicitly by typing or otherwise selecting the character you
want.

   You can escape control characters using \, e.g.,  \\, \{, and so on.

   But be aware that strings in double-quotes are parsed differently
than those enclosed in single-quotes.  The major difference is that
backslashes may need to be doubled when in double-quoted strings.

   Examples (these are hard to describe in words--try them!):
           set xlabel 'Time (10^6 {/Symbol m}s)'
           set title '{/Symbol=18 \\362@_{/=9.6 0}^{/=12 x}} \\
                      {/Helvetica e^{-{/Symbol m}^2/2} d}{/Symbol m}'

   The file "ps_guide.ps" in the /docs/psdoc subdirectory of the
gnuplot source distribution contains more examples of the enhanced
syntax.


File: gnuplot.info,  Node: Environment,  Next: Expressions,  Prev: Enhanced_text_mode,  Up: gnuplot

1.13 Environment
================

A number of shell environment variables are understood by `gnuplot`.
None of these are required, but may be useful.

   If GNUTERM is defined, it is used as the name of the terminal type
to be used.  This overrides any terminal type sensed by `gnuplot` on
start-up, but is itself overridden by the .gnuplot (or equivalent)
start-up file (see `startup`) and, of course, by later explicit changes.

   GNUHELP may be defined to be the pathname of the HELP file
(gnuplot.gih).

   On VMS, the logical name GNUPLOT$HELP should be defined as the name
of the help library for `gnuplot`.  The `gnuplot` help can be put
inside any system help library, allowing access to help from both
within and outside `gnuplot` if desired.

   On Unix, HOME is used as the name of a directory to search for a
.gnuplot file if none is found in the current directory.  On MS-DOS,
Windows and OS/2, GNUPLOT is used.  On Windows, the NT-specific
variable USERPROFILE is also tried. VMS, SYS$LOGIN: is used. Type `help
startup`.

   On Unix, PAGER is used as an output filter for help messages.

   On Unix, SHELL is used for the *note shell:: command.  On MS-DOS and
OS/2, COMSPEC is used for the *note shell:: command.

   FIT_SCRIPT may be used to specify a `gnuplot` command to be executed
when a fit is interrupted--see *note fit::.  FIT_LOG specifies the
default filename of the logfile maintained by fit.

   GNUPLOT_LIB may be used to define additional search directories for
data and command files. The variable may contain a single directory
name, or a list of directories separated by a platform-specific path
separator, eg. ':' on Unix, or ';' on DOS/Windows/OS/2 platforms. The
contents of GNUPLOT_LIB are appended to the *note loadpath:: variable,
but not saved with the *note save:: and `save set` commands.

   Several gnuplot terminal drivers access TrueType fonts via the gd
library.  For these drivers the font search path is controlled by the
environmental variable GDFONTPATH.  Furthermore, a default font for
these drivers may be set via the environmental variable
GNUPLOT_DEFAULT_GDFONT.

   The postscript terminal uses its own font search path. It is
controlled by the environmental variable GNUPLOT_FONTPATH. The format
is the same as for GNUPLOT_LIB. The contents of GNUPLOT_FONTPATH are
appended to the *note fontpath:: variable, but not saved with the *note
save:: and `save set` commands.

   GNUPLOT_PS_DIR is used by the postscript driver to search for
external prologue files. Depending on the build process, gnuplot
contains either a built-in copy of those files or a default hardcoded
path. You can use this variable have the postscript terminal use custom
prologue files rather than the default files. See `postscript prologue`.


File: gnuplot.info,  Node: Expressions,  Next: Fonts,  Prev: Environment,  Up: gnuplot

1.14 Expressions
================

In general, any mathematical expression accepted by C, FORTRAN, Pascal,
or BASIC is valid.  The precedence of these operators is determined by
the specifications of the C programming language.  White space (spaces
and tabs) is ignored inside expressions.

   Complex constants are expressed as {<real>,<imag>}, where <real> and
<imag> must be numerical constants.  For example, {3,2} represents 3 +
2i; {0,1} represents 'i' itself.  The curly braces are explicitly
required here.

   Note that gnuplot uses both "real" and "integer" arithmetic, like
FORTRAN and C.  Integers are entered as "1", "-10", etc; reals as
"1.0", "-10.0", "1e1", 3.5e-1, etc.  The most important difference
between the two forms is in division: division of integers truncates:
5/2 = 2; division of reals does not: 5.0/2.0 = 2.5.  In mixed
expressions, integers are "promoted" to reals before evaluation: 5/2e0
= 2.5.  The result of division of a negative integer by a positive one
may vary among compilers.  Try a test like "print -5/2" to determine if
your system chooses -2 or -3 as the answer.

   The integer expression "1/0" may be used to generate an "undefined"
flag, which causes a point to ignored.  Or you can use the pre-defined
variable NaN to achieve the same result.  See *note using:: for an
example.  

   The real and imaginary parts of complex expressions are always real,
whatever the form in which they are entered: in {3,2} the "3" and "2"
are reals, not integers.

   Gnuplot can also perform simple operations on strings and string
variables.  For example, the expression ("A" . "B" eq "AB") evaluates
as true, illustrating the string concatenation operator and the string
equality operator.

   A string which contains a numerical value is promoted to the
corresponding integer or real value if used in a numerical expression.
Thus ("3" + "4" == 7) and (6.78 == "6.78") both evaluate to true.  An
integer, but not a real or complex value, is promoted to a string if
used in string concatenation.  A typical case is the use of integers to
construct file names or other strings; e.g. ("file" . 4 eq "file4") is
true.

   Substrings can be specified using a postfixed range descriptor
[beg:end].  For example, "ABCDEF"[3:4] == "CD"   and   "ABCDEF"[4:*] ==
"DEF" The syntax "string"[beg:end] is exactly equivalent to calling the
built-in string-valued function substr("string",beg,end), except that
you cannot omit either beg or end from the function call.

* Menu:

* Functions::
* Operators::
* Summation::
* Gnuplot-defined_variables::
* User-defined_variables_and_functions::


File: gnuplot.info,  Node: Functions,  Next: Operators,  Prev: Expressions,  Up: Expressions

1.14.1 Functions
----------------

The math functions in `gnuplot` are the same as the corresponding
functions in the Unix math library, except that all functions accept
integer, real, and complex arguments unless otherwise noted.  Functions
that accept or return angles (e.g. sin(x), cos(x), arg(z)) treat angle
values as radians, but this may be changed to degrees using the command
*note angles::.

* Menu:

* abs::
* acos::
* acosh::
* airy::
* arg::
* asin::
* asinh::
* atan::
* atan2::
* atanh::
* EllipticK::
* EllipticE::
* EllipticPi::
* besj0::
* besj1::
* besy0::
* besy1::
* ceil::
* cos::
* cosh::
* erf::
* erfc::
* exp::
* expint::
* floor::
* gamma::
* ibeta::
* inverf::
* igamma::
* imag::
* invnorm::
* int::
* lambertw::
* lgamma::
* log::
* log10::
* norm::
* rand::
* real::
* sgn::
* sin::
* sinh::
* sqrt::
* tan::
* tanh::
* voigt::
* gprintf::
* sprintf::
* strlen::
* strstrt::
* substr::
* strftime::
* strptime::
* system::
* word::
* words::
* column::
* columnhead::
* defined::
* exists::
* stringcolumn::
* timecolumn::
* tm_hour::
* tm_mday::
* tm_min::
* tm_mon::
* tm_sec::
* tm_wday::
* tm_yday::
* tm_year::
* time::
* valid::
* elliptic_integrals::
* Random_number_generator::
* value::


File: gnuplot.info,  Node: abs,  Next: acos,  Prev: Functions,  Up: Functions

1.14.1.1 abs
............

The `abs(x)` function returns the absolute value of its argument.  The
returned value is of the same type as the argument.

   For complex arguments, abs(x) is defined as the length of x in the
complex plane [i.e.,  sqrt(real(x)**2 + imag(x)**2) ].


File: gnuplot.info,  Node: acos,  Next: acosh,  Prev: abs,  Up: Functions

1.14.1.2 acos
.............

The `acos(x)` function returns the arc cosine (inverse cosine) of its
argument.  `acos` returns its argument in radians or degrees, as
selected by *note angles::.


File: gnuplot.info,  Node: acosh,  Next: airy,  Prev: acos,  Up: Functions

1.14.1.3 acosh
..............

The `acosh(x)` function returns the inverse hyperbolic cosine of its
argument in radians.


File: gnuplot.info,  Node: airy,  Next: arg,  Prev: acosh,  Up: Functions

1.14.1.4 airy
.............

The `airy(x)` function returns the value of the Airy function Ai(x) of
its argument. The function Ai(x) is that solution of the equation y" -
x y = 0 which is everywhere finite. If the argument is complex, its
imaginary part is ignored.


File: gnuplot.info,  Node: arg,  Next: asin,  Prev: airy,  Up: Functions

1.14.1.5 arg
............

The `arg(x)` function returns the phase of a complex number in radians
or degrees, as selected by *note angles::.


File: gnuplot.info,  Node: asin,  Next: asinh,  Prev: arg,  Up: Functions

1.14.1.6 asin
.............

The `asin(x)` function returns the arc sin (inverse sin) of its
argument.  `asin` returns its argument in radians or degrees, as
selected by *note angles::.


File: gnuplot.info,  Node: asinh,  Next: atan,  Prev: asin,  Up: Functions

1.14.1.7 asinh
..............

The `asinh(x)` function returns the inverse hyperbolic sin of its
argument in radians.


File: gnuplot.info,  Node: atan,  Next: atan2,  Prev: asinh,  Up: Functions

1.14.1.8 atan
.............

The `atan(x)` function returns the arc tangent (inverse tangent) of its
argument.  `atan` returns its argument in radians or degrees, as
selected by *note angles::.


File: gnuplot.info,  Node: atan2,  Next: atanh,  Prev: atan,  Up: Functions

1.14.1.9 atan2
..............

The `atan2(y,x)` function returns the arc tangent (inverse tangent) of
the ratio of the real parts of its arguments.  *note atan2:: returns
its argument in radians or degrees, as selected by *note angles::, in
the correct quadrant.


File: gnuplot.info,  Node: atanh,  Next: EllipticK,  Prev: atan2,  Up: Functions

1.14.1.10 atanh
...............

The `atanh(x)` function returns the inverse hyperbolic tangent of its
argument in radians.


File: gnuplot.info,  Node: EllipticK,  Next: EllipticE,  Prev: atanh,  Up: Functions

1.14.1.11 EllipticK
...................

See `elliptic integrals`.


File: gnuplot.info,  Node: EllipticE,  Next: EllipticPi,  Prev: EllipticK,  Up: Functions

1.14.1.12 EllipticE
...................

See `elliptic integrals`.


File: gnuplot.info,  Node: EllipticPi,  Next: besj0,  Prev: EllipticE,  Up: Functions

1.14.1.13 EllipticPi
....................

See `elliptic integrals`.


File: gnuplot.info,  Node: besj0,  Next: besj1,  Prev: EllipticPi,  Up: Functions

1.14.1.14 besj0
...............

The `besj0(x)` function returns the j0th Bessel function of its
argument.  *note besj0:: expects its argument to be in radians.


File: gnuplot.info,  Node: besj1,  Next: besy0,  Prev: besj0,  Up: Functions

1.14.1.15 besj1
...............

The `besj1(x)` function returns the j1st Bessel function of its
argument.  *note besj1:: expects its argument to be in radians.


File: gnuplot.info,  Node: besy0,  Next: besy1,  Prev: besj1,  Up: Functions

1.14.1.16 besy0
...............

The `besy0(x)` function returns the y0th Bessel function of its
argument.  *note besy0:: expects its argument to be in radians.


File: gnuplot.info,  Node: besy1,  Next: ceil,  Prev: besy0,  Up: Functions

1.14.1.17 besy1
...............

The `besy1(x)` function returns the y1st Bessel function of its
argument.  *note besy1:: expects its argument to be in radians.


File: gnuplot.info,  Node: ceil,  Next: cos,  Prev: besy1,  Up: Functions

1.14.1.18 ceil
..............

The `ceil(x)` function returns the smallest integer that is not less
than its argument.  For complex numbers, *note ceil:: returns the
smallest integer not less than the real part of its argument.


File: gnuplot.info,  Node: cos,  Next: cosh,  Prev: ceil,  Up: Functions

1.14.1.19 cos
.............

The `cos(x)` function returns the cosine of its argument.  `cos`
accepts its argument in radians or degrees, as selected by *note
angles::.


File: gnuplot.info,  Node: cosh,  Next: erf,  Prev: cos,  Up: Functions

1.14.1.20 cosh
..............

The `cosh(x)` function returns the hyperbolic cosine of its argument.
*note cosh:: expects its argument to be in radians.


File: gnuplot.info,  Node: erf,  Next: erfc,  Prev: cosh,  Up: Functions

1.14.1.21 erf
.............

The `erf(x)` function returns the error function of the real part of its
argument.  If the argument is a complex value, the imaginary component
is ignored.  See *note erfc::, *note inverf::, and *note norm::.


File: gnuplot.info,  Node: erfc,  Next: exp,  Prev: erf,  Up: Functions

1.14.1.22 erfc
..............

The `erfc(x)` function returns 1.0 - the error function of the real
part of its argument.  If the argument is a complex value, the
imaginary component is ignored.  See `erf`, *note inverf::, and *note
norm::.


File: gnuplot.info,  Node: exp,  Next: expint,  Prev: erfc,  Up: Functions

1.14.1.23 exp
.............

The `exp(x)` function returns the exponential function of its argument
(`e` raised to the power of its argument).  On some implementations
(notably suns), exp(-x) returns undefined for very large x.  A
user-defined function like safe(x) = x<-100 ? 0 : exp(x) might prove
useful in these cases.


File: gnuplot.info,  Node: expint,  Next: floor,  Prev: exp,  Up: Functions

1.14.1.24 expint
................

The `expint(n,x)` function returns the exponential integral of the real
part of its argument: integral from 1 to infinity of t^(-n) e^(-tx) dt.
n must be a nonnegative integer, x>=0, and either x>0 or n>1.


File: gnuplot.info,  Node: floor,  Next: gamma,  Prev: expint,  Up: Functions

1.14.1.25 floor
...............

The `floor(x)` function returns the largest integer not greater than its
argument.  For complex numbers, *note floor:: returns the largest
integer not greater than the real part of its argument.


File: gnuplot.info,  Node: gamma,  Next: ibeta,  Prev: floor,  Up: Functions

1.14.1.26 gamma
...............

The `gamma(x)` function returns the gamma function of the real part of
its argument.  For integer n, gamma(n+1) = n!.  If the argument is a
complex value, the imaginary component is ignored.


File: gnuplot.info,  Node: ibeta,  Next: inverf,  Prev: gamma,  Up: Functions

1.14.1.27 ibeta
...............

The `ibeta(p,q,x)` function returns the incomplete beta function of the
real parts of its arguments. p, q > 0 and x in [0:1].  If the arguments
are complex, the imaginary components are ignored.  The function is
approximated by the method of continued fractions (Abramowitz and
Stegun, 1964).  The approximation is only accurate in the region x <
(p-1)/(p+q-2).


File: gnuplot.info,  Node: inverf,  Next: igamma,  Prev: ibeta,  Up: Functions

1.14.1.28 inverf
................

The `inverf(x)` function returns the inverse error function of the real
part of its argument.   See `erf` and *note invnorm::.


File: gnuplot.info,  Node: igamma,  Next: imag,  Prev: inverf,  Up: Functions

1.14.1.29 igamma
................

The `igamma(a,x)` function returns the normalized incomplete gamma
function of the real parts of its arguments, where a > 0 and x >= 0.
The standard notation is P(a,x), e.g. Abramowitz and Stegun (6.5.1),
with limiting value of 1 as x approaches infinity.  If the arguments
are complex, the imaginary components are ignored.


File: gnuplot.info,  Node: imag,  Next: invnorm,  Prev: igamma,  Up: Functions

1.14.1.30 imag
..............

The `imag(x)` function returns the imaginary part of its argument as a
real number.


File: gnuplot.info,  Node: invnorm,  Next: int,  Prev: imag,  Up: Functions

1.14.1.31 invnorm
.................

The `invnorm(x)` function returns the inverse cumulative normal
(Gaussian) distribution function of the real part of its argument.  See
*note norm::.


File: gnuplot.info,  Node: int,  Next: lambertw,  Prev: invnorm,  Up: Functions

1.14.1.32 int
.............

The `int(x)` function returns the integer part of its argument,
truncated toward zero.


File: gnuplot.info,  Node: lambertw,  Next: lgamma,  Prev: int,  Up: Functions

1.14.1.33 lambertw
..................

The lambertw function returns the value of the principal branch of
Lambert's W function, which is defined by the equation
(W(z)*exp(W(z))=z.  z must be a real number with z >= -exp(-1).


File: gnuplot.info,  Node: lgamma,  Next: log,  Prev: lambertw,  Up: Functions

1.14.1.34 lgamma
................

The `lgamma(x)` function returns the natural logarithm of the gamma
function of the real part of its argument.  If the argument is a
complex value, the imaginary component is ignored.


File: gnuplot.info,  Node: log,  Next: log10,  Prev: lgamma,  Up: Functions

1.14.1.35 log
.............

The `log(x)` function returns the natural logarithm (base `e`) of its
argument.  See *note log10::.


File: gnuplot.info,  Node: log10,  Next: norm,  Prev: log,  Up: Functions

1.14.1.36 log10
...............

The `log10(x)` function returns the logarithm (base 10) of its argument.


File: gnuplot.info,  Node: norm,  Next: rand,  Prev: log10,  Up: Functions

1.14.1.37 norm
..............

The `norm(x)` function returns the cumulative normal (Gaussian)
distribution function of the real part of its argument.   See *note
invnorm::, `erf` and *note erfc::.


File: gnuplot.info,  Node: rand,  Next: real,  Prev: norm,  Up: Functions

1.14.1.38 rand
..............

`rand(0)` returns a pseudo random number in the interval [0:1].  See
`random` for more details.


File: gnuplot.info,  Node: real,  Next: sgn,  Prev: rand,  Up: Functions

1.14.1.39 real
..............

The `real(x)` function returns the real part of its argument.


File: gnuplot.info,  Node: sgn,  Next: sin,  Prev: real,  Up: Functions

1.14.1.40 sgn
.............

The `sgn(x)` function returns 1 if its argument is positive, -1 if its
argument is negative, and 0 if its argument is 0.  If the argument is a
complex value, the imaginary component is ignored.


File: gnuplot.info,  Node: sin,  Next: sinh,  Prev: sgn,  Up: Functions

1.14.1.41 sin
.............

The `sin(x)` function returns the sine of its argument.  `sin` expects
its argument to be in radians or degrees, as selected by *note angles::.


File: gnuplot.info,  Node: sinh,  Next: sqrt,  Prev: sin,  Up: Functions

1.14.1.42 sinh
..............

The `sinh(x)` function returns the hyperbolic sine of its argument.
*note sinh:: expects its argument to be in radians.


File: gnuplot.info,  Node: sqrt,  Next: tan,  Prev: sinh,  Up: Functions

1.14.1.43 sqrt
..............

The `sqrt(x)` function returns the square root of its argument.


File: gnuplot.info,  Node: tan,  Next: tanh,  Prev: sqrt,  Up: Functions

1.14.1.44 tan
.............

The `tan(x)` function returns the tangent of its argument.  `tan`
expects its argument to be in radians or degrees, as selected by *note
angles::.


File: gnuplot.info,  Node: tanh,  Next: voigt,  Prev: tan,  Up: Functions

1.14.1.45 tanh
..............

The `tanh(x)` function returns the hyperbolic tangent of its argument.
*note tanh:: expects its argument to be in radians.


File: gnuplot.info,  Node: voigt,  Next: gprintf,  Prev: tanh,  Up: Functions

1.14.1.46 voigt
...............

The function `voigt(x,y)` returns an approximation to the Voigt/Faddeeva
function used in spectral analysis. The approximation is accurate to
one part in 10^4.


File: gnuplot.info,  Node: gprintf,  Next: sprintf,  Prev: voigt,  Up: Functions

1.14.1.47 gprintf
.................

`gprintf("format",x)` applies gnuplot's own format specifiers to the
single variable x and returns the resulting string. If you want
standard C-language format specifiers, you must instead use
`sprintf("format",x)`.  See `format specifiers`.


File: gnuplot.info,  Node: sprintf,  Next: strlen,  Prev: gprintf,  Up: Functions

1.14.1.48 sprintf
.................

`sprintf("format",var1,var2,...)` applies standard C-language format
specifiers to multiple arguments and returns the resulting string. If
you want to use gnuplot's own format specifiers, you must instead call
`gprintf()`.  For information on sprintf format specifiers, please see
standard C-language documentation or the unix sprintf man page.


File: gnuplot.info,  Node: strlen,  Next: strstrt,  Prev: sprintf,  Up: Functions

1.14.1.49 strlen
................

`strlen("string")` returns the length of the string in bytes.  If the
current encoding supports multibyte characters, this may be larger than
the number of characters in the string.


File: gnuplot.info,  Node: strstrt,  Next: substr,  Prev: strlen,  Up: Functions

1.14.1.50 strstrt
.................

`strstrt("string","key")` searches for the character string "key" in
"string" and returns the index to the first character of "key". If
"key" is not found, returns 0. Similar to C library function strstr
except that it returns an index rather than a string pointer.
strstrt("hayneedlestack","needle") = 4.


File: gnuplot.info,  Node: substr,  Next: strftime,  Prev: strstrt,  Up: Functions

1.14.1.51 substr
................

`substr("string",beg,end)` returns the substring consisting of
characters beg through end of the original string. This is exactly
equivalent to the expression "string"[beg:end] except that you do not
have the option of omitting beg or end.


File: gnuplot.info,  Node: strftime,  Next: strptime,  Prev: substr,  Up: Functions

1.14.1.52 strftime
..................

`strftime("timeformat",t)` applies the timeformat specifiers to the
time t given in seconds since the year 2000.  See `time_specifiers` and
*note strptime::.


File: gnuplot.info,  Node: strptime,  Next: system,  Prev: strftime,  Up: Functions

1.14.1.53 strptime
..................

`strptime("timeformat",s)` reads the time from the string s using the
timeformat specifiers and converts it into seconds since the year 2000.
See `time_specifiers` and *note strftime::.


File: gnuplot.info,  Node: system,  Next: word,  Prev: strptime,  Up: Functions

1.14.1.54 system
................

`system("command")` executes "command" using the standard shell and
returns the resulting character stream from stdout as string variable.
One optional trailing newline is ignored.

   This can be used to import external functions into gnuplot scripts
using 'f(x) = real(system(sprintf("somecommand %f", x)))'.


File: gnuplot.info,  Node: word,  Next: words,  Prev: system,  Up: Functions

1.14.1.55 word
..............

`word("string",n)` returns the nth word in string. For example,
`word("one two three",2)` returns the string "two".


File: gnuplot.info,  Node: words,  Next: column,  Prev: word,  Up: Functions

1.14.1.56 words
...............

`words("string")` returns the number of words in string. For example,
`words(" a b c d")` returns 4.


File: gnuplot.info,  Node: column,  Next: columnhead,  Prev: words,  Up: Functions

1.14.1.57 column
................

`column(x)` may be used only in expressions as part of *note using::
manipulations to fits or datafile plots.  It evaluates to the numerical
value of the contents of column x. See *note using::.


File: gnuplot.info,  Node: columnhead,  Next: defined,  Prev: column,  Up: Functions

1.14.1.58 columnhead
....................

`columnhead(x)` may only be used in expressions as part of *note
using:: manipulations to fits or datafile plots.  It evaluates to a
string containing the contents of column x in the first line of data.
See *note using::.


File: gnuplot.info,  Node: defined,  Next: exists,  Prev: columnhead,  Up: Functions

1.14.1.59 defined
.................

`defined(X)` [DEPRECATED] returns 1 if a variable named X has been
defined, otherwise it returns 0.


File: gnuplot.info,  Node: exists,  Next: stringcolumn,  Prev: defined,  Up: Functions

1.14.1.60 exists
................

The argument to exists() is a string constant or a string variable; if
the string contains the name of a defined variable, the function
returns 1.  Otherwise the function returns 0.


File: gnuplot.info,  Node: stringcolumn,  Next: timecolumn,  Prev: exists,  Up: Functions

1.14.1.61 stringcolumn
......................

`stringcolumn(x)` may be used only in expressions as part of *note
using:: manipulations to fits or datafile plots.  It returns the
content of column x as a string variable.  See *note using::.


File: gnuplot.info,  Node: timecolumn,  Next: tm_hour,  Prev: stringcolumn,  Up: Functions

1.14.1.62 timecolumn
....................

`timecolumn(x)` may be used only in expressions as part of *note using::
manipulations to fits or datafile plots.   See *note using::.

   It reads the data starting at that column as a time/date value and
returns its value in gnuplot's internal time representation of "seconds
since the millennium".

   To find the right *note timefmt:: string to use, *note timecolumn::
searches for a *note using:: specification with the same column number
as its argument.  If one is found, *note timefmt:: pattern of the
target axis for this specifier is used.  Otherwise, *note timecolumn::
chooses the x axis *note timefmt:: per default.


File: gnuplot.info,  Node: tm_hour,  Next: tm_mday,  Prev: timecolumn,  Up: Functions

1.14.1.63 tm_hour
.................

The *note tm_hour:: function interprets its argument as a time, in
seconds from 1 Jan 2000.  It returns the hour (an integer in the range
0-23) as a real.


File: gnuplot.info,  Node: tm_mday,  Next: tm_min,  Prev: tm_hour,  Up: Functions

1.14.1.64 tm_mday
.................

The *note tm_mday:: function interprets its argument as a time, in
seconds from 1 Jan 2000.  It returns the day of the month (an integer
in the range 1-31) as a real.


File: gnuplot.info,  Node: tm_min,  Next: tm_mon,  Prev: tm_mday,  Up: Functions

1.14.1.65 tm_min
................

The *note tm_min:: function interprets its argument as a time, in
seconds from 1 Jan 2000.  It returns the minute (an integer in the
range 0-59) as a real.


File: gnuplot.info,  Node: tm_mon,  Next: tm_sec,  Prev: tm_min,  Up: Functions

1.14.1.66 tm_mon
................

The *note tm_mon:: function interprets its argument as a time, in
seconds from 1 Jan 2000.  It returns the month (an integer in the range
0-11) as a real.


File: gnuplot.info,  Node: tm_sec,  Next: tm_wday,  Prev: tm_mon,  Up: Functions

1.14.1.67 tm_sec
................

The *note tm_sec:: function interprets its argument as a time, in
seconds from 1 Jan 2000.  It returns the second (an integer in the
range 0-59) as a real.


File: gnuplot.info,  Node: tm_wday,  Next: tm_yday,  Prev: tm_sec,  Up: Functions

1.14.1.68 tm_wday
.................

The *note tm_wday:: function interprets its argument as a time, in
seconds from 1 Jan 2000.  It returns the day of the week (an integer in
the range 0-6) as a real.


File: gnuplot.info,  Node: tm_yday,  Next: tm_year,  Prev: tm_wday,  Up: Functions

1.14.1.69 tm_yday
.................

The *note tm_yday:: function interprets its argument as a time, in
seconds from 1 Jan 2000.  It returns the day of the year (an integer in
the range 1-366) as a real.


File: gnuplot.info,  Node: tm_year,  Next: time,  Prev: tm_yday,  Up: Functions

1.14.1.70 tm_year
.................

The *note tm_year:: function interprets its argument as a time, in
seconds from 1 Jan 2000.  It returns the year (an integer) as a real.


File: gnuplot.info,  Node: time,  Next: valid,  Prev: tm_year,  Up: Functions

1.14.1.71 time
..............

The `time` function returns the current system time. This value can be
converted to a date string with the *note strftime:: function, or it
can be used in conjunction with *note timecolumn:: to generate relative
time/date plots.  The type of the argument determines what is returned.
If the argument is an integer, time() returns the current time as an
integer, in seconds from 1 Jan 2000. If the argument is real (or
complex), the result is real as well.  If the argument is a string, it
is assumed to be a format string, and it is passed to *note strftime::
to provide a formatted time string.


File: gnuplot.info,  Node: valid,  Next: elliptic_integrals,  Prev: time,  Up: Functions

1.14.1.72 valid
...............

`valid(x)` may be used only in expressions as part of *note using::
manipulations to fits or datafile plots.  See *note using::.


File: gnuplot.info,  Node: elliptic_integrals,  Next: Random_number_generator,  Prev: valid,  Up: Functions

1.14.1.73 elliptic integrals
............................

The `EllipticK(k)` function returns the complete elliptic integral of
the first kind, i.e. the definite integral between 0 and pi/2 of the
function `(1-(k*sin(p))**2)**(-0.5)`.  The domain of `k` is -1 to 1
(exclusive).

   The `EllipticE(k)` function returns the complete elliptic integral
of the second kind, i.e. the definite integral between 0 and pi/2 of
the function `(1-(k*sin(p))**2)**0.5`.  The domain of `k` is -1 to 1
(inclusive).

   The `EllipticPi(n,k)` function returns the complete elliptic
integral of the third kind, i.e. the definite integral between 0 and
pi/2 of the function `(1-(k*sin(p))**2)**(-0.5)/(1-n*sin(p)**2)`.  The
parameter `n` must be less than 1, while `k` must lie between -1 and 1
(exclusive).  Note that by definition EllipticPi(0,k) == EllipticK(k)
for all possible values of `k`.


File: gnuplot.info,  Node: Random_number_generator,  Next: value,  Prev: elliptic_integrals,  Up: Functions

1.14.1.74 Random number generator
.................................

The function `rand()` produces a sequence of pseudo-random numbers
between 0 and 1 using an algorithm from P. L'Ecuyer and S. Cote,
"Implementing a random number package with splitting facilities", ACM
Transactions on Mathematical Software, 17:98-111 (1991).

           rand(0)     returns a pseudo random number in the interval [0:1]
                       generated from the current value of two internal
                       32-bit seeds.
           rand(-1)    resets both seeds to a standard value.
           rand(x)     for integer 0 < x < 2^31-1 sets both internal seeds
                       to x.
           rand({x,y}) for integer 0 < x,y < 2^31-1 sets seed1 to x and
                       seed2 to y.


File: gnuplot.info,  Node: value,  Prev: Random_number_generator,  Up: Functions

1.14.1.75 value
...............

B = value("A") is effectively the same as B = A, where A is the name of
a user-defined variable.  This is useful when the name of the variable
is itself held in a string variable. See *note variables::.  It also
allows you to read the name of a variable from a data file.  If the
argument is a numerical expression, value() returns the value of that
expression.  If the argument is a string that does not correspond to a
currently defined variable, value() returns NaN.


File: gnuplot.info,  Node: Operators,  Next: Summation,  Prev: Functions,  Up: Expressions

1.14.2 Operators
----------------

The operators in `gnuplot` are the same as the corresponding operators
in the C programming language, except that all operators accept
integer, real, and complex arguments, unless otherwise noted.  The **
operator (exponentiation) is supported, as in FORTRAN.

   Parentheses may be used to change order of evaluation.

* Menu:

* Unary::
* Binary::
* Ternary::


File: gnuplot.info,  Node: Unary,  Next: Binary,  Prev: Operators,  Up: Operators

1.14.2.1 Unary
..............

The following is a list of all the unary operators and their usages:

         Symbol      Example    Explanation
           -           -a          unary minus
           +           +a          unary plus (no-operation)
           ~           ~a        * one's complement
           !           !a        * logical negation
           !           a!        * factorial
           $           $3        * call arg/column during *note using:: manipulation

   (*) Starred explanations indicate that the operator requires an
integer argument.

   Operator precedence is the same as in Fortran and C.  As in those
languages, parentheses may be used to change the order of operation.
Thus -2**2 = -4, but (-2)**2 = 4.

   The factorial operator returns a real number to allow a greater
range.


File: gnuplot.info,  Node: Binary,  Next: Ternary,  Prev: Unary,  Up: Operators

1.14.2.2 Binary
...............

The following is a list of all the binary operators and their usages:

         Symbol       Example      Explanation
           **          a**b          exponentiation
           *           a*b           multiplication
           /           a/b           division
           %           a%b         * modulo
           +           a+b           addition
           -           a-b           subtraction
           ==          a==b          equality
           !=          a!=b          inequality
           <           a<b           less than
           <=          a<=b          less than or equal to
           >           a>b           greater than
           >=          a>=b          greater than or equal to
           &           a&b         * bitwise AND
           ^           a^b         * bitwise exclusive OR
           |           a|b         * bitwise inclusive OR
           &&          a&&b        * logical AND
           ||          a||b        * logical OR
           =           a = b         assignment
           ,           (a,b)         serial evaluation
           .           A.B           string concatenation
           eq          A eq B        string equality
           ne          A ne B        string inequality

   (*) Starred explanations indicate that the operator requires integer
arguments.  Capital letters A and B indicate that the operator requires
string arguments.

   Logical AND (&&) and OR (||) short-circuit the way they do in C.
That is, the second `&&` operand is not evaluated if the first is
false; the second `||` operand is not evaluated if the first is true.

   Serial evaluation occurs only in parentheses and is guaranteed to
proceed in left to right order.  The value of the rightmost
subexpression is returned.


File: gnuplot.info,  Node: Ternary,  Prev: Binary,  Up: Operators

1.14.2.3 Ternary
................

There is a single ternary operator:

         Symbol       Example      Explanation
           ?:          a?b:c     ternary operation

   The ternary operator behaves as it does in C.  The first argument
(a), which must be an integer, is evaluated.  If it is true (non-zero),
the second argument (b) is evaluated and returned; otherwise the third
argument (c) is evaluated and returned.

   The ternary operator is very useful both in constructing piecewise
functions and in plotting points only when certain conditions are met.

   Examples:

   Plot a function that is to equal sin(x) for 0 <= x < 1, 1/x for 1 <=
x < 2, and undefined elsewhere:
           f(x) = 0<=x && x<1 ? sin(x) : 1<=x && x<2 ? 1/x : 1/0
           plot f(x)

   Note that `gnuplot` quietly ignores undefined values, so the final
branch of the function (1/0) will produce no plottable points.  Note
also that f(x) will be plotted as a continuous function across the
discontinuity if a line style is used.  To plot it discontinuously,
create separate functions for the two pieces.  (Parametric functions
are also useful for this purpose.)

   For data in a file, plot the average of the data in columns 2 and 3
against the datum in column 1, but only if the datum in column 4 is
non-negative:

           plot 'file' using 1:( $4<0 ? 1/0 : ($2+$3)/2 )

   For an explanation of the *note using:: syntax, please see *note
using::.


File: gnuplot.info,  Node: Summation,  Next: Gnuplot-defined_variables,  Prev: Operators,  Up: Expressions

1.14.3 Summation
----------------

A summation expression has the form
           sum [<var> = <start> : <end>] <expression>

   <var> is treated as an integer variable that takes on successive
integral values from <start> to <end>.  For each of these, the current
value of <expression> is added to a running total whose final value
becomes the value of the summation expression.  Examples:
           print sum [i=1:10] i
               55.
           # Equivalent to plot 'data' using 1:($2+$3+$4+$5+$6+...)
           plot 'data' using 1 : (sum [col=2:MAXCOL] column(col))

   It is not necessary that <expression> contain the variable <var>.
Although <start> and <end> can be specified as variables or expressions,
their value cannot be changed dynamically as a side-effect of carrying
out the summation. If <end> is less than <start> then the value of the
summation is zero.


File: gnuplot.info,  Node: Gnuplot-defined_variables,  Next: User-defined_variables_and_functions,  Prev: Summation,  Up: Expressions

1.14.4 Gnuplot-defined variables
--------------------------------

Gnuplot maintains a number of read-only variables that reflect the
current internal state of the program and the most recent plot. These
variables begin with the prefix "GPVAL_".  Examples include GPVAL_TERM,
GPVAL_X_MIN, GPVAL_X_MAX, GPVAL_Y_MIN.  Type `show variables all` to
display the complete list and current values.  Values related to axes
parameters (ranges, log base) are values used during the last plot, not
those currently `set`.

   Example:  To calculate the fractional screen coordinates of the
point [X,Y]
          GRAPH_X = (X - GPVAL_X_MIN) / (GPVAL_X_MAX - GPVAL_X_MIN)
          GRAPH_Y = (Y - GPVAL_Y_MIN) / (GPVAL_Y_MAX - GPVAL_Y_MIN)
          SCREEN_X = GPVAL_TERM_XMIN + GRAPH_X * (GPVAL_TERM_XMAX - GPVAL_TERM_XMIN)
          SCREEN_Y = GPVAL_TERM_YMIN + GRAPH_Y * (GPVAL_TERM_YMAX - GPVAL_TERM_YMIN)
          FRAC_X = SCREEN_X / GPVAL_TERM_XSIZE
          FRAC_Y = SCREEN_Y / GPVAL_TERM_YSIZE

   The read-only variable GPVAL_ERRNO is set to a non-zero value if any
gnuplot command terminates early due to an error.  The most recent
error message is stored in the string variable GPVAL_ERRMSG.  Both
GPVAL_ERRNO and GPVAL_ERRMSG can be cleared using the command `reset
errors`.

   Interactive terminals with `mouse` functionality maintain read-only
variables with the prefix "MOUSE_".  See *note variables:: for details.

   The *note fit:: mechanism uses several variables with names that
begin "FIT_".  It is safest to avoid using such names.  "FIT_LIMIT",
however, is one that you may wish to redefine. Under `set fit
errorvariables`, the error for each fitted parameter will be stored in
a variable named like the parameter, but with "_err" appended. See the
documentation on *note fit:: for details.

   See *note variables::, `reset errors`, *note variables::, and *note
fit::.


File: gnuplot.info,  Node: User-defined_variables_and_functions,  Prev: Gnuplot-defined_variables,  Up: Expressions

1.14.5 User-defined variables and functions
-------------------------------------------

New user-defined variables and functions of one through twelve
variables may be declared and used anywhere, including on the `plot`
command itself.

   User-defined function syntax:
           <func-name>( <dummy1> {,<dummy2>} ... {,<dummy12>} ) = <expression>

   where <expression> is defined in terms of <dummy1> through <dummy12>.

   User-defined variable syntax:
           <variable-name> = <constant-expression>

   Examples:
           w = 2
           q = floor(tan(pi/2 - 0.1))
           f(x) = sin(w*x)
           sinc(x) = sin(pi*x)/(pi*x)
           delta(t) = (t == 0)
           ramp(t) = (t > 0) ? t : 0
           min(a,b) = (a < b) ? a : b
           comb(n,k) = n!/(k!*(n-k)!)
           len3d(x,y,z) = sqrt(x*x+y*y+z*z)
           plot f(x) = sin(x*a), a = 0.2, f(x), a = 0.4, f(x)

           file = "mydata.inp"
           file(n) = sprintf("run_%d.dat",n)

   The final two examples illustrate a user-defined string variable and
a user-defined string function.

   Note that the variables `pi` (3.14159...) and `NaN` (IEEE "Not a
Number") are already defined.  You can redefine these to something else
if you really need to. The original values can be recovered by setting:

           NaN = GPVAL_NaN
           pi  = GPVAL_pi

   Other variables may be defined under various gnuplot operations like
mousing in interactive terminals or fitting; see *note variables:: for
details.

   You can check for existence of a given variable V by the exists("V")
expression. For example
           a = 10
           if (exists("a")) print "a is defined"
           if (!exists("b")) print "b is not defined"

   Valid names are the same as in most programming languages: they must
begin with a letter, but subsequent characters may be letters, digits,
or "_".

   Each function definition is made available as a special string-valued
variable with the prefix 'GPFUN_'.

   Example:
           set label GPFUN_sinc at graph .05,.95

   See *note functions::, *note functions::, *note variables::, *note
macros::, *note value::.


File: gnuplot.info,  Node: Fonts,  Next: Glossary,  Prev: Expressions,  Up: gnuplot

1.15 Fonts
==========

Gnuplot does not provide any fonts of its own. It relies on external
font handling, the details of which unfortunately vary from one
terminal type to another. Brief documentation of font mechanisms that
apply to more than one terminal type is given here. For information on
font use by other individual terminals, see the documentation for that
terminal.

* Menu:

* cairo_(pdfcairo::
* gd_(png::
* postscript__(also_encapsulated_postscript_*.eps)::


File: gnuplot.info,  Node: cairo_(pdfcairo,  Next: gd_(png,  Prev: Fonts,  Up: Fonts

1.15.1 cairo (pdfcairo, pngcairo, epscairo, wxt terminals)
----------------------------------------------------------

Sorry, this section is under construction.  These terminals find and
access fonts using the external fontconfig tool set.  Please see the
fontconfig user manual. (http://fontconfig.org/fontconfig-user.html) It
is usually sufficient in gnuplot to request a font by a generic name and
size, letting fontconfig substitute a similar font if necessary. The
following will probably all work:
          set term pdfcairo font "sans,12"
          set term pdfcairo font "Times,12"
          set term pdfcairo font "Times-New-Roman,12"


File: gnuplot.info,  Node: gd_(png,  Next: postscript__(also_encapsulated_postscript_*.eps),  Prev: cairo_(pdfcairo,  Up: Fonts

1.15.2 gd (png, gif, jpeg terminals)
------------------------------------

Font handling for the png, gif, and jpeg terminals is done by the
external library libgd.  Five basic fonts are provided directly by
libgd. These are `tiny` (5x8 pixels), `small` (6x12 pixels), `medium`,
(7x13 Bold), `large` (8x16) or `giant` (9x15 pixels). These fonts
cannot be scaled or rotated.  Use one of these keywords instead of the
`font` keyword. E.g.
          set term png tiny

   On most systems libgd also provides access to Adobe Type 1 fonts
(*.pfa) and TrueType fonts (*.ttf). You must give the name of the font
file, not the name of the font inside it, in the form "<face>
{,<pointsize>}".  <face> is either the full pathname to the font file,
or the first part of a filename in one of the directories listed in the
GDFONTPATH environmental variable. That is, 'set term png font "Face"'
will look for a font file named either <somedirectory>/Face.ttf or
<somedirectory>/Face.pfa.  For example, if GDFONTPATH contains
`/usr/local/fonts/ttf:/usr/local/fonts/pfa` then the following pairs of
commands are equivalent
          set term png font "arial"
          set term png font "/usr/local/fonts/ttf/arial.ttf"
          set term png font "Helvetica"
          set term png font "/usr/local/fonts/pfa/Helvetica.pfa"

   To request a default font size at the same time:
          set term png font "arial,11"

   Both TrueType and Adobe Type 1 fonts are fully scalable and
rotatable.  If no specific font is requested in the "set term" command,
gnuplot checks the environmental variable GNUPLOT_DEFAULT_GDFONT to see
if there is a preferred default font.


File: gnuplot.info,  Node: postscript__(also_encapsulated_postscript_*.eps),  Prev: gd_(png,  Up: Fonts

1.15.3 postscript  (also encapsulated postscript *.eps)
-------------------------------------------------------

PostScript font handling is done by the printer or viewing program.
Gnuplot can create valid PostScript or encapsulated PostScript (*.eps)
even if no fonts at all are installed on your computer.  Gnuplot simply
refers to the font by name in the output file, and assumes that the
printer or viewing program will know how to find or approximate a font
by that name.

   All PostScript printers or viewers should know about the standard
set of Adobe fonts `Times-Roman`, `Helvetica`, `Courier`, and `Symbol`.
It is likely that many additional fonts are also available, but the
specific set depends on your system or printer configuration. Gnuplot
does not know or care about this; the output *.ps or *.eps files that
it creates will simply refer to whatever font names you request.

   Thus
          set term postscript eps font "Times-Roman,12"

   will produce output that is suitable for all printers and viewers.

   On the other hand
          set term postscript eps font "Garamond-Premier-Pro-Italic"

   will produce an output file that contains valid PostScript, but
since it refers to a specialized font, only some printers or viewers
will be able to display the specific font that was requested.  Most
will substitute a different font.

   However, it is possible to embed a specific font in the output file
so that all printers will be able to use it. This requires that the a
suitable font description file is available on your system. Note that
some font files require specific licensing if they are to be embedded
in this way.  See `postscript fontfile` for more detailed description
and examples.


File: gnuplot.info,  Node: Glossary,  Next: linetypes,  Prev: Fonts,  Up: gnuplot

1.16 Glossary
=============

Throughout this document an attempt has been made to maintain
consistency of nomenclature.  This cannot be wholly successful because
as `gnuplot` has evolved over time, certain command and keyword names
have been adopted that preclude such perfection.  This section contains
explanations of the way some of these terms are used.

   A "page" or "screen" or "canvas" is the entire area addressable by
`gnuplot`.  On a desktop it is a full window; on a plotter, it is a
single sheet of paper; in svga mode it is the full monitor screen.

   A screen may contain one or more "plots".  A plot is defined by an
abscissa and an ordinate, although these need not actually appear on
it, as well as the margins and any text written therein.

   A plot contains one "graph".  A graph is defined by an abscissa and
an ordinate, although these need not actually appear on it.

   A graph may contain one or more "lines".  A line is a single
function or data set.  "Line" is also a plotting style.  The word will
also be used in sense "a line of text".  Presumably the context will
remove any ambiguity.

   The lines on a graph may have individual names.  These may be listed
together with a sample of the plotting style used to represent them in
the "key", sometimes also called the "legend".

   The word "title" occurs with multiple meanings in `gnuplot`.  In this
document, it will always be preceded by the adjective "plot", "line", or
"key" to differentiate among them.  A 2D graph may have up to four
labelled *note axes::.  The names of the four axes are "x" for the axis
along the bottom border of the plot, "y" for the axis along the left
border, "x2" for the top border, and "y2" for the right border.  See
*note axes::.

   A 3D graph may have up to three labelled *note axes:: - "x", "y" and
"z".  It is not possible to say where on the graph any particular axis
will fall because you can change the direction from which the graph is
seen with *note view::.

   When discussing data files, the term "record" will be resurrected
and used to denote a single line of text in the file, that is, the
characters between newline or end-of-record characters.  A "point" is
the datum extracted from a single record.  A "datablock" is a set of
points from consecutive records, delimited by blank records.  A line,
when referred to in the context of a data file, is a subset of a
datablock.


File: gnuplot.info,  Node: linetypes,  Next: mouse_input,  Prev: Glossary,  Up: gnuplot

1.17 linetypes, colors, and styles
==================================

Each gnuplot terminal type provides a set of distinct "linetypes".
These may differ in color, in thickness, in dot/dash pattern, or in
some combination of color and dot/dash. The default linetypes for a
particular terminal can be previewed by issuing the *note test::
command after setting the terminal type.  The pre-defined colors and
dot/dash patterns are not guaranteed to be consistent for all terminal
types, but all terminals use the special linetype -1 to mean a solid
line in the primary foreground color (normally black).  Most terminals
also recognize the special linetype "bgnd" to mean a solid line in the
background color.

   You can redefine the default linetype properties either
interactively or via an initialization file.  This allows you to
customize the colors and other properties of the lines used by all
gnuplot plotting commands.  See `set linetype`.

   By default, successive functions or datafiles plotted by a single
command will be assigned successive linetypes.  You can override this
default sequence by specifying a particular linetype for any function,
datafile, or plot element.

   Examples:

          plot "foo", "bar"                 # plot two files using linetypes 1, 2
          plot sin(x) linetype 4            # terminal-specific linetype color 4
          plot sin(x) lt -1                 # black

   For many terminal types it is also possible to assign user-defined
colors using explicit rgb (red, green, blue) values, named colors, or
color values that refer to the current pm3d palette.

   Examples:

          plot sin(x) lt rgb "violet"       # one of gnuplot's named colors
          plot sin(x) lt rgb "#FF00FF"      # explicit RGB triple in hexadecimal
          plot sin(x) lt palette cb -45     # whatever color corresponds to -45
                                            # in the current cbrange of the palette
          plot sin(x) lt palette frac 0.3   # fractional value along the palette

   See *note colornames::, *note palette::, *note cbrange::.

   For terminals that support dot/dash patterns, each default linetype
has both a dot-dash pattern and a default color. Gnuplot does not
currently provide a mechanism for changing the dot-dash pattern, so if
you want both a particular dash pattern and a particular color you must
first choose a linetype that has the required dash pattern, then
override the default color using the keyword `linecolor`, abbreviated
`lc`.  For example, the postscript terminal provides a dashed blue line
as linetype 3.  The plot commands below use this same dash pattern for
three plots, one in blue (the default), another in red (the default for
linetype 1), and a third in gold.

   Example:

          set term postscript dashed color
          plot 'foo' lt 3, 'baz' lt 3 linecolor 1, 'bar' lt 3 lc rgb 'gold'

* Menu:

* colorspec::
* linestyles_vs_linetypes::


File: gnuplot.info,  Node: colorspec,  Next: linestyles_vs_linetypes,  Prev: linetypes,  Up: linetypes

1.17.1 colorspec
----------------

Many commands allow you to specify a linetype with an explicit color.
Terminal-independent color choice is only possible for terminals that
support RGB color or pm3d palettes.

   Syntax:

           ... {linecolor | lc} {<colorspec> | <n>}
           ... {textcolor | tc} {<colorspec> | {linetype | lt} <n>}

   where <colorspec> has one of the following forms:

           rgbcolor "colorname"
           rgbcolor "#RRGGBB"
           rgbcolor variable       # color is read from input file
           palette frac <val>      # <val> runs from 0 to 1
           palette cb <value>      # <val> lies within cbrange
           palette z
           variable                # color index is read from input file

   The "<n>" is the linetype number the color of which is used, see
*note test::.

   "colorname" refers to one of the color names built in to gnuplot.
For a list of the available names, see *note colornames::.

   "#RRGGBB" is a hexadecimal constant preceded by the "#" symbol. The
RRGGBB represents the red, green, and blue components of the color,
each on a scale from 0 - 255.  For example, magenta = full-scale red +
full-scale blue would be represented by #FF00FF, which is the
hexadecimal representation of (255 << 16) + (0 << 8) + (255).

   The color palette is a linear gradient of colors that smoothly maps a
single numerical value onto a particular color.  Two such mappings are
always in effect. `palette frac`  maps a fractional value between 0 and
1 onto the full range of the color palette.  `palette cb` maps the
range of the color axis onto the same palette.  See *note cbrange::.
See also `set colorbox`.  You can use either of these to select a
constant color from the current palette.

   "palette z" maps the z value of each plot segment or plot element
into the cbrange mapping of the palette. This allows smoothly-varying
color along a 3d line or surface. It also allows coloring 2D plots by
palette values read from an extra column of data (not all 2D plot
styles allow an extra column).

* Menu:

* background_color::
* linecolor_variable::
* rgbcolor_variable::


File: gnuplot.info,  Node: background_color,  Next: linecolor_variable,  Prev: colorspec,  Up: colorspec

1.17.1.1 background color
.........................

Most terminals now allow you to set an explicit background color for
the plot.  The special linetype `bgnd` will draw in this color, and
`bgnd` is also recognized as a color.  Examples:
          # This will erase a section of the canvas by writing over it in the
          # background color
          set term wxt background rgb "gray75"
          set object 1 rectangle from x0,y0 to x1,y1 fillstyle solid fillcolor bgnd
          # This will draw an "invisible" line along the x axis
          plot 0 lt bgnd


File: gnuplot.info,  Node: linecolor_variable,  Next: rgbcolor_variable,  Prev: background_color,  Up: colorspec

1.17.1.2 linecolor variable
...........................

`lc variable` tells the program to use the value read from one column
of the input data as a linetype index, and use the color belonging to
that linetype.  This requires a corresponding additional column in the
*note using:: specifier.  Text colors can be set similarly using `tc
variable`.

   Examples:
           # Use the third column of data to assign colors to individual points
           plot 'data' using 1:2:3 with points lc variable

           # A single data file may contain multiple sets of data, separated by two
           # blank lines.  Each data set is assigned as index value (see *note index::)
           # that can be retrieved via the *note using:: specifier `column(-2)`.
           # See `pseudocolumns`.  This example uses to value in column -2 to
           # draw each data set in a different line color.
           plot 'data' using 1:2:(column(-2)) with lines lc variable


File: gnuplot.info,  Node: rgbcolor_variable,  Prev: linecolor_variable,  Up: colorspec

1.17.1.3 rgbcolor variable
..........................

You can assign a separate color for each data point, line segment, or
label in your plot.  `lc rgbcolor variable` tells the program to read
RGB color information for each line in the data file. This requires a
corresponding additional column in the *note using:: specifier.  The
extra column is interpreted as a 24-bit packed RGB triple. If the value
is provided directly in the data file it is easiest to give it as a
hexidecimal value (see `rgbcolor`).  Alternatively, the *note using::
specifier can contain an expression that evaluates to a 24-bit RGB
color as in the example below.  Text colors are similarly set using `tc
rgbcolor variable`.

   Example:
           # Place colored points in 3D at the x,y,z coordinates corresponding to
           # their red, green, and blue components
           rgb(r,g,b) = 65536 * int(r) + 256 * int(g) + int(b)
           splot "data" using 1:2:3:(rgb($1,$2,$3)) with points lc rgb variable


File: gnuplot.info,  Node: linestyles_vs_linetypes,  Prev: colorspec,  Up: linetypes

1.17.2 linestyles vs linetypes
------------------------------

Lines can have additional properties such as linewidth.  You can
associate these various properties, as well as equivalent properties
for point symbols, into user-defined "linestyles" using the command
`set style line`.  Once you have defined a linestyle, you can use it in
a plot command to control the appearance of one or more plot elements.

   Whereas `linetypes` are permanent (they last until you explicitly
redefine them), `linestyles` are temporary.  They only last until the
next reset of the graphics state.

   Examples:

          # define a new line style with terminal-independent color cyan,
          # linewidth 3, and associated point type 6 (a circle with a dot in it).
          set style line 5 lt rgb "cyan" lw 3 pt 6
          plot sin(x) with linespoints ls 5          # user-defined line style 5


File: gnuplot.info,  Node: mouse_input,  Next: Plotting,  Prev: linetypes,  Up: gnuplot

1.18 mouse input
================

Many terminals allow interaction with the current plot using the mouse.
Some also support the definition of hotkeys to activate pre-defined
functions by hitting a single key while the mouse focus is in the
active plot window.  It is even possible to combine mouse input with
`batch` command scripts, by invoking the command `pause mouse` and then
using the mouse variables returned by mouse clicking as parameters for
subsequent scripted actions.  See `bind` and *note variables::.  See
also the command `set mouse`.

* Menu:

* bind::
* Mouse_variables::


File: gnuplot.info,  Node: bind,  Next: Mouse_variables,  Prev: mouse_input,  Up: mouse_input

1.18.1 bind
-----------

Syntax:
           bind {allwindows} [<key-sequence>] ["<gnuplot commands>"]
           bind <key-sequence> ""
           reset bind

   The `bind` allows defining or redefining a hotkey, i.e. a sequence
of gnuplot commands which will be executed when a certain key or key
sequence is pressed while the driver's window has the input focus. Note
that `bind` is only available if gnuplot was compiled with `mouse`
support and it is used by all mouse-capable terminals. A user-specified
binding supersedes any builtin bindings, except that <space> and 'q'
cannot normally be rebound. For an exception, see `bind space`.

   Mouse buttons cannot be rebound.

   You get the list of all hotkeys by typing `show bind` or `bind` or
by typing the hotkey 'h' in the graph window.

   Key bindings are restored to their default state by `reset bind`.

   Note that multikey-bindings with modifiers must be given in quotes.

   Normally hotkeys are only recognized when the currently active plot
window has focus. `bind allwindows <key> ...` (short form: `bind all
<key> ...`) causes the binding for <key> to apply to all gnuplot plot
windows, active or not.  In this case gnuplot variable MOUSE_KEY_WINDOW
is set to the ID of the originating window, and may be used by the
bound command.

   Examples:

   - set bindings:

         bind a "replot"
         bind "ctrl-a" "plot x*x"
         bind "ctrl-alt-a" 'print "great"'
         bind Home "set view 60,30; replot"
         bind all Home 'print "This is window ",MOUSE_KEY_WINDOW'

   - show bindings:
         bind "ctrl-a"          # shows the binding for ctrl-a
         bind                   # shows all bindings
         show bind              # show all bindings

   - remove bindings:
         bind "ctrl-alt-a" ""   # removes binding for ctrl-alt-a
                                  (note that builtins cannot be removed)
         reset bind             # installs default (builtin) bindings
         bind!                  # deprecated form of "reset bind"

   - bind a key to toggle something:
       v=0
       bind "ctrl-r" "v=v+1;if(v%2)set term x11 noraise; else set term x11 raise"

   Modifiers (ctrl / alt) are case insensitive, keys not:
         ctrl-alt-a == CtRl-alT-a
         ctrl-alt-a != ctrl-alt-A

   List of modifiers (alt == meta):
         ctrl, alt

   List of supported special keys:

        "BackSpace", "Tab", "Linefeed", "Clear", "Return", "Pause", "Scroll_Lock",
        "Sys_Req", "Escape", "Delete", "Home", "Left", "Up", "Right", "Down",
        "PageUp", "PageDown", "End", "Begin",

        "KP_Space", "KP_Tab", "KP_Enter", "KP_F1", "KP_F2", "KP_F3", "KP_F4",
        "KP_Home", "KP_Left", "KP_Up", "KP_Right", "KP_Down", "KP_PageUp",
        "KP_PageDown", "KP_End", "KP_Begin", "KP_Insert", "KP_Delete", "KP_Equal",
        "KP_Multiply", "KP_Add", "KP_Separator", "KP_Subtract", "KP_Decimal",
        "KP_Divide",

        "KP_1" - "KP_9", "F1" - "F12"

   The following are window events rather than actual keys

        "Close"

   See also help for `mouse`.

* Menu:

* bind_space::


File: gnuplot.info,  Node: bind_space,  Prev: bind,  Up: bind

1.18.1.1 bind space
...................

If gnuplot was built with configuration option -enable-raise-console,
then typing <space> in the plot window raises gnuplot's command window.
This hotkey can be changed to ctrl-space by starting gnuplot as
'gnuplot -ctrlq', or by setting the XResource 'gnuplot*ctrlq'.  See
`x11 command-line-options`.


File: gnuplot.info,  Node: Mouse_variables,  Prev: bind,  Up: mouse_input

1.18.2 Mouse variables
----------------------

When `mousing` is active, clicking in the active window will set
several user variables that can be accessed from the gnuplot command
line. The coordinates of the mouse at the time of the click are stored
in MOUSE_X MOUSE_Y MOUSE_X2 and MOUSE_Y2. The mouse button clicked, and
any meta-keys active at that time, are stored in MOUSE_BUTTON
MOUSE_SHIFT MOUSE_ALT and MOUSE_CTRL.  These variables are set to
undefined at the start of every plot, and only become defined in the
event of a mouse click in the active plot window. To determine from a
script if the mouse has been clicked in the active plot window, it is
sufficient to test for any one of these variables being defined.

           plot 'something'
           pause mouse
           if (defined(MOUSE_BUTTON)) call 'something_else'; \
           else print "No mouse click."

   It is also possible to track keystrokes in the plot window using the
mousing code.

           plot 'something'
           pause mouse keypress
           print "Keystroke ", MOUSE_KEY, " at ", MOUSE_X, " ", MOUSE_Y

   When `pause mouse keypress` is terminated by a keypress, then
MOUSE_KEY will contain the ascii character value of the key that was
pressed. MOUSE_CHAR will contain the character itself as a string
variable.  If the pause command is terminated abnormally (e.g. by
ctrl-C or by externally closing the plot window) then MOUSE_KEY will
equal -1.

   Note that after a zoom by mouse, you can read the new ranges as
GPVAL_X_MIN, GPVAL_X_MAX, GPVAL_Y_MIN, and GPVAL_Y_MAX, see *note
variables::.


File: gnuplot.info,  Node: Plotting,  Next: Start-up_(initialization),  Prev: mouse_input,  Up: gnuplot

1.19 Plotting
=============

There are three `gnuplot` commands which actually create a plot: `plot`,
`splot` and *note replot::.  `plot` generates 2D plots, `splot`
generates 3D plots (actually 2D projections, of course), and *note
replot:: appends its arguments to the previous `plot` or `splot` and
executes the modified command.

   Much of the general information about plotting can be found in the
discussion of `plot`; information specific to 3D can be found in the
`splot` section.

   `plot` operates in either rectangular or polar coordinates - see
`set polar` for details of the latter.  `splot` operates only in
rectangular coordinates, but the *note mapping:: command allows for a
few other coordinate systems to be treated.  In addition, the *note
using:: option allows both `plot` and `splot` to treat almost any
coordinate system you'd care to define.

   `plot` also lets you use each of the four borders - x (bottom), x2
(top), y (left) and y2 (right) - as an independent axis.  The *note
axes:: option lets you choose which pair of axes a given function or
data set is plotted against.  A full complement of `set` commands
exists to give you complete control over the scales and labelling of
each axis.  Some commands have the name of an axis built into their
names, such as *note xlabel::.  Other commands have one or more axis
names as options, such as `set logscale xy`.  Commands and options
controlling the z axis have no effect on 2D graphs.

   `splot` can plot surfaces and contours in addition to points and/or
lines.  See *note isosamples:: for information about defining the grid
for a 3D function.  See *note datafile:: for information about the
requisite file structure for 3D data values, *note contour:: and *note
cntrparam:: for information about contours.

   In `splot`, control over the scales and labels of the axes are the
same as with `plot`, except that commands and options controlling the
x2 and y2 axes have no effect whereas of course those controlling the z
axis do take effect.


File: gnuplot.info,  Node: Start-up_(initialization),  Next: String_constants_and_string_variables,  Prev: Plotting,  Up: gnuplot

1.20 Start-up (initialization)
==============================

When gnuplot is run, it first looks for a system-wide initialization
file named `gnuplotrc`.  The location of this file is determined when
the program is built and is reported by *note loadpath::.  The program
then looks in the user's HOME directory for a file called `.gnuplot` on
Unix-like systems or `GNUPLOT.INI` on other systems.  (Windows and OS/2
will look for it in the directory named in the environment variable
`GNUPLOT`; Windows will use `USERPROFILE` if GNUPLOT is not defined).
Note: The program can be configured to look first in the current
directory, but this is not recommended because it is bad security
practice.


File: gnuplot.info,  Node: String_constants_and_string_variables,  Next: Substitution_and_Command_line_macros,  Prev: Start-up_(initialization),  Up: gnuplot

1.21 String constants and string variables
==========================================

In addition to string constants, most gnuplot commands also accept a
string variable, a string expression, or a function that returns a
string.  For example, the following four methods of creating a plot all
result in the same plot title:

           four = "4"
           graph4 = "Title for plot #4"
           graph(n) = sprintf("Title for plot #%d",n)

           plot 'data.4' title "Title for plot #4"
           plot 'data.4' title graph4
           plot 'data.4' title "Title for plot #".four
           plot 'data.4' title graph(4)

   Since integers are promoted to strings when operated on by the string
concatenation operator, the following method also works:

           N = 4
           plot 'data.'.N title "Title for plot #".N

   In general, elements on the command line will only be evaluated as
possible string variables if they are not otherwise recognizable as
part of the normal gnuplot syntax. So the following sequence of
commands is legal, although probably should be avoided so as not to
cause confusion:

           plot = "my_datafile.dat"
           title = "My Title"
           plot plot title title

   There are three binary operators that require string operands: the
string concatenation operator ".", the string equality operator "eq"
and the string inequality operator "ne".  The following example will
print TRUE.

          if ("A"."B" eq "AB") print "TRUE"

   See also the two string formatting functions *note gprintf:: and
*note sprintf::.

   Substrings can be specified by appending a range specifier to any
string, string variable, or string-valued function.  The range
specifier has the form [begin:end], where begin is the index of the
first character of the substring and end is the index of the last
character of the substring.  The first character has index 1.  The
begin or end fields may be empty, or contain '*', to indicate the true
start or end of the original string.  E.g.  str[:] and str[*:*] both
describe the full string str.


File: gnuplot.info,  Node: Substitution_and_Command_line_macros,  Next: Syntax,  Prev: String_constants_and_string_variables,  Up: gnuplot

1.22 Substitution and Command line macros
=========================================

When a command line to gnuplot is first read, i.e. before it is
interpreted or executed, two forms of lexical substitution are
performed. These are triggered by the presence of text in backquotes
(ascii character 96) or preceded by @ (ascii character 64).

* Menu:

* Substitution_of_system_commands_in_backquotes::
* Substitution_of_string_variables_as_macros::
* String_variables::


File: gnuplot.info,  Node: Substitution_of_system_commands_in_backquotes,  Next: Substitution_of_string_variables_as_macros,  Prev: Substitution_and_Command_line_macros,  Up: Substitution_and_Command_line_macros

1.22.1 Substitution of system commands in backquotes
----------------------------------------------------

Command-line substitution is specified by a system command enclosed in
backquotes.  This command is spawned and the output it produces replaces
the backquoted text on the command line.  Some implementations also
support pipes;  see *note special-filenames::.

   Command-line substitution can be used anywhere on the `gnuplot`
command line, except inside strings delimited by single quotes.

   Example:

   This will run the program `leastsq` and replace `leastsq` (including
backquotes) on the command line with its output:
           f(x) = `leastsq`

   or, in VMS
           f(x) = `run leastsq`

   These will generate labels with the current time and userid:
           set label "generated on `date +%Y-%m-%d` by `whoami`" at 1,1
           set timestamp "generated on %Y-%m-%d by `whoami`"


File: gnuplot.info,  Node: Substitution_of_string_variables_as_macros,  Next: String_variables,  Prev: Substitution_of_system_commands_in_backquotes,  Up: Substitution_and_Command_line_macros

1.22.2 Substitution of string variables as macros
-------------------------------------------------

Substitution of command line macros is disabled by default, but may be
enabled using the *note macros:: command.  If macro substitution is
enabled, the character @ is used to trigger substitution of the current
value of a string variable into the command line. The text in the
string variable may contain any number of lexical elements.  This
allows string variables to be used as command line macros.  Only string
constants may be expanded using this mechanism, not string-valued
expressions.  For example:

           set macros
           style1 = "lines lt 4 lw 2"
           style2 = "points lt 3 pt 5 ps 2"
           range1 = "using 1:3"
           range2 = "using 1:5"
           plot "foo" @range1 with @style1, "bar" @range2 with @style2

   The line containing @ symbols is expanded on input, so that by the
time it is executed the effect is identical to having typed in full

           plot "foo" using 1:3 with lines lt 4 lw 2, \
                "bar" using 1:5 with points lt 3 pt 5 ps 2

   The function exists() may be useful in connection with macro
evaluation.  The following example checks that C can safely be expanded
as the name of a user-defined variable:

           C = "pi"
           if (exists(C)) print C," = ", @C

   Macro expansion does not occur inside either single or double quotes.
However macro expansion does occur inside backquotes.

   Macro expansion is handled as the very first thing the interpreter
does when looking at a new line of commands and is only done once.
Therefore, code like the following will execute correctly:

          A = "c=1"
          @A

   but this line will not, since the macro is defined on the same line
and will not be expanded in time

          A = "c=1"; @A   # will not expand to c=1

   For execution of complete commands the *note evaluate:: command may
also be handy.


File: gnuplot.info,  Node: String_variables,  Prev: Substitution_of_string_variables_as_macros,  Up: Substitution_and_Command_line_macros

1.22.3 String variables, macros, and command line substitution
--------------------------------------------------------------

The interaction of string variables, backquotes and macro substitution
is somewhat complicated.  Backquotes do not block macro substitution, so

           filename = "mydata.inp"
           lines = ` wc --lines @filename | sed "s/ .*//" `

   results in the number of lines in mydata.inp being stored in the
integer variable lines. And double quotes do not block backquote
substitution, so

           mycomputer = "`uname -n`"

   results in the string returned by the system command `uname -n`
being stored in the string variable mycomputer.

   However, macro substitution is not performed inside double quotes,
so you cannot define a system command as a macro and then use both
macro and backquote substitution at the same time.

            machine_id = "uname -n"
            mycomputer = "`@machine_id`"  # doesn't work!!

   This fails because the double quotes prevent @machine_id from being
interpreted as a macro. To store a system command as a macro and
execute it later you must instead include the backquotes as part of the
macro itself.  This is accomplished by defining the macro as shown
below.  Notice that the sprintf format nests all three types of quotes.

           machine_id = sprintf('"`uname -n`"')
           mycomputer = @machine_id


File: gnuplot.info,  Node: Syntax,  Next: Time/Date_data,  Prev: Substitution_and_Command_line_macros,  Up: gnuplot

1.23 Syntax
===========

Options and any accompanying parameters are separated by spaces whereas
lists and coordinates are separated by commas.  Ranges are separated by
colons and enclosed in brackets [], text and file names are enclosed in
quotes, and a few miscellaneous things are enclosed in parentheses.

   Commas are used to separate coordinates on the `set` commands *note
arrow::, `key`, and `label`; the list of variables being fitted (the
list after the `via` keyword on the *note fit:: command); lists of
discrete contours or the loop parameters which specify them on the
*note cntrparam:: command; the arguments of the `set` commands *note
dgrid3d::, *note dummy::, *note isosamples::, *note offsets::, *note
origin::, *note samples::, *note size::, `time`, and *note view::;
lists of tics or the loop parameters which specify them; the offsets
for titles and axis labels; parametric functions to be used to
calculate the x, y, and z coordinates on the `plot`, *note replot:: and
`splot` commands; and the complete sets of keywords specifying
individual plots (data sets or functions) on the `plot`, *note replot::
and `splot` commands.

   Parentheses are used to delimit sets of explicit tics (as opposed to
loop parameters) and to indicate computations in the *note using::
filter of the *note fit::, `plot`, *note replot:: and `splot` commands.

   (Parentheses and commas are also used as usual in function notation.)

   Square brackets are used to delimit ranges given in `set`, `plot` or
`splot` commands.

   Colons are used to separate extrema in `range` specifications
(whether they are given on `set`, `plot` or `splot` commands) and to
separate entries in the *note using:: filter of the `plot`, *note
replot::, `splot` and *note fit:: commands.

   Semicolons are used to separate commands given on a single command
line.

   Curly braces are used in the syntax for enhanced text mode and to
delimit blocks in if/then/else statements.  They are also used to
denote complex numbers: {3,2} = 3 + 2i.

   The EEPIC, Imagen, Uniplex, LaTeX, and TPIC drivers allow a newline
to be specified by \\ in a single-quoted string or \\\\ in a
double-quoted string.

* Menu:

* Quote_Marks::


File: gnuplot.info,  Node: Quote_Marks,  Prev: Syntax,  Up: Syntax

1.23.1 Quote Marks
------------------

Gnuplot uses three forms of quote marks for delimiting text strings,
double-quote (ascii 34), single-quote (ascii 39), and backquote (ascii
96).

   Filenames may be entered with either single- or double-quotes.  In
this manual the command examples generally single-quote filenames and
double-quote other string tokens for clarity.

   String constants and text strings used for labels, titles, or other
plot elements may be enclosed in either single quotes or double quotes.
Further processing of the quoted text depends on the choice of quote
marks.

   Backslash processing of special characters like \n (newline) and
\345 (octal character code) is performed for double-quoted strings.  In
single-quoted strings, backslashes are just ordinary characters.  To get
a single-quote (ascii 39) in a single-quoted string, it has to be
doubled.  Thus the strings "d\" s' b\\" and 'd" s" b\' are completely
equivalent.

   Text justification is the same for each line of a multi-line string.
Thus the center-justified string
           "This is the first line of text.\nThis is the second line."

   will produce
                            This is the first line of text.
                               This is the second line.

   but
           'This is the first line of text.\nThis is the second line.'

   will produce
               This is the first line of text.\nThis is the second line.

   Enhanced text processing is performed for both double-quoted text and
single-quoted text, but only by terminals supporting this mode.  See
`enhanced text`.

   Back-quotes are used to enclose system commands for substitution
into the command line.  See `substitution`.


File: gnuplot.info,  Node: Time/Date_data,  Prev: Syntax,  Up: gnuplot

1.24 Time/Date data
===================

`gnuplot` supports the use of time and/or date information as input
data.  This feature is activated by the commands `set xdata time`, `set
ydata time`, etc.

   Internally all times and dates are converted to the number of
seconds from the year 2000.  The command *note timefmt:: defines the
format for all inputs: data files, ranges, tics, label positions--in
short, anything that accepts a data value must receive it in this
format.  Since only one input format can be in force at a given time,
all time/date quantities being input at the same time must be presented
in the same format.  Thus if both x and y data in a file are time/date,
they must be in the same format.

   The conversion to and from seconds assumes Universal Time (which is
the same as Greenwich Standard Time).  There is no provision for
changing the time zone or for daylight savings.  If all your data refer
to the same time zone (and are all either daylight or standard) you
don't need to worry about these things.  But if the absolute time is
crucial for your application, you'll need to convert to UT yourself.

   Commands like *note xrange:: will re-interpret the integer according
to *note timefmt::.  If you change *note timefmt::, and then `show` the
quantity again, it will be displayed in the new *note timefmt::.  For
that matter, if you give the deactivation command (like *note xdata::),
the quantity will be shown in its numerical form.

   The commands `set format` or `set tics format` define the format
that will be used for tic labels, whether or not the specified axis is
time/date.

   If time/date information is to be plotted from a file, the *note
using:: option _must_ be used on the `plot` or `splot` command.  These
commands simply use white space to separate columns, but white space
may be embedded within the time/date string.  If you use tabs as a
separator, some trial-and-error may be necessary to discover how your
system treats them.

   The `time` function can be used to get the current system time. This
value can be converted to a date string with the *note strftime::
function, or it can be used in conjunction with *note timecolumn:: to
generate relative time/date plots.  The type of the argument determines
what is returned. If the argument is an integer, `time` returns the
current time as an integer, in seconds from 1 Jan 2000. If the argument
is real (or complex), the result is real as well.  The precision of the
fractional (sub-second) part depends on your operating system. If the
argument is a string, it is assumed to be a format string, and it is
passed to *note strftime:: to provide a formatted time/date string.

   The following example demonstrates time/date plotting.

   Suppose the file "data" contains records like

           03/21/95 10:00  6.02e23

   This file can be plotted by

           set xdata time
           set timefmt "%m/%d/%y"
           set xrange ["03/21/95":"03/22/95"]
           set format x "%m/%d"
           set timefmt "%m/%d/%y %H:%M"
           plot "data" using 1:3

   which will produce xtic labels that look like "03/21".

   See `time_specifiers`.


File: gnuplot.info,  Node: plotting_styles,  Next: Commands,  Prev: gnuplot,  Up: Top

2 plotting styles
*****************

There are many plotting styles available in gnuplot.  They are listed
alphabetically below.  The commands `set style data` and `set style
function` change the default plotting style for subsequent `plot` and
`splot` commands.

   You also have the option to specify the plot style explicitly as
part of the `plot` or `splot` command.  If you want to mix plot styles
within a single plot, you must specify the plot style for each
component.

   Example:

          plot 'data' with boxes, sin(x) with lines

   Each plot style has its own expected set of data entries in a data
file.  For example by default the `lines` style expects either a single
column of y values (with implicit x ordering) or a pair of columns with
x in the first and y in the second.  For more information on how to
fine-tune how columns in a file are interpreted as plot data, see *note
using::.

* Menu:

* boxerrorbars::
* boxes::
* boxplot::
* boxxyerrorbars::
* candlesticks::
* circles::
* ellipses::
* dots::
* filledcurves::
* financebars::
* fsteps::
* fillsteps::
* histeps::
* histograms::
* image::
* impulses::
* labels::
* lines::
* linespoints::
* points::
* polar::
* steps::
* rgbalpha::
* rgbimage::
* vectors::
* xerrorbars::
* xyerrorbars::
* yerrorbars::
* xerrorlines::
* xyerrorlines::
* yerrorlines::
* 3D_(surface)_plots::


File: gnuplot.info,  Node: boxerrorbars,  Next: boxes,  Prev: plotting_styles,  Up: plotting_styles

2.1 boxerrorbars
================

The *note boxerrorbars:: style is only relevant to 2D data plotting.
It is a combination of the *note boxes:: and *note yerrorbars:: styles.
It uses 3, 4, or 5 columns of data:

          3 columns:  x  y  ydelta
          4 columns:  x  y  ydelta xdelta        # boxwidth != -2
          4 columns:  x  y  ylow  yhigh          # boxwidth == -2
          5 columns:  x  y  ylow  yhigh  xdelta

   The boxwidth will come from the fourth column if the y errors are
given as "ydelta" and the boxwidth was not previously set to -2.0 (`set
boxwidth -2.0`) or from the fifth column if the y errors are in the
form of "ylow yhigh".  The special case  `boxwidth = -2.0` is for
four-column data with y errors in the form "ylow yhigh".  In this case
the boxwidth will be calculated so that each box touches the adjacent
boxes.  The width will also be calculated in cases where three-column
data are used.

   An additional (4th, 5th or 6th) input column may be used to provide
variable (per-datapoint) color information (see `linecolor` and
`rgbcolor variable`).  The error bar will be drawn in the same color as
the border of the box.

   The box height is determined from the y error in the same way as it
is for the *note yerrorbars:: style--either from y-ydelta to y+ydelta
or from ylow to yhigh, depending on how many data columns are provided.
See also errorbar demo. (http://www.gnuplot.info/demo/mgr.html)


File: gnuplot.info,  Node: boxes,  Next: boxplot,  Prev: boxerrorbars,  Up: plotting_styles

2.2 boxes
=========

The *note boxes:: style is only relevant to 2D plotting.  It draws a
box centered about the given x coordinate that extends from the x axis
(not from the graph border) to the given y coordinate.  It uses 2 or 3
columns of basic data.  Additional input columns may be used to provide
information such as variable line or fill color (see `rgbcolor
variable`).

          2 columns:  x  y
          3 columns:  x  y  x_width

   The width of the box is obtained in one of three ways.  If the input
data has a third column, this will be used to set the width of the box.
If not, if a width has been set using the *note boxwidth:: command,
this will be used.  If neither of these is available, the width of each
box will be calculated automatically so that it touches the adjacent
boxes.

   The interior of the boxes is drawn according to the current
fillstyle.  See `set style fill` for details.  Alternatively a new
fillstyle may be specified in the plot command.

   For fillstyle `empty` the box is not filled.

   For fillstyle `solid` the box is filled with a solid rectangle of the
current drawing color. There is an optional parameter <density> that
controls the fill density; it runs from 0 (background color) to 1
(current drawing color).

   For fillstyle `pattern` the box is filled in the current drawing
color with a pattern, if supported by the terminal driver.

   Examples:

   To plot a data file with solid filled boxes with a small vertical
space separating them (bargraph):

           set boxwidth 0.9 relative
           set style fill solid 1.0
           plot 'file.dat' with boxes

   To plot a sine and a cosine curve in pattern-filled boxes style:

           set style fill pattern
           plot sin(x) with boxes, cos(x) with boxes

   The sin plot will use pattern 0; the cos plot will use pattern 1.
Any additional plots would cycle through the patterns supported by the
terminal driver.

   To specify explicit fillstyles for each dataset:

          plot 'file1' with boxes fs solid 0.25, \
               'file2' with boxes fs solid 0.50, \
               'file3' with boxes fs solid 0.75, \
               'file4' with boxes fill pattern 1, \
               'file5' with boxes fill empty


File: gnuplot.info,  Node: boxplot,  Next: boxxyerrorbars,  Prev: boxes,  Up: plotting_styles

2.3 boxplot
===========

Boxplots are a common way to represent a statistical distribution of
values.  Quartile boundaries are determined such that 1/4 of the points
have a value equal or less than the first quartile boundary, 1/2 of the
points have a value equal or less than the second quartile (median)
value, etc.  A box is drawn around the region between the first and
third quartiles, with a horizontal line at the median value.  Whiskers
extend from the box to user-specified limits.  Points that lie outside
these limits are drawn individually.

   Examples

         # Place a boxplot at x coordinate 1.0 representing the y values in column 5
         plot 'data' using (1.0):5

         # Same plot but suppress outliers and force the width of the boxplot to 0.3
         set style boxplot nooutliers
         plot 'data' using (1.0):5:(0.3)

   By default only one boxplot is produced that represents all y values
from the second column of the using specification. However, an
additional (fourth) colunm can be added to the specification. If
present, the values of that column will be interpreted as the discrete
levels of a factor variable.  As many boxplots will be drawn as there
are levels in the factor variable.  The separation between these
boxplots is 1.0 by default, but it can be changed by `set style boxplot
separation`. By default, the value of the factor variable is shown as a
tic label below (or above) each boxplot.

   Example

         # Suppose that column 2 of 'data' contains either "control" or "treatment"
         # The following example produces two boxplots, one for each level of the
         # factor
         plot 'data' using (1.0):5:(0):2

   The default width of the box can be set via `set boxwidth <width>`
or may be specified as an optional 3rd column in the *note using::
clause of the plot command.  The first and third columns (x coordinate
and width) are normally provided as constants rather than as data
columns.

   By default the whiskers extend from the ends of the box to the most
distant point whose y value lies within 1.5 times the interquartile
range. By default outliers are drawn as circles (point type 7).  The
width of the bars at the end of the whiskers may be controlled using
*note bars::.

   These default properties may be changed using the *note boxplot::
command.  See *note boxplot::, *note bars::, *note boxwidth::,
`fillstyle`, *note candlesticks::.


File: gnuplot.info,  Node: boxxyerrorbars,  Next: candlesticks,  Prev: boxplot,  Up: plotting_styles

2.4 boxxyerrorbars
==================

The *note boxxyerrorbars:: style is only relevant to 2D data plotting.
It is similar to the *note xyerrorbars:: style except that it draws
rectangular areas rather than simple crosses.  It uses either 4 or 6
basic columns of input data.  Additional input columns may be used to
provide information such as variable line or fill color (see `rgbcolor
variable`).

          4 columns:  x  y  xdelta  ydelta
          6 columns:  x  y  xlow  xhigh  ylow  yhigh

   The box width and height are determined from the x and y errors in
the same way as they are for the *note xyerrorbars:: style--either from
xlow to xhigh and from ylow to yhigh, or from x-xdelta to x+xdelta and
from y-ydelta to y+ydelta, depending on how many data columns are
provided.

   An additional (5th or 7th) input column may be used to provide
variable (per-datapoint) color information (see `linecolor` and
`rgbcolor variable`).

   The interior of the boxes is drawn according to the current
fillstyle.  See `set style fill` and *note boxes:: for details.
Alternatively a new fillstyle may be specified in the plot command.


File: gnuplot.info,  Node: candlesticks,  Next: circles,  Prev: boxxyerrorbars,  Up: plotting_styles

2.5 candlesticks
================

The *note candlesticks:: style can be used for 2D data plotting of
financial data or for generating box-and-whisker plots of statistical
data.  The symbol is a rectangular box, centered horizontally at the x
coordinate and limited vertically by the opening and closing prices.  A
vertical line segment at the x coordinate extends up from the top of the
rectangle to the high price and another down to the low.  The vertical
line will be unchanged if the low and high prices are interchanged.

   Five columns of basic data are required:

           financial data:   date  open  low  high  close
           whisker plot:     x  box_min  whisker_min  whisker_high  box_high

   The width of the rectangle can be controlled by the *note boxwidth::
command.  For backwards compatibility with earlier gnuplot versions,
when the boxwidth parameter has not been set then the width of the
candlestick rectangle is controlled by `set bars <width>`.

   Alternatively, an explicit width for each box-and-whiskers grouping
may be specified in an optional 6th column of data.  The width must be
given in the same units as the x coordinate.

   An additional (6th, or 7th if the 6th column is used for width data)
input column may be used to provide variable (per-datapoint) color
information (see `linecolor` and `rgbcolor variable`).

   By default the vertical line segments have no crossbars at the top
and bottom. If you want crossbars, which are typically used for
box-and-whisker plots, then add the keyword `whiskerbars` to the plot
command.  By default these whiskerbars extend the full horizontal width
of the candlestick, but you can modify this by specifying a fraction of
the full width.

   The usual convention for financial data is that the rectangle is
empty if (open < close) and solid fill if (close < open). This is the
behavior you will get if the current fillstyle is set to "empty". See
`fillstyle`.  If you set the fillstyle to solid or pattern, then this
will be used for all boxes independent of open and close values.  See
also *note bars:: and *note financebars::.  See also the candlestick
(http://www.gnuplot.info/demo/candlesticks.html) and finance
(http://www.gnuplot.info/demo/finance.html) demos.

   Note: To place additional symbols, such as the median value, on a
box-and-whisker plot requires additional plot commands as in this
example:

       # Data columns:X Min 1stQuartile Median 3rdQuartile Max
       set bars 4.0
       set style fill empty
       plot 'stat.dat' using 1:3:2:6:5 with candlesticks title 'Quartiles', \
            ''         using 1:4:4:4:4 with candlesticks lt -1 notitle

       # Plot with crossbars on the whiskers, crossbars are 50% of full width
       plot 'stat.dat' using 1:3:2:6:5 with candlesticks whiskerbars 0.5

   See *note boxwidth::, *note bars::, `set style fill`, and *note
boxplot::.


File: gnuplot.info,  Node: circles,  Next: ellipses,  Prev: candlesticks,  Up: plotting_styles

2.6 circles
===========

The *note circles:: style plots a circle with an explicit radius at
each data point.  If three columns of data are present, they are
interpreted as x, y, radius.  The radius is always interpreted in the
units of the plot's horizontal axis (x or x2).  The scale on y and the
aspect ratio of the plot are both ignored.  If only two columns are
present, the radius is taken from `set style circle`.  In this case the
radius may be given in graph or screen coordinates.  By default a full
circle will be drawn.  It is possible to plot arc segments instead of
full circles by specifying a start and end angle in the 4th and 5th
columns.  An optional 4th or 6th column can specify per-circle color.
The start and end angles of the circle segments must be specified in
degrees.

   Examples:

         # draws circles whose area is proportional to the value in column 3
         set style fill transparent solid 0.2 noborder
         plot 'data' using 1:2:(sqrt($3)) with circles, \
              'data' using 1:2 with linespoints

         # draws Pac-men instead of circles
         plot 'data' using 1:2:(10):(40):(320) with circles

         # draw a pie chart with inline data
         set xrange [-15:15]
         set style fill transparent solid 0.9 noborder
         plot '-' using 1:2:3:4:5:6 with circles lc var
         0    0    5    0    30    1
         0    0    5   30    70    2
         0    0    5   70   120    3
         0    0    5  120   230    4
         0    0    5  230   360    5
         e

   The result is similar to using a `points` plot with variable size
points and pointstyle 7, except that the circles will scale with the x
axis range.  See also `set object circle` and `fillstyle`.


File: gnuplot.info,  Node: ellipses,  Next: dots,  Prev: circles,  Up: plotting_styles

2.7 ellipses
============

The *note ellipses:: style plots an ellipse at each data point.  This
style is only relevant for 2D plotting.  Each ellipse is described in
terms of its center, major and minor diameters, and the angle between
its major diameter and the x axis.

          2 columns: x y
          3 columns: x y major_diam
          4 columns: x y major_diam minor_diam
          5 columns: x y major_diam minor_diam angle

   If only two input columns are present, they are taken as the
coordinates of the centers, and the ellipses will be drawn with the
default extent (see `set style ellipse`).  The orientation of the
ellipse, which is defined as the angle between the major diameter and
the plot's x axis, is taken from the default ellipse style (see `set
style ellipse`).  If three input columns are provided, the third column
is used for both diameters.  The orientation angle defaults to zero.
If four columns are present, they are interpreted as x, y, major
diameter, minor diameter.  Note that these are diameters, not radii.
An optional 5th column may be used to specify the orientation angle in
degrees.  The ellipses will also be drawn with their default extent if
either of the supplied diameters in the 3-4-5 column form is negative.

   In all of the above cases, optional variable color data may be given
in an additional last (3th, 4th, 5th or 6th) column. See *note
colorspec:: for further information.

   By default, the major diameter is interpreted in the units of the
plot's horizontal axis (x or x2) while the minor diameter in that of
the vertical (y or y2).  This implies that if the x and y axis scales
are not equal, then the major/minor diameter ratio will no longer be
correct after rotation.  This behavior can be changed with the `units`
keyword, however.

   There are three alternatives: if `units xy` is included in the plot
specification, the axes will be scaled as described above. `units xx`
ensures that both diameters are interpreted in units of the x axis,
while `units yy` means that both diameters are interpreted in units of
the y axis. In the latter two cases the ellipses will have the correct
aspect ratio, even if the plot is resized.

   If `units` is omitted, the default setting will be used, which is
equivalent to `units xy`. This can be redefined by `set style ellipse`.

   Example (draws ellipses, cycling through the available line types):

         plot 'data' using 1:2:3:4:(0):0 with ellipses

   See also `set object ellipse`, `set style ellipse` and `fillstyle`.


File: gnuplot.info,  Node: dots,  Next: filledcurves,  Prev: ellipses,  Up: plotting_styles

2.8 dots
========

The *note dots:: style plots a tiny dot at each point; this is useful
for scatter plots with many points.  Either 1 or 2 columns of input
data are required in 2D.  Three columns are required in 3D.

   For some terminals (post, pdf) the size of the dot can be controlled
by changing the linewidth.

          1 column    y         # x is row number
          2 columns:  x  y
          3 columns:  x  y  z   # 3D only (splot)


File: gnuplot.info,  Node: filledcurves,  Next: financebars,  Prev: dots,  Up: plotting_styles

2.9 filledcurves
================

The *note filledcurves:: style is only relevant to 2D plotting. Three
variants are possible. The first two variants require either a function
or two columns of input data, and may be further modified by the
options listed below.

   Syntax:

         plot ... with filledcurves [option]

   where the option can be one of the following

         [closed | {above | below}
         {x1 | x2 | y1 | y2 | r}[=<a>] | xy=<x>,<y>]

   The first variant, `closed`, treats the curve itself as a closed
polygon.  This is the default if there are two columns of input data.

   The second variant is to fill the area between the curve and a given
axis, a horizontal or vertical line, or a point.

         filledcurves closed   ... just filled closed curve,
         filledcurves x1       ... x1 axis,
         filledcurves x2       ... x2 axis, etc for y1 and y2 axes,
         filledcurves y1=0     ... line y=0 (at y1 axis) ie parallel to x1 axis,
         filledcurves y2=42    ... line y=42 (at y2 axis) ie parallel to x2, etc,
         filledcurves xy=10,20 ... point 10,20 of x1,y1 axes (arc-like shape).
         filledcurves above r=1.5  the area of a polar plot outside radius 1.5

   The third variant requires three columns of input data: the x
coordinate and two y coordinates corresponding to two curves sampled at
the same set of x coordinates; the area between the two curves is
filled.  This is the default if there are three or more columns of
input data.

          3 columns:  x  y1  y2

   Example of filling the area between two input curves.  fill between
curves demo. (http://www.gnuplot.info/demo/fillbetween.html)

         plot 'data' using 1:2:3 with filledcurves

   The `above` and `below` options apply both to commands of the form
         ... filledcurves above {x1|x2|y1|y2|r}=<val>

   and to commands of the form
         ... using 1:2:3 with filledcurves below

   In either case the option limits the filled area to one side of the
bounding line or curve.

   Note: Not all terminal types support this plotting mode.

   Zooming a filled curve drawn from a datafile may produce empty or
incorrect areas because gnuplot is clipping points and lines, and not
areas.

   If the values of <a>, <x>, <y> are out of the drawing boundary, then
they are moved to the graph boundary. Then the actually filled area in
the case of option xy=<x>,<y> will depend on xrange and yrange.


File: gnuplot.info,  Node: financebars,  Next: fsteps,  Prev: filledcurves,  Up: plotting_styles

2.10 financebars
================

The *note financebars:: style is only relevant for 2D data plotting of
financial data.  It requires 1 x coordinate (usually a date) and 4 y
values (prices).

          5 columns:   date  open  low  high  close

   An additional (6th) input column may be used to provide variable
(per-record) color information (see `linecolor` and `rgbcolor
variable`).

   The symbol is a vertical line segment, located horizontally at the x
coordinate and limited vertically by the high and low prices.  A
horizontal tic on the left marks the opening price and one on the right
marks the closing price.  The length of these tics may be changed by
*note bars::.  The symbol will be unchanged if the high and low prices
are interchanged.  See *note bars:: and *note candlesticks::, and also
the finance demo. (http://www.gnuplot.info/demo/finance.html)


File: gnuplot.info,  Node: fsteps,  Next: fillsteps,  Prev: financebars,  Up: plotting_styles

2.11 fsteps
===========

The *note fsteps:: style is only relevant to 2D plotting.  It connects
consecutive points with two line segments: the first from (x1,y1) to
(x1,y2) and the second from (x1,y2) to (x2,y2).  The input column
requires are the same as for plot styles `lines` and `points`.  The
difference between *note fsteps:: and *note steps:: is that *note
fsteps:: traces first the change in y and then the change in x.  *note
steps:: traces first the change in x and then the change in y.

   See also steps demo. (http://www.gnuplot.info/demo/steps.html)


File: gnuplot.info,  Node: fillsteps,  Next: histeps,  Prev: fsteps,  Up: plotting_styles

2.12 fillsteps
==============

The *note fillsteps:: style is exactly like *note steps:: except that
the area between the curve and y=0 is filled in the current fill style.
See *note steps::.


File: gnuplot.info,  Node: histeps,  Next: histograms,  Prev: fillsteps,  Up: plotting_styles

2.13 histeps
============

The *note histeps:: style is only relevant to 2D plotting.  It is
intended for plotting histograms.  Y-values are assumed to be centered
at the x-values; the point at x1 is represented as a horizontal line
from ((x0+x1)/2,y1) to ((x1+x2)/2,y1).  The lines representing the end
points are extended so that the step is centered on at x.  Adjacent
points are connected by a vertical line at their average x, that is,
from ((x1+x2)/2,y1) to ((x1+x2)/2,y2).  The input column requires are
the same as for plot styles `lines` and `points`.

   If *note autoscale:: is in effect, it selects the xrange from the
data rather than the steps, so the end points will appear only half as
wide as the others.  See also steps demo.
(http://www.gnuplot.info/demo/steps.html)

   *note histeps:: is only a plotting style; `gnuplot` does not have
the ability to create bins and determine their population from some
data set.


File: gnuplot.info,  Node: histograms,  Next: image,  Prev: histeps,  Up: plotting_styles

2.14 histograms
===============

The *note histograms:: style is only relevant to 2D plotting.  It
produces a bar chart from a sequence of parallel data columns. Each
element of the `plot` command must specify a single input data source
(e.g. one column of the input file), possibly with associated tic
values or key titles.  Four styles of histogram layout are currently
supported.

           set style histogram clustered {gap <gapsize>}
           set style histogram errorbars {gap <gapsize>} {<linewidth>}
           set style histogram rowstacked
           set style histogram columnstacked

   The default style corresponds to `set style histogram clustered gap
2`.  In this style, each set of parallel data values is collected into
a group of boxes clustered at the x-axis coordinate corresponding to
their sequential position (row #) in the selected datafile columns.
Thus if <n> datacolumns are selected, the first cluster is centered
about x=1, and contains <n> boxes whose heights are taken from the
first entry in the corresponding <n> data columns.  This is followed by
a gap and then a second cluster of boxes centered about x=2
corresponding to the second entry in the respective data columns, and
so on.  The default gap width of 2 indicates that the empty space
between clusters is equivalent to the width of 2 boxes.  All boxes
derived from any one column are given the same fill color and/or
pattern (see `set style fill`).

   Each cluster of boxes is derived from a single row of the input data
file.  It is common in such input files that the first element of each
row is a label. Labels from this column may be placed along the x-axis
underneath the appropriate cluster of boxes with the `xticlabels`
option to *note using::.

   The *note errorbars:: style is very similar to the `clustered`
style, except that it requires additional columns of input for each
entry. The first column holds the height (y value) of that box, exactly
as for the `clustered` style.
          2 columns:        y yerr          bar extends from y-yerr to y+err
          3 columns:        y ymin yman     bar extends from ymin to ymax

   The appearance of the error bars is controlled by the current value
of *note bars:: and by the optional <linewidth> specification.

   Two styles of stacked histogram are supported, chosen by the command
`set style histogram {rowstacked|columnstacked}`.  In these styles the
data values from the selected columns are collected into stacks of
boxes.  Positive values stack upwards from y=0; negative values stack
downwards.  Mixed positive and negative values will produce both an
upward stack and a downward stack.  The default stacking mode is
`rowstacked`.

   The `rowstacked` style places a box resting on the x-axis for each
data value in the first selected column; the first data value results in
a box a x=1, the second at x=2, and so on.  Boxes corresponding to the
second and subsequent data columns are layered on top of these,
resulting in a stack of boxes at x=1 representing the first data value
from each column, a stack of boxes at x=2 representing the second data
value from each column, and so on.  All boxes derived from any one
column are given the same fill color and/or pattern (see `set style
fill`).

   The `columnstacked` style is similar, except that each stack of
boxes is built up from a single data column. Each data value from the
first specified column yields a box in the stack at x=1, each data
value from the second specified column yields a box in the stack at
x=2, and so on.  In this style the color of each box is taken from the
row number, rather than the column number, of the corresponding data
field.

   Box widths may be modified using the *note boxwidth:: command.  Box
fill styles may be set using the `set style fill` command.

   Histograms always use the x1 axis, but may use either y1 or y2.  If
a plot contains both histograms and other plot styles, the non-histogram
plot elements may use either the x1 or the x2 axis.

   Examples: Suppose that the input file contains data values in
columns 2, 4, 6, ...  and error estimates in columns 3, 5, 7, ...  This
example plots the values in columns 2 and 4 as a histogram of clustered
boxes (the default style).  Because we use iteration in the plot
command, any number of data columns can be handled in a single command.
See *note iteration::.

           set boxwidth 0.9 relative
           set style data histograms
           set style histogram cluster
           set style fill solid 1.0 border lt -1
           plot for [COL=2:4:2] 'file.dat' using COL

   This will produce a plot with clusters of two boxes (vertical bars)
centered at each integral value on the x axis.  If the first column of
the input file contains labels, they may be placed along the x-axis
using the variant command

           plot for [COL=2:4:2] 'file.dat' using COL:xticlabels(1)

   If the file contains both magnitude and range information for each
value, then error bars can be added to the plot.  The following
commands will add error bars extending from (y-<error>) to (y+<error>),
capped by horizontal bar ends drawn the same width as the box itself.
The error bars and bar ends are drawn with linewidth 2, using the
border linetype from the current fill style.

           set bars fullwidth
           set style fill solid 1 border lt -1
           set style histogram errorbars gap 2 lw 2
           plot for [COL=2:4:2] 'file.dat' using COL:COL+1

   To plot the same data as a rowstacked histogram.  Just to be
different, this example lists the separate columns explicitly rather
than using iteration.

           set style histogram rowstacked
           plot 'file.dat' using 2, '' using 4:xtic(1)

   This will produce a plot in which each vertical bar corresponds to
one row of data.  Each vertical bar contains a stack of two segments,
corresponding in height to the values found in columns 2 and 4 of the
datafile.

   Finally, the commands

           set style histogram columnstacked
           plot 'file.dat' using 2, '' using 4

   will produce two vertical stacks, one for each column of data.  The
stack at x=1 will contain a box for each entry in column 2 of the
datafile.  The stack at x=2 will contain a box for each parallel entry
in column 4 of the datafile.  Because this interchanges gnuplot's usual
interpretation of input rows and columns, the specification of key
titles and x-axis tic labels must also be modified accordingly. See the
comments given below.

           set style histogram columnstacked
           plot '' u 5:key(1)            # uses first column to generate key titles
           plot '' u 5 title columnhead  # uses first row to generate xtic labels

   Note that the two examples just given present exactly the same data
values, but in different formats.

* Menu:

* newhistogram::
* automated_iteration_over_multiple_columns::


File: gnuplot.info,  Node: newhistogram,  Next: automated_iteration_over_multiple_columns,  Prev: histograms,  Up: histograms

2.14.1 newhistogram
-------------------

Syntax:

          newhistogram {"<title>"} {lt <linetype>} {fs <fillstyle>} {at <x-coord>}

   More than one set of histograms can appear in a single plot. In this
case you can force a gap between them, and a separate label for each
set, by using the *note newhistogram:: command.  For example

           set style histogram  cluster
           plot newhistogram "Set A", 'a' using 1, '' using 2, '' using 3, \
                newhistogram "Set B", 'b' using 1, '' using 2, '' using 3

   The labels "Set A" and "Set B" will appear beneath the respective
sets of histograms, under the overall x axis label.

   The newhistogram command can also be used to force histogram
coloring to begin with a specific color (linetype). By default colors
will continue to increment successively even across histogram
boundaries. Here is an example using the same coloring for multiple
histograms
           plot newhistogram "Set A" lt 4, 'a' using 1, '' using 2, '' using 3, \
                newhistogram "Set B" lt 4, 'b' using 1, '' using 2, '' using 3

   Similarly you can force the next histogram to begin with a specified
fillstyle.  If the fillstyle is set to `pattern`, then the pattern used
for filling will be incremented automatically.

   The `at <x-coord>` option sets the x coordinate position of the
following histogram to <x-coord>. For example

            set style histogram cluster
            set style data histogram
            set style fill solid 1.0 border -1
            set xtic 1 offset character 0,0.3
            plot newhistogram "Set A", \
                 'file.dat' u 1 t 1, '' u 2 t 2, \
                 newhistogram "Set B" at 8, \
                 'file.dat' u 2 t 2, '' u 2 t 2

   will position the second histogram to start at x=8.


File: gnuplot.info,  Node: automated_iteration_over_multiple_columns,  Prev: newhistogram,  Up: histograms

2.14.2 automated iteration over multiple columns
------------------------------------------------

If you want to create a histogram from many columns of data in a single
file, it is very convenient to use the plot iteration feature.  See
*note iteration::.  For example, to create stacked histograms of the
data in columns 3 through 8

           set style histogram columnstacked
           plot for [i=3:8] "datafile" using i title columnhead


File: gnuplot.info,  Node: image,  Next: impulses,  Prev: histograms,  Up: plotting_styles

2.15 image
==========

The `image`, *note rgbimage::, and *note rgbalpha:: plotting styles all
project a uniformly sampled grid of data values onto a plane  in either
2D or 3D.  The input data may be an actual bitmapped image, perhaps
converted from a standard format such as PNG, or a simple array of
numerical values.

   This figure illustrates generation of a heat map from an array of
scalar values.  The current palette is used to map each value onto the
color assigned to the corresponding pixel.
           plot '-' matrix with image
           5 4 3 1 0
           2 2 0 0 1
           0 0 0 1 0
           0 1 2 4 3
           e
           e

   Each pixel (data point) of the input 2D image will become a
rectangle or parallelipiped in the plot. The coordinates of each data
point will determine the center of the parallelipiped.  That is, an M x
N set of data will form an image with M x N pixels.  This is different
from the pm3d plotting style, where an M x N set of data will form a
surface of (M-1) x (N-1) elements.  The scan directions for a binary
image data grid can be further controlled by additional keywords. See
`binary keywords flipx`, `keywords center`, and `keywords rotate`.

   Image data can be scaled to fill a particular rectangle within a 2D
plot coordinate system by specifying the x and y extent of each pixel.
See `binary keywords dx` and `dy`. To generate the figure at the right,
the same input image was placed multiple times, each with a specified
dx, dy, and origin. The input PNG image of a building is 50x128 pixels.
The tall building was drawn by mapping this using `dx=0.5 dy=1.5`.  The
short building used a mapping `dx=0.5 dy=0.35`.

   The `image` style handles input pixels containing a grayscale or
color palette value. Thus 2D plots (`plot` command) require 3 columns
of data (x,y,value), while 3D plots (`splot` command) require 4 columns
of data (x,y,z,value).

   The *note rgbimage:: style handles input pixels that are described
by three separate values for the red, green, and blue components.  Thus
5D data (x,y,r,g,b) is needed for `plot` and 6D data (x,y,z,r,g,b) for
`splot`.  The individual red, green, and blue components are assumed to
lie in the range [0:255].

   The *note rgbalpha:: style handles input pixels that contain alpha
channel (transparency) information in addition to the red, green, and
blue components.  Thus 6D data (x,y,r,g,b,a) is needed for `plot` and
7D data (x,y,z,r,g,b,a) for `splot`.  The r, g, b, and alpha components
are assumed to lie in the range [0:255].

* Menu:

* transparency::
* image_failsafe::


File: gnuplot.info,  Node: transparency,  Next: image_failsafe,  Prev: image,  Up: image

2.15.1 transparency
-------------------

The *note rgbalpha:: plotting style assumes that each pixel of input
data contains an alpha value in the range [0:255].  A pixel with alpha
= 0 is purely transparent and does not alter the underlying contents of
the plot. A pixel with alpha = 255 is purely opaque.  All terminal
types can handle these two extreme cases.  A pixel with 0 < alpha < 255
is partially transparent.  Only a few terminal types can handle this
correctly; other terminals will approximate this by treating alpha as
being either 0 or 255.


File: gnuplot.info,  Node: image_failsafe,  Prev: transparency,  Up: image

2.15.2 image failsafe
---------------------

Some terminal drivers provide code to optimize rendering of image data
within a rectangular 2D area.  However this code is known to be
imperfect.  This optimized code may be disabled by using the keyword
`failsafe`. E.g.

           plot 'data' with image failsafe


File: gnuplot.info,  Node: impulses,  Next: labels,  Prev: image,  Up: plotting_styles

2.16 impulses
=============

The *note impulses:: style displays a vertical line from y=0 to the y
value of each point (2D) or from z=0 to the z value of each point (3D).
Note that the y or z values may be negative.  Data from additional
columns can be used to control the color of each impulse.  To use this
style effectively in 3D plots, it is useful to choose thick lines
(linewidth > 1). This approximates a 3D bar chart.

          1 column:   y
          2 columns:  x  y     # line from [x,0] to [x,y]  (2D)
          3 columns:  x  y  z  # line from [x,y,0] to [x,y,z] (3D)


File: gnuplot.info,  Node: labels,  Next: lines,  Prev: impulses,  Up: plotting_styles

2.17 labels
===========

The *note labels:: style reads coordinates and text from a data file
and places the text string at the corresponding 2D or 3D position.  3
or 4 input columns of basic data are required.  Additional input
columns may be used to provide information such as variable font size
or text color (see `rgbcolor variable`).

          3 columns:  x  y  string    # 2D version
          4 columns:  x  y  z  string # 3D version

   The font, color, rotation angle and other properties of the printed
text may be specified as additional command options (see `set label`).
The example below generates a 2D plot with text labels constructed from
the city whose name is taken from column 1 of the input file, and whose
geographic coordinates are in columns 4 and 5. The font size is
calculated from the value in column 3, in this case the population.

       CityName(String,Size) = sprintf("{/=%d %s}", Scale(Size), String)
       plot 'cities.dat' using 5:4:(CityName(stringcolumn(1),$3)) with labels

   If we did not want to adjust the font to a different size for each
city, the command would be much simpler:

       plot 'cities.dat' using 5:4:1 with labels font "Times,8"

   The *note labels:: style can also be used in 3D plots. In this case
four input column specifiers are required, corresponding to X Y Z and
text.

       splot 'datafile' using 1:2:3:4 with labels

   See also `datastrings`, `set style data`.


File: gnuplot.info,  Node: lines,  Next: linespoints,  Prev: labels,  Up: plotting_styles

2.18 lines
==========

The `lines` style connects adjacent points with straight line segments.
It may be used in either 2D or 3D plots. The basic form requires 1, 2,
or 3 columns of input data.  Additional input columns may be used to
provide information such as variable line color (see `rgbcolor
variable`).

   2D form
          1 column:   y       # implicit x from row number
          2 columns:  x  y

   3D form
          1 column:   z       # implicit x from row, y from index
          3 columns:  x  y  z

   See also `linetype`, `linewidth`, and `linestyle`.


File: gnuplot.info,  Node: linespoints,  Next: points,  Prev: lines,  Up: plotting_styles

2.19 linespoints
================

The *note linespoints:: style connects adjacent points with straight
line segments and then goes back to draw a small symbol at each point.
The command *note pointsize:: may be used to change the default size of
the points.  1 or 2 columns of basic input data are required in 2D
plots; 1 or 3 columns are required if 3D plots.  See `style lines`.
Additional input columns may be used to provide information such as
variable point size or line color.

   The `pointinterval` (short form `pi`) property of the linetype can
be used to control whether or not every point in the plot is given a
symbol.  For example, 'with lp pi 3' will draw line segments through
every data point, but will only place a symbol on every 3rd point.  A
negative value for `pointinterval` will erase the portion of line
segment that passes underneath the symbol. The size of the erased
portion is controlled by *note pointintervalbox::.

   *note linespoints:: may be abbreviated `lp`.


File: gnuplot.info,  Node: points,  Next: polar,  Prev: linespoints,  Up: plotting_styles

2.20 points
===========

The `points` style displays a small symbol at each point.  The command
*note pointsize:: may be used to change the default size of the points.
1 or 2 columns of basic input data are required in 2D plots; 1 or 3
columns are required in 3D plots.  See `style lines`.  Additional input
columns may be used to provide information such as variable point size
or variable point color.


File: gnuplot.info,  Node: polar,  Next: steps,  Prev: points,  Up: plotting_styles

2.21 polar
==========

Polar plots are not really a separate plot style but are listed here for
completeness.  The option `set polar` tells gnuplot to interpret input
2D coordinates as <angle>,<radius> rather than <x>,<y>.  Many, but not
all, 2D plotting styles work in polar mode.  The figure shows a
combination of plot styles `lines` and *note filledcurves::.  See `set
polar`, *note rrange::, `set size square`.


File: gnuplot.info,  Node: steps,  Next: rgbalpha,  Prev: polar,  Up: plotting_styles

2.22 steps
==========

The *note steps:: style is only relevant to 2D plotting.  It connects
consecutive points with two line segments: the first from (x1,y1) to
(x2,y1) and the second from (x2,y1) to (x2,y2).  The input column
requires are the same as for plot styles `lines` and `points`.  The
difference between *note fsteps:: and *note steps:: is that *note
fsteps:: traces first the change in y and then the change in x.  *note
steps:: traces first the change in x and then the change in y.  To fill
the area between the curve and the baseline at y=0, use *note
fillsteps::.  See also steps demo.
(http://www.gnuplot.info/demo/steps.html)


File: gnuplot.info,  Node: rgbalpha,  Next: rgbimage,  Prev: steps,  Up: plotting_styles

2.23 rgbalpha
=============

See `image`.


File: gnuplot.info,  Node: rgbimage,  Next: vectors,  Prev: rgbalpha,  Up: plotting_styles

2.24 rgbimage
=============

See `image`.


File: gnuplot.info,  Node: vectors,  Next: xerrorbars,  Prev: rgbimage,  Up: plotting_styles

2.25 vectors
============

The 2D *note vectors:: style draws a vector from (x,y) to
(x+xdelta,y+ydelta).  The 3D *note vectors:: style is similar, but
requires six columns of basic data.  A small arrowhead is drawn at the
end of each vector.

          4 columns:  x  y  xdelta  ydelta
          6 columns:  x  y  z  xdelta  ydelta  zdelta

   In both cases, an additional input column (5th in 2D, 7th in 3D) may
be used to provide variable (per-datapoint) color information.  (see
`linecolor` and `rgbcolor variable`).

   splot with vectors is supported only for `set mapping cartesian`.

   The keywords "with vectors" may be followed by an in-line arrow style
specifications, a reference to a predefined arrow style, or a request
to read the index of the desired arrow style for each vector from a
separate column.  Note: If you choose "arrowstyle variable" it will
fill in all arrow properties at the time the corresponding vector is
drawn; you cannot mix this keyword with other line or arrow style
qualifiers in the plot command.

          plot ... with vectors filled heads
          plot ... with vectors arrowstyle 3
          plot ... using 1:2:3:4:5 with vectors arrowstyle variable

   See `arrowstyle` for more details.

   Example:
           plot 'file.dat' using 1:2:3:4 with vectors head filled lt 2
           splot 'file.dat' using 1:2:3:(1):(1):(1) with vectors filled head lw 2

   `set clip one` and `set clip two` affect vectors drawn in 2D.
Please see `set clip` and `arrowstyle`.


File: gnuplot.info,  Node: xerrorbars,  Next: xyerrorbars,  Prev: vectors,  Up: plotting_styles

2.26 xerrorbars
===============

The *note xerrorbars:: style is only relevant to 2D data plots.  *note
xerrorbars:: is like `points`, except that a horizontal error bar is
also drawn.  At each point (x,y), a line is drawn from (xlow,y) to
(xhigh,y) or from (x-xdelta,y) to (x+xdelta,y), depending on how many
data columns are provided.  A tic mark is placed at the ends of the
error bar (unless *note bars:: is used--see *note bars:: for details).
The basic style requires either 3 or 4 columns:

          3 columns:  x  y  xdelta
          4 columns:  x  y  xlow  xhigh

   An additional input column (4th or 5th) may be used to provide
information such as variable point color.


File: gnuplot.info,  Node: xyerrorbars,  Next: yerrorbars,  Prev: xerrorbars,  Up: plotting_styles

2.27 xyerrorbars
================

The *note xyerrorbars:: style is only relevant to 2D data plots.  *note
xyerrorbars:: is like `points`, except that horizontal and vertical
error bars are also drawn.  At each point (x,y), lines are drawn from
(x,y-ydelta) to (x,y+ydelta) and from (x-xdelta,y) to (x+xdelta,y) or
from (x,ylow) to (x,yhigh) and from (xlow,y) to (xhigh,y), depending
upon the number of data columns provided.  A tic mark is placed at the
ends of the error bar (unless *note bars:: is used--see *note bars::
for details).  Either 4 or 6 input columns are required.

          4 columns:  x  y  xdelta  ydelta
          6 columns:  x  y  xlow  xhigh  ylow  yhigh

   If data are provided in an unsupported mixed form, the *note using::
filter on the `plot` command should be used to set up the appropriate
form.  For example, if the data are of the form
(x,y,xdelta,ylow,yhigh), then you can use

           plot 'data' using 1:2:($1-$3):($1+$3):4:5 with xyerrorbars

   An additional input column (5th or 7th) may be used to provide
variable (per-datapoint) color information.


File: gnuplot.info,  Node: yerrorbars,  Next: xerrorlines,  Prev: xyerrorbars,  Up: plotting_styles

2.28 yerrorbars
===============

The *note yerrorbars:: (or *note errorbars::) style is only relevant to
2D data plots.  *note yerrorbars:: is like `points`, except that a
vertical error bar is also drawn.  At each point (x,y), a line is drawn
from (x,y-ydelta) to (x,y+ydelta) or from (x,ylow) to (x,yhigh),
depending on how many data columns are provided.  A tic mark is placed
at the ends of the error bar (unless *note bars:: is used--see *note
bars:: for details).  Either 3 or 4 input columns are required.

          3 columns:  x  y  ydelta
          4 columns:  x  y  ylow  yhigh

   An additional input column (4th or 5th) may be used to provide
information such as variable point color.

   See also errorbar demo. (http://www.gnuplot.info/demo/mgr.html)


File: gnuplot.info,  Node: xerrorlines,  Next: xyerrorlines,  Prev: yerrorbars,  Up: plotting_styles

2.29 xerrorlines
================

The *note xerrorlines:: style is only relevant to 2D data plots.  *note
xerrorlines:: is like *note linespoints::, except that a horizontal
error line is also drawn. At each point (x,y), a line is drawn from
(xlow,y) to (xhigh,y) or from (x-xdelta,y) to (x+xdelta,y), depending
on how many data columns are provided. A tic mark is placed at the ends
of the error bar (unless *note bars:: is used--see *note bars:: for
details).  The basic style requires either 3 or 4 columns:

          3 columns:  x  y  xdelta
          4 columns:  x  y  xlow  xhigh

   An additional input column (4th or 5th) may be used to provide
information such as variable point color.


File: gnuplot.info,  Node: xyerrorlines,  Next: yerrorlines,  Prev: xerrorlines,  Up: plotting_styles

2.30 xyerrorlines
=================

The *note xyerrorlines:: style is only relevant to 2D data plots.
*note xyerrorlines:: is like *note linespoints::, except that
horizontal and vertical error bars are also drawn. At each point (x,y),
lines are drawn from (x,y-ydelta) to (x,y+ydelta) and from (x-xdelta,y)
to (x+xdelta,y) or from (x,ylow) to (x,yhigh) and from (xlow,y) to
(xhigh,y), depending upon the number of data columns provided. A tic
mark is placed at the ends of the error bar (unless *note bars:: is
used--see *note bars:: for details).  Either 4 or 6 input columns are
required.

          4 columns:  x  y  xdelta  ydelta
          6 columns:  x  y  xlow  xhigh  ylow  yhigh

   If data are provided in an unsupported mixed form, the *note using::
filter on the `plot` command should be used to set up the appropriate
form.  For example, if the data are of the form
(x,y,xdelta,ylow,yhigh), then you can use

           plot 'data' using 1:2:($1-$3):($1+$3):4:5 with xyerrorlines

   An additional input column (5th or 7th) may be used to provide
variable (per-datapoint) color information.


File: gnuplot.info,  Node: yerrorlines,  Next: 3D_(surface)_plots,  Prev: xyerrorlines,  Up: plotting_styles

2.31 yerrorlines
================

The *note yerrorlines:: (or *note errorlines::) style is only relevant
to 2D data plots. *note yerrorlines:: is like *note linespoints::,
except that a vertical error line is also drawn. At each point (x,y), a
line is drawn from (x,y-ydelta) to (x,y+ydelta) or from (x,ylow) to
(x,yhigh), depending on how many data columns are provided. A tic mark
is placed at the ends of the error bar (see *note bars:: for details).
Either 3 or 4 input columns are required.

          3 columns:  x  y  ydelta
          4 columns:  x  y  ylow  yhigh

   An additional input column (4th or 5th) may be used to provide
information such as variable point color.

   See also errorbar demo. (http://www.gnuplot.info/demo/mgr.html)


File: gnuplot.info,  Node: 3D_(surface)_plots,  Prev: yerrorlines,  Up: plotting_styles

2.32 3D (surface) plots
=======================

Surface plots are generated using the `splot` command rather than the
`plot` command. The style `with lines` draws a surface made from a grid
of lines.  Solid surfaces can be drawn using the style *note pm3d::.
Usually the surface is displayed at some arbitrary viewing angle, such
that it clearly represents a 3D surface.  In this case the X, Y, and Z
axes are all visible in the plot. The illusion of 3D is enhanced by
choosing hidden line removal or depth-sorted surface elements.  See
*note hidden3d:: and `pm3d depthorder`.  The `splot` command can also
calculate and draw contour lines corresponding to constant Z values.
These contour lines may be drawn onto the surface itself, or projected
onto the XY plane. See *note contour::.

* Menu:

* 2D_projection_(set_view_map)::


File: gnuplot.info,  Node: 2D_projection_(set_view_map),  Prev: 3D_(surface)_plots,  Up: 3D_(surface)_plots

2.32.1 2D projection (set view map)
-----------------------------------

An important special case of the `splot` command is to map the Z
coordinate onto a 2D surface by projecting the plot along the Z axis.
See `set view map`.  This plot mode can be used to generate contour
plots and heat maps.


File: gnuplot.info,  Node: Commands,  Next: Terminal_types,  Prev: plotting_styles,  Up: Top

3 Commands
**********

This section lists the commands acceptable to `gnuplot` in alphabetical
order.  Printed versions of this document contain all commands; the text
available interactively may not be complete.  Indeed, on some systems
there may be no commands at all listed under this heading.

   Note that in most cases unambiguous abbreviations for command names
and their options are permissible, i.e., "`p f(x) w li`" instead of
"`plot f(x) with lines`".

   In the syntax descriptions, braces ({}) denote optional arguments
and a vertical bar (|) separates mutually exclusive choices.

* Menu:

* cd::
* call::
* clear::
* Do::
* evaluate::
* exit::
* fit::
* help::
* history::
* if::
* iteration::
* load::
* lower::
* pause::
* plot::
* print::
* pwd::
* quit::
* raise::
* refresh::
* replot::
* reread::
* reset::
* save::
* set-show::
* shell::
* splot::
* stats_(Statistical_Summary)::
* system_::
* test::
* undefine::
* unset::
* update::
* While::


File: gnuplot.info,  Node: cd,  Next: call,  Prev: Commands,  Up: Commands

3.1 cd
======

The *note cd:: command changes the working directory.

   Syntax:
           cd '<directory-name>'

   The directory name must be enclosed in quotes.

   Examples:
           cd 'subdir'
           cd ".."

   It is recommended that Windows users use single-quotes, because
backslash [\] has special significance inside double-quotes and has to
be escaped.  For example,
           cd "c:\newdata"

   fails, but
           cd 'c:\newdata'
           cd "c:\\newdata"

   work as expected.


File: gnuplot.info,  Node: call,  Next: clear,  Prev: cd,  Up: Commands

3.2 call
========

The *note call:: command is identical to the load command with one
exception: you can have up to ten additional parameters to the command
(delimited according to the standard parser rules) which can be
substituted into the lines read from the file.  As each line is read
from the *note call::ed input file, it is scanned for the sequence `$`
(dollar-sign) followed by a digit (0-9).  If found, the sequence is
replaced by the corresponding parameter from the *note call:: command
line.  If the parameter was specified as a string in the *note call::
line, it is substituted without its enclosing quotes.  Sequence `$#` is
replaced by the number of passed parameters.  `$` followed by any
character will be that character; e.g. use `$$` to get a single `$`.
Providing more than ten parameters on the *note call:: command line
will cause an error.  A parameter that was not provided substitutes as
nothing.  Files being *note call::ed may themselves contain *note
call:: or `load` commands.

   Syntax:
           call "<input-file>" <parameter-0> <parm-1> ... <parm-9>

   The name of the input file must be enclosed in quotes, and it is
recommended that parameters are similarly enclosed in quotes (future
versions of gnuplot may treat quoted and unquoted arguments
differently).

   Example:

   If the file 'calltest.gp' contains the line:
           print "argc=$# p0=$0 p1=$1 p2=$2 p3=$3 p4=$4 p5=$5 p6=$6 p7=x$7x"

   entering the command:
           call 'calltest.gp' "abcd" 1.2 + "'quoted'" -- "$2"

   will display:
           argc=7 p0=abcd p1=1.2 p2=+ p3='quoted' p4=- p5=- p6=$2 p7=xx

   NOTE: there is a clash in syntax with the datafile *note using::
callback operator.  Use `$$n` or `column(n)` to access column n from a
datafile inside a *note call::ed datafile plot.


File: gnuplot.info,  Node: clear,  Next: Do,  Prev: call,  Up: Commands

3.3 clear
=========

The *note clear:: command erases the current screen or output device as
specified by *note output::.  This usually generates a formfeed on
hardcopy devices.  Use *note terminal:: to set the device type.

   For some terminals *note clear:: erases only the portion of the
plotting surface defined by *note size::, so for these it can be used
in conjunction with *note multiplot:: to create an inset.

   Example:
           set multiplot
           plot sin(x)
           set origin 0.5,0.5
           set size 0.4,0.4
           clear
           plot cos(x)
           unset multiplot

   Please see *note multiplot::, *note size::, and *note origin:: for
details of these commands.


File: gnuplot.info,  Node: Do,  Next: evaluate,  Prev: clear,  Up: Commands

3.4 Do
======

Syntax:
           do for <iteration-spec> {
                <commands>
                <commands>
           }

   Execute a sequence of commands multiple times.  The commands must be
enclosed in curly brackets, and the opening "{" must be on the same
line as the `do` keyword.  This command cannot be used with old-style
(un-bracketed) if/else statements.  See `if`.  For examples of
iteration specifiers, see *note iteration::.  Example:
           set multiplot layout 2,2
           do for [name in "A B C D"] {
               filename = name . ".dat"
               set title sprintf("Condition %s",name)
               plot filename title name
           }
           unset multiplot


File: gnuplot.info,  Node: evaluate,  Next: exit,  Prev: Do,  Up: Commands

3.5 evaluate
============

The *note evaluate:: command executes the commands given as an argument
string.  Newline characters are not allowed within the string.

   Syntax:
           eval <string expression>

   This is especially useful for a repetition of similar commands.

   Example:
           set_label(x, y, text) \
             = sprintf("set label '%s' at %f, %f point pt 5", text, x, y)
           eval set_label(1., 1., 'one/one')
           eval set_label(2., 1., 'two/one')
           eval set_label(1., 2., 'one/two')

   Please see *note macros:: for another way to execute commands from a
string.


File: gnuplot.info,  Node: exit,  Next: fit,  Prev: evaluate,  Up: Commands

3.6 exit
========

The commands *note exit:: and *note quit::, as well as the END-OF-FILE
character (usually Ctrl-D) terminate input from the current input
stream: terminal session, pipe, and file input (pipe).

   If input streams are nested (inherited `load` scripts), then reading
will continue in the parent stream. When the top level stream is
closed, the program itself will exit.

   The command `exit gnuplot` will immediately and unconditionally
cause gnuplot to exit even if the input stream is multiply nested.  In
this case any open output files may not be completed cleanly. Example
of use:

           bind "ctrl-x" "unset output; exit gnuplot"

   See help for `batch/interactive` for more details.


File: gnuplot.info,  Node: fit,  Next: help,  Prev: exit,  Up: Commands

3.7 fit
=======

The *note fit:: command can fit a user-supplied expression to a set of
data points (x,z) or (x,y,z), using an implementation of the nonlinear
least-squares (NLLS) Marquardt-Levenberg algorithm.  Any user-defined
variable occurring in the expression may serve as a fit parameter, but
the return type of the expression must be real.

   Syntax:
           fit {<ranges>} <expression>
               '<datafile>' {datafile-modifiers}
               via '<parameter file>' | <var1>{,<var2>,...}

   Ranges may be specified to temporarily limit the data which is to be
fitted; any out-of-range data points are ignored. The syntax is
           [{dummy_variable=}{<min>}{:<max>}],

   analogous to `plot`; see *note ranges::.

   <expression> is any valid `gnuplot` expression, although it is usual
to use a previously user-defined function of the form f(x) or f(x,y).

   <datafile> is treated as in the `plot` command.  All the *note
datafile:: modifiers (*note using::, *note every::,...) except *note
smooth:: and the deprecated *note thru:: are applicable to *note fit::.
See *note datafile::.

   The default data formats for fitting functions with a single
independent variable, z=f(x), are z or x:z.  That is, if there is only
a single column then it is the dependent variable and the line numbers
is the independent variable.  If there are two columns, the first is
the independent variable and the second is the dependent variable.

   Those formats can be changed with the datafile *note using::
qualifier, for example to take the z value from a different column or
to calculate it from several columns.  A third *note using:: qualifier
(a column number or an expression), if present, is interpreted as the
standard deviation of the corresponding z value and is used to compute a
weight for the datum, 1/s**2.  Otherwise, all data points are weighted
equally, with a weight of one. Note that if you don't specify a *note
using:: option at all, no z standard deviations are read from the
datafile even if it does have a third column, so you'll always get unit
weights.

   To fit a function with two independent variables, z=f(x,y), the
required format is *note using:: with four items, x:y:z:s.  The
complete format must be given--no default columns are assumed for a
missing token.  Weights for each data point are evaluated from 's' as
above.  If error estimates are not available, a constant value can be
specified as a constant expression (see *note using::), e.g., `using
1:2:3:(1)`.

   The fit function may have up to five independent variables.  There
must be two more *note using:: qualifiers than there are independent
variables, unless there is only one variable.  The allowed formats, and
the default dummy variable names, are as follows:

           z
           x:z
           x:z:s
           x:y:z:s
           x:y:t:z:s
           x:y:t:u:z:s
           x:y:t:u:v:z:s

   The dummy variable names may be changed with ranges as noted above.
The first range corresponds to the first *note using:: spec, etc.  A
range may also be given for z (the dependent variable), but that name
cannot be changed.

   Multiple datasets may be simultaneously fit with functions of one
independent variable by making y a 'pseudo-variable', e.g., the dataline
number, and fitting as two independent variables.  See *note
multi-branch::.

   The `via` qualifier specifies which parameters are to be adjusted,
either directly, or by referencing a parameter file.

   Examples:
           f(x) = a*x**2 + b*x + c
           g(x,y) = a*x**2 + b*y**2 + c*x*y
           FIT_LIMIT = 1e-6
           fit f(x) 'measured.dat' via 'start.par'
           fit f(x) 'measured.dat' using 3:($7-5) via 'start.par'
           fit f(x) './data/trash.dat' using 1:2:3 via a, b, c
           fit g(x,y) 'surface.dat' using 1:2:3:(1) via a, b, c
           fit a0 + a1*x/(1 + a2*x/(1 + a3*x)) 'measured.dat' via a0,a1,a2,a3
           fit a*x + b*y 'surface.dat' using 1:2:3:(1) via a,b
           fit [*:*][yaks=*:*] a*x+b*yaks 'surface.dat' u 1:2:3:(1) via a,b
           fit a*x + b*y + c*t 'foo.dat' using 1:2:3:4:(1) via a,b,c
           h(x,y,t,u,v) = a*x + b*y + c*t + d*u + e*v
           fit h(x,y,t,u,v) 'foo.dat' using 1:2:3:4:5:6:(1) via a,b,c,d,e

   After each iteration step, detailed information about the current
state of the fit is written to the display.  The same information about
the initial and final states is written to a log file, "fit.log".  This
file is always appended to, so as to not lose any previous fit history;
it should be deleted or renamed as desired. By using the command `set
fit logfile`, the name of the log file can be changed.

   If gnuplot was built with this option, and you activated it using
`set fit errorvariables`, the error for each fitted parameter will be
stored in a variable named like the parameter, but with "_err"
appended.  Thus the errors can be used as input for further
computations.

   The fit may be interrupted by pressing Ctrl-C.  After the current
iteration completes, you have the option to (1) stop the fit and accept
the current parameter values, (2) continue the fit, (3) execute a
`gnuplot` command as specified by the environment variable FIT_SCRIPT.
The default for FIT_SCRIPT is *note replot::, so if you had previously
plotted both the data and the fitting function in one graph, you can
display the current state of the fit.

   Once *note fit:: has finished, the *note update:: command may be
used to store final values in a file for subsequent use as a parameter
file.   See *note update:: for details.

* Menu:

* adjustable_parameters::
* short_introduction::
* error_estimates::
* control::
* multi-branch::
* starting_values::
* tips::


File: gnuplot.info,  Node: adjustable_parameters,  Next: short_introduction,  Prev: fit,  Up: fit

3.7.1 adjustable parameters
---------------------------

There are two ways that `via` can specify the parameters to be adjusted,
either directly on the command line or indirectly, by referencing a
parameter file.  The two use different means to set initial values.

   Adjustable parameters can be specified by a comma-separated list of
variable names after the `via` keyword.  Any variable that is not
already defined is created with an initial value of 1.0.  However, the
fit is more likely to converge rapidly if the variables have been
previously declared with more appropriate starting values.

   In a parameter file, each parameter to be varied and a corresponding
initial value are specified, one per line, in the form
           varname = value

   Comments, marked by '#', and blank lines are permissible.  The
special form
           varname = value       # FIXED

   means that the variable is treated as a 'fixed parameter',
initialized by the parameter file, but not adjusted by *note fit::.
For clarity, it may be useful to designate variables as fixed
parameters so that their values are reported by *note fit::.  The
keyword `# FIXED` has to appear in exactly this form.


File: gnuplot.info,  Node: short_introduction,  Next: error_estimates,  Prev: adjustable_parameters,  Up: fit

3.7.2 short introduction
------------------------

*note fit:: is used to find a set of parameters that 'best' fits your
data to your user-defined function.  The fit is judged on the basis of
the sum of the squared differences or 'residuals' (SSR) between the
input data points and the function values, evaluated at the same
places.  This quantity is often called 'chisquare' (i.e., the Greek
letter chi, to the power of 2).  The algorithm attempts to minimize
SSR, or more precisely, WSSR, as the residuals are 'weighted' by the
input data errors (or 1.0) before being squared; see `fit
error_estimates` for details.

   That's why it is called 'least-squares fitting'.  Let's look at an
example to see what is meant by 'non-linear', but first we had better
go over some terms.  Here it is convenient to use z as the dependent
variable for user-defined functions of either one independent variable,
z=f(x), or two independent variables, z=f(x,y).  A parameter is a
user-defined variable that *note fit:: will adjust, i.e., an unknown
quantity in the function declaration.  Linearity/non-linearity refers
to the relationship of the dependent variable, z, to the parameters
which *note fit:: is adjusting, not of z to the independent variables,
x and/or y.  (To be technical, the second {and higher} derivatives of
the fitting function with respect to the parameters are zero for a
linear least-squares problem).

   For linear least-squares (LLS), the user-defined function will be a
sum of simple functions, not involving any parameters, each multiplied
by one parameter.  NLLS handles more complicated functions in which
parameters can be used in a large number of ways.  An example that
illustrates the difference between linear and nonlinear least-squares
is the Fourier series.  One member may be written as
          z=a*sin(c*x) + b*cos(c*x).

   If a and b are the unknown parameters and c is constant, then
estimating values of the parameters is a linear least-squares problem.
However, if c is an unknown parameter, the problem is nonlinear.

   In the linear case, parameter values can be determined by
comparatively simple linear algebra, in one direct step.  However LLS
is a special case which is also solved along with more general NLLS
problems by the iterative procedure that `gnuplot` uses.  *note fit::
attempts to find the minimum by doing a search.  Each step (iteration)
calculates WSSR with a new set of parameter values.  The
Marquardt-Levenberg algorithm selects the parameter values for the next
iteration.  The process continues until a preset criterion is met,
either (1) the fit has "converged" (the relative change in WSSR is less
than FIT_LIMIT), or (2) it reaches a preset iteration count limit,
FIT_MAXITER (see *note variables::).  The fit may also be interrupted
and subsequently halted from the keyboard (see *note fit::).  The user
variable FIT_CONVERGED contains 1 if the previous fit command
terminated due to convergence; it contains 0 if the previous fit
terminated for any other reason.

   Often the function to be fitted will be based on a model (or theory)
that attempts to describe or predict the behaviour of the data.  Then
*note fit:: can be used to find values for the free parameters of the
model, to determine how well the data fits the model, and to estimate
an error range for each parameter.  See `fit error_estimates`.

   Alternatively, in curve-fitting, functions are selected independent
of a model (on the basis of experience as to which are likely to
describe the trend of the data with the desired resolution and a
minimum number of parameters*functions.)  The *note fit:: solution then
provides an analytic representation of the curve.

   However, if all you really want is a smooth curve through your data
points, the *note smooth:: option to `plot` may be what you've been
looking for rather than *note fit::.


File: gnuplot.info,  Node: error_estimates,  Next: control,  Prev: short_introduction,  Up: fit

3.7.3 error estimates
---------------------

In *note fit::, the term "error" is used in two different contexts,
data error estimates and parameter error estimates.

   Data error estimates are used to calculate the relative weight of
each data point when determining the weighted sum of squared residuals,
WSSR or chisquare.  They can affect the parameter estimates, since they
determine how much influence the deviation of each data point from the
fitted function has on the final values.  Some of the *note fit::
output information, including the parameter error estimates, is more
meaningful if accurate data error estimates have been provided.

   The 'statistical overview' describes some of the *note fit:: output
and gives some background for the 'practical guidelines'.

* Menu:

* statistical_overview::
* practical_guidelines::


File: gnuplot.info,  Node: statistical_overview,  Next: practical_guidelines,  Prev: error_estimates,  Up: error_estimates

3.7.3.1 statistical overview
............................

The theory of non-linear least-squares (NLLS) is generally described in
terms of a normal distribution of errors, that is, the input data is
assumed to be a sample from a population having a given mean and a
Gaussian (normal) distribution about the mean with a given standard
deviation.  For a sample of sufficiently large size, and knowing the
population standard deviation, one can use the statistics of the
chisquare distribution to describe a "goodness of fit" by looking at
the variable often called "chisquare".  Here, it is sufficient to say
that a reduced chisquare (chisquare/degrees of freedom, where degrees
of freedom is the number of datapoints less the number of parameters
being fitted) of 1.0 is an indication that the weighted sum of squared
deviations between the fitted function and the data points is the same
as that expected for a random sample from a population characterized by
the function with the current value of the parameters and the given
standard deviations.

   If the standard deviation for the population is not constant, as in
counting statistics where variance = counts, then each point should be
individually weighted when comparing the observed sum of deviations and
the expected sum of deviations.

   At the conclusion *note fit:: reports 'stdfit', the standard
deviation of the fit, which is the rms of the residuals, and the
variance of the residuals, also called 'reduced chisquare' when the
data points are weighted.  The number of degrees of freedom (the number
of data points minus the number of fitted parameters) is used in these
estimates because the parameters used in calculating the residuals of
the datapoints were obtained from the same data.  These values are
exported to the variables
           FIT_NDF = Number of degrees of freedom
           FIT_WSSR = Weighted sum-of-squares residual
           FIT_STDFIT = sqrt(WSSR/NDF)

   To estimate confidence levels for the parameters, one can use the
minimum chisquare obtained from the fit and chisquare statistics to
determine the value of chisquare corresponding to the desired
confidence level, but considerably more calculation is required to
determine the combinations of parameters which produce such values.

   Rather than determine confidence intervals, *note fit:: reports
parameter error estimates which are readily obtained from the
variance-covariance matrix after the final iteration.  By convention,
these estimates are called "standard errors" or "asymptotic standard
errors", since they are calculated in the same way as the standard
errors (standard deviation of each parameter) of a linear least-squares
problem, even though the statistical conditions for designating the
quantity calculated to be a standard deviation are not generally valid
for the NLLS problem.  The asymptotic standard errors are generally
over-optimistic and should not be used for determining confidence
levels, but are useful for qualitative purposes.

   The final solution also produces a correlation matrix indicating
correlation of parameters in the region of the solution; The main
diagonal elements, autocorrelation, are always 1; if all parameters
were independent, the off-diagonal elements would be nearly 0.  Two
variables which completely compensate each other would have an
off-diagonal element of unit magnitude, with a sign depending on
whether the relation is proportional or inversely proportional.  The
smaller the magnitudes of the off-diagonal elements, the closer the
estimates of the standard deviation of each parameter would be to the
asymptotic standard error.


File: gnuplot.info,  Node: practical_guidelines,  Prev: statistical_overview,  Up: error_estimates

3.7.3.2 practical guidelines
............................

If you have a basis for assigning weights to each data point, doing so
lets you make use of additional knowledge about your measurements,
e.g., take into account that some points may be more reliable than
others.  That may affect the final values of the parameters.

   Weighting the data provides a basis for interpreting the additional
*note fit:: output after the last iteration.  Even if you weight each
point equally, estimating an average standard deviation rather than
using a weight of 1 makes WSSR a dimensionless variable, as chisquare
is by definition.

   Each fit iteration will display information which can be used to
evaluate the progress of the fit.  (An '*' indicates that it did not
find a smaller WSSR and is trying again.)  The 'sum of squares of
residuals', also called 'chisquare', is the WSSR between the data and
your fitted function; *note fit:: has minimized that.  At this stage,
with weighted data, chisquare is expected to approach the number of
degrees of freedom (data points minus parameters).  The WSSR can be
used to calculate the reduced chisquare (WSSR/ndf) or stdfit, the
standard deviation of the fit, sqrt(WSSR/ndf).  Both of these are
reported for the final WSSR.

   If the data are unweighted, stdfit is the rms value of the deviation
of the data from the fitted function, in user units.

   If you supplied valid data errors, the number of data points is
large enough, and the model is correct, the reduced chisquare should be
about unity.  (For details, look up the 'chi-squared distribution' in
your favourite statistics reference.)  If so, there are additional
tests, beyond the scope of this overview, for determining how well the
model fits the data.

   A reduced chisquare much larger than 1.0 may be due to incorrect
data error estimates, data errors not normally distributed, systematic
measurement errors, 'outliers', or an incorrect model function.  A plot
of the residuals, e.g., `plot 'datafile' using 1:($2-f($1))`, may help
to show any systematic trends.  Plotting both the data points and the
function may help to suggest another model.

   Similarly, a reduced chisquare less than 1.0 indicates WSSR is less
than that expected for a random sample from the function with normally
distributed errors.  The data error estimates may be too large, the
statistical assumptions may not be justified, or the model function may
be too general, fitting fluctuations in a particular sample in addition
to the underlying trends.  In the latter case, a simpler function may
be more appropriate.

   You'll have to get used to both *note fit:: and the kind of problems
you apply it to before you can relate the standard errors to some more
practical estimates of parameter uncertainties or evaluate the
significance of the correlation matrix.

   Note that *note fit::, in common with most NLLS implementations,
minimizes the weighted sum of squared distances (y-f(x))**2.  It does
not provide any means to account for "errors" in the values of x, only
in y.  Also, any "outliers" (data points outside the normal
distribution of the model) will have an exaggerated effect on the
solution.


File: gnuplot.info,  Node: control,  Next: multi-branch,  Prev: error_estimates,  Up: fit

3.7.4 control
-------------

There are a number of `gnuplot` variables that can be defined to affect
*note fit::.  Those which can be defined once `gnuplot` is running are
listed under 'control_variables' while those defined before starting
`gnuplot` are listed under 'environment_variables'.

* Menu:

* control_variables::
* environment_variables::


File: gnuplot.info,  Node: control_variables,  Next: environment_variables,  Prev: control,  Up: control

3.7.4.1 control variables
.........................

The default epsilon limit (1e-5) may be changed by declaring a value for
           FIT_LIMIT

   When the sum of squared residuals changes between two iteration
steps by a factor less than this number (epsilon), the fit is
considered to have 'converged'.

   The maximum number of iterations may be limited by declaring a value
for
           FIT_MAXITER

   A value of 0 (or not defining it at all)  means that there is no
limit.

   If you need even more control about the algorithm, and know the
Marquardt-Levenberg algorithm well, there are some more variables to
influence it. The startup value of `lambda` is normally calculated
automatically from the ML-matrix, but if you want to, you may provide
your own one with
           FIT_START_LAMBDA

   Specifying FIT_START_LAMBDA as zero or less will re-enable the
automatic selection. The variable
           FIT_LAMBDA_FACTOR

   gives the factor by which `lambda` is increased or decreased whenever
the chi-squared target function increased or decreased significantly.
Setting FIT_LAMBDA_FACTOR to zero re-enables the default factor of 10.0.

   Other variables with the FIT_ prefix may be added to *note fit::, so
it is safer not to use that prefix for user-defined variables.

   The variables FIT_SKIP and FIT_INDEX were used by earlier releases of
`gnuplot` with a 'fit' patch called `gnufit` and are no longer
available.  The datafile *note every:: modifier provides the
functionality of FIT_SKIP.  FIT_INDEX was used for multi-branch
fitting, but multi-branch fitting of one independent variable is now
done as a pseudo-3D fit in which the second independent variable and
*note using:: are used to specify the branch.  See *note multi-branch::.


File: gnuplot.info,  Node: environment_variables,  Prev: control_variables,  Up: control

3.7.4.2 environment variables
.............................

The environment variables must be defined before `gnuplot` is executed;
how to do so depends on your operating system.

           FIT_LOG

   changes the name (and/or path) of the file to which the fit log will
be written from the default of "fit.log" in the working directory. The
default value can be overwritten using the command `set fit logfile`.

           FIT_SCRIPT

   specifies a command that may be executed after an user interrupt.
The default is *note replot::, but a `plot` or `load` command may be
useful to display a plot customized to highlight the progress of the
fit.


File: gnuplot.info,  Node: multi-branch,  Next: starting_values,  Prev: control,  Up: fit

3.7.5 multi-branch
------------------

In multi-branch fitting, multiple data sets can be simultaneously fit
with functions of one independent variable having common parameters by
minimizing the total WSSR.  The function and parameters (branch) for
each data set are selected by using a 'pseudo-variable', e.g., either
the dataline number (a 'column' index of -1) or the datafile index
(-2), as the second independent variable.

   Example:  Given two exponential decays of the form, z=f(x), each
describing a different data set but having a common decay time,
estimate the values of the parameters.  If the datafile has the format
x:z:s, then
          f(x,y) = (y==0) ? a*exp(-x/tau) : b*exp(-x/tau)
          fit f(x,y) 'datafile' using  1:-2:2:3  via a, b, tau

   For a more complicated example, see the file "hexa.fnc" used by the
"fit.dem" demo.

   Appropriate weighting may be required since unit weights may cause
one branch to predominate if there is a difference in the scale of the
dependent variable.  Fitting each branch separately, using the
multi-branch solution as initial values, may give an indication as to
the relative effect of each branch on the joint solution.


File: gnuplot.info,  Node: starting_values,  Next: tips,  Prev: multi-branch,  Up: fit

3.7.6 starting values
---------------------

Nonlinear fitting is not guaranteed to converge to the global optimum
(the solution with the smallest sum of squared residuals, SSR), and can
get stuck at a local minimum.  The routine has no way to determine
that;  it is up to you to judge whether this has happened.

   *note fit:: may, and often will get "lost" if started far from a
solution, where SSR is large and changing slowly as the parameters are
varied, or it may reach a numerically unstable region (e.g., too large
a number causing a floating point overflow) which results in an
"undefined value" message or `gnuplot` halting.

   To improve the chances of finding the global optimum, you should set
the starting values at least roughly in the vicinity of the solution,
e.g., within an order of magnitude, if possible.  The closer your
starting values are to the solution, the less chance of stopping at
another minimum.  One way to find starting values is to plot data and
the fitting function on the same graph and change parameter values and
*note replot:: until reasonable similarity is reached.  The same plot
is also useful to check whether the fit stopped at a minimum with a
poor fit.

   Of course, a reasonably good fit is not proof there is not a
"better" fit (in either a statistical sense, characterized by an
improved goodness-of-fit criterion, or a physical sense, with a
solution more consistent with the model.)  Depending on the problem, it
may be desirable to *note fit:: with various sets of starting values,
covering a reasonable range for each parameter.


File: gnuplot.info,  Node: tips,  Prev: starting_values,  Up: fit

3.7.7 tips
----------

Here are some tips to keep in mind to get the most out of *note fit::.
They're not very organized, so you'll have to read them several times
until their essence has sunk in.

   The two forms of the `via` argument to *note fit:: serve two largely
distinct purposes.  The `via "file"` form is best used for (possibly
unattended) batch operation, where you just supply the startup values
in a file and can later use *note update:: to copy the results back
into another (or the same) parameter file.

   The `via var1, var2, ...` form is best used interactively, where the
command history mechanism may be used to edit the list of parameters to
be fitted or to supply new startup values for the next try.  This is
particularly useful for hard problems, where a direct fit to all
parameters at once won't work without good starting values.  To find
such, you can iterate several times, fitting only some of the
parameters, until the values are close enough to the goal that the
final fit to all parameters at once will work.

   Make sure that there is no mutual dependency among parameters of the
function you are fitting.  For example, don't try to fit a*exp(x+b),
because a*exp(x+b)=a*exp(b)*exp(x).  Instead, fit either a*exp(x) or
exp(x+b).

   A technical issue:  the parameters must not be too different in
magnitude.  The larger the ratio of the largest and the smallest
absolute parameter values, the slower the fit will converge.  If the
ratio is close to or above the inverse of the machine floating point
precision, it may take next to forever to converge, or refuse to
converge at all.  You will have to adapt your function to avoid this,
e.g., replace 'parameter' by '1e9*parameter' in the function
definition, and divide the starting value by 1e9.

   If you can write your function as a linear combination of simple
functions weighted by the parameters to be fitted, by all means do so.
That helps a lot, because the problem is no longer nonlinear and should
converge with only a small number of iterations, perhaps just one.

   Some prescriptions for analysing data, given in practical
experimentation courses, may have you first fit some functions to your
data, perhaps in a multi-step process of accounting for several aspects
of the underlying theory one by one, and then extract the information
you really wanted from the fitting parameters of those functions.  With
*note fit::, this may often be done in one step by writing the model
function directly in terms of the desired parameters.  Transforming
data can also quite often be avoided, though sometimes at the cost of a
more difficult fit problem.  If you think this contradicts the previous
paragraph about simplifying the fit function, you are correct.

   A "singular matrix" message indicates that this implementation of the
Marquardt-Levenberg algorithm can't calculate parameter values for the
next iteration.  Try different starting values, writing the function in
another form, or a simpler function.

   Finally, a nice quote from the manual of another fitting package
(fudgit), that kind of summarizes all these issues:  "Nonlinear fitting
is an art!"


File: gnuplot.info,  Node: help,  Next: history,  Prev: fit,  Up: Commands

3.8 help
========

The *note help:: command displays built-in help. To specify information
on a particular topic use the syntax:

           help {<topic>}

   If <topic> is not specified, a short message is printed about
`gnuplot`.  After help for the requested topic is given, a menu of
subtopics is given; help for a subtopic may be requested by typing its
name, extending the help request.  After that subtopic has been
printed, the request may be extended again or you may go back one level
to the previous topic.  Eventually, the `gnuplot` command line will
return.

   If a question mark (?) is given as the topic, the list of topics
currently available is printed on the screen.


File: gnuplot.info,  Node: history,  Next: if,  Prev: help,  Up: Commands

3.9 history
===========

`history` command lists or saves previous entries in the history of the
command line editing, or executes an entry.

   Here you find 'usage by examples':

           history               # show the complete history
           history 5             # show last 5 entries in the history
           history quiet 5       # show last 5 entries without entry numbers
           history "hist.gp"     # write the complete history to file hist.gp
           history "hist.gp" append # append the complete history to file hist.gp
           history 10 "hist.gp"  # write last 10 commands to file hist.gp
           history 10 "|head -5 >>diary.gp" # write 5 history commands using pipe
           history ?load         # show all history entries starting with "load"
           history ?"set c"      # like above, several words enclosed in quotes
           hi !reread            # execute last entry starting with "reread"
           hist !"set xr"        # like above, several words enclosed in quotes
           hi !hi                # guess yourself :-))

   On systems which support a popen function (Unix), the output of
history can be piped through an external program by starting the file
name with a '|', as one of the above examples demonstrates.


File: gnuplot.info,  Node: if,  Next: iteration,  Prev: history,  Up: Commands

3.10 if
=======

New syntax:
           if (<condition>) { <command>; <command>
                  <commands>
                  <commands>
           } else {
                  <commands>
           }

   Old syntax:
           if (<condition>) <command-line> [; else if (<condition>) ...; else ...]

   This version of gnuplot supports block-structured if/else
statements. If the keyword `if` or `else` is immediately followed by an
opening "{", then conditional execution applies to all statements,
possibly on multiple input lines, until a matching "}" terminates the
block.  If commands may be nested.

   The old single-line if/else syntax is still supported, but can not be
mixed with the new block-structured syntax.  See *note if-old::.

* Menu:

* if-old::


File: gnuplot.info,  Node: if-old,  Prev: if,  Up: if

3.10.1 if-old
-------------

Through gnuplot version 4.4, the scope of the if/else commands was
limited to a single input line. This has been replaced by allowing a
multi-line clause to be enclosed in curly brackets. The old syntax is
still honored by itself but cannot be used inside a bracketed clause.

   If no opening "{" follows the `if` keyword, the command(s) in
<command-line> will be executed if <condition> is true (non-zero) or
skipped if <condition> is false (zero). Either case will consume
commands on the input line until the end of the line or an occurrence
of `else`.  Note that use of `;` to allow multiple commands on the same
line will _not_ end the conditionalized commands.

   Examples:
           pi=3
           if (pi!=acos(-1)) print "?Fixing pi!"; pi=acos(-1); print pi

   will display:
           ?Fixing pi!
           3.14159265358979

   but
           if (1==2) print "Never see this"; print "Or this either"

   will not display anything.

   else:
           v=0
           v=v+1; if (v%2) print "2" ; else if (v%3) print "3"; else print "fred"

   (repeat the last line repeatedly!)

   See *note reread:: for an example of using if and reread together to
perform a loop.


File: gnuplot.info,  Node: iteration,  Next: load,  Prev: if,  Up: Commands

3.11 iteration
==============

The `plot`, `splot`, `set` and *note unset:: commands may optionally
contain an iteration clause.  This has the effect of executing the
basic command multiple times, each time re-evaluating any expressions
that make use of the iteration control variable.  Iteration of
arbitrary command sequences can be requested using the `do` command.
Two forms of iteration clause are currently supported:

           for [intvar = start:end{:increment}]
           for [stringvar in "A B C D"]

   Examples:

           plot for [filename in "A.dat B.dat C.dat"] filename using 1:2 with lines
           plot for [basename in "A B C"] basename.".dat" using 1:2 with lines
           set for [i = 1:10] style line i lc rgb "blue"
           unset for [tag = 100:200] label tag

   Nested iteration is supported:

           set for [i=1:9] for [j=1:9] label i*10+j sprintf("%d",i*10+j) at i,j

   See additional documentation for *note iteration::, `do`.


File: gnuplot.info,  Node: load,  Next: lower,  Prev: iteration,  Up: Commands

3.12 load
=========

The `load` command executes each line of the specified input file as if
it had been typed in interactively.  Files created by the *note save::
command can later be `load`ed.  Any text file containing valid commands
can be created and then executed by the `load` command.  Files being
`load`ed may themselves contain `load` or *note call:: commands.  See
`comments` for information about comments in commands.  To `load` with
arguments, see *note call::.

   Syntax:
           load "<input-file>"

   The name of the input file must be enclosed in quotes.

   The special filename "-" may be used to `load` commands from
standard input.  This allows a `gnuplot` command file to accept some
commands from standard input.  Please see help for `batch/interactive`
for more details.

   On some systems which support a popen function (Unix), the load file
can be read from a pipe by starting the file name with a '<'.

   Examples:
           load 'work.gnu'
           load "func.dat"
           load "< loadfile_generator.sh"

   The `load` command is performed implicitly on any file names given as
arguments to `gnuplot`.  These are loaded in the order specified, and
then `gnuplot` exits.


File: gnuplot.info,  Node: lower,  Next: pause,  Prev: load,  Up: Commands

3.13 lower
==========

Syntax:
           lower {plot_window_nb}

   The *note lower:: command lowers (opposite to *note raise::) plot
window(s) associated with the interactive terminal of your gnuplot
session, i.e. `pm`, `win`, `wxt` or `x11`. It puts the plot window to
bottom in the z-order windows stack of the window manager of your
desktop.

   As `x11` and `wxt` support multiple plot windows, then by default
they lower these windows in descending order of most recently created
on top to the least recently created on bottom. If a plot number is
supplied as an optional parameter, only the associated plot window will
be lowered if it exists.

   The optional parameter is ignored for single plot-window terminals,
i.e. `pm` and `win`.


File: gnuplot.info,  Node: pause,  Next: plot,  Prev: lower,  Up: Commands

3.14 pause
==========

The *note pause:: command displays any text associated with the command
and then waits a specified amount of time or until the carriage return
is pressed.  *note pause:: is especially useful in conjunction with
`load` files.

   Syntax:
           pause <time> {"<string>"}
           pause mouse {<endcondition>}{, <endcondition>} {"<string>"}

   <time> may be any constant or expression.  Choosing -1 will wait
until a carriage return is hit, zero (0) won't pause at all, and a
positive number will wait the specified number of seconds.  The time is
rounded to an integer number of seconds if subsecond time resolution is
not supported by the given platform.  `pause 0` is synonymous with
*note print::.

   If the current terminal supports `mousing`, then `pause mouse` will
terminate on either a mouse click or on ctrl-C.  For all other
terminals, or if mousing is not active, `pause mouse` is equivalent to
`pause -1`.

   If one or more end conditions are given after `pause mouse`, then
any one of the conditions will terminate the pause. The possible end
conditions are `keypress`, `button1`, `button2`, `button3`, `close`,
and `any`.  If the pause terminates on a keypress, then the ascii value
of the key pressed is returned in MOUSE_KEY.  The character itself is
returned as a one character string in MOUSE_CHAR. Hotkeys (bind
command) are disabled if keypress is one of the end conditions.
Zooming is disabled if button3 is one of the end conditions.

   In all cases the coordinates of the mouse are returned in variables
MOUSE_X, MOUSE_Y, MOUSE_X2, MOUSE_Y2.  See *note variables::.

   Note: Since *note pause:: communicates with the operating system
rather than the graphics, it may behave differently with different
device drivers (depending upon how text and graphics are mixed).

   Examples:
           pause -1    # Wait until a carriage return is hit
           pause 3     # Wait three seconds
           pause -1  "Hit return to continue"
           pause 10  "Isn't this pretty?  It's a cubic spline."
           pause mouse "Click any mouse button on selected data point"
           pause mouse keypress "Type a letter from A-F in the active window"
           pause mouse button1,keypress
           pause mouse any "Any key or button will terminate"

   The variant "pause mouse key" will resume after any keypress in the
active plot window. If you want to wait for a particular key to be
pressed, you can use a reread loop such as:

           print "I will resume after you hit the Tab key in the plot window"
           load "wait_for_tab"

   File "wait_for_tab" contains the lines

           pause mouse key
           if (MOUSE_KEY != 9) reread


File: gnuplot.info,  Node: plot,  Next: print,  Prev: pause,  Up: Commands

3.15 plot
=========

`plot` is the primary command for drawing plots with `gnuplot`.  It
creates plots of functions and data in many, many ways.  `plot` is used
to draw 2D functions and data; `splot` draws 2D projections of 3D
surfaces and data.  `plot` and `splot` offer many features in common;
see `splot` for differences.  Note specifically that although the
`binary <binary list>` variation does work for both `plot` and `splot`,
there are small differences between them.

   Syntax:
           plot {<ranges>}
                {<iteration>}
                {<function> | {"<datafile>" {datafile-modifiers}}}
                {axes <axes>} {<title-spec>} {with <style>}
                {, {definitions{,}} <function> ...}

   where either a <function> or the name of a data file enclosed in
quotes is supplied.  A function is a mathematical expression or a pair
of mathematical expressions in parametric mode.  Functions may be
builtin, user-defined, or provided in the plot command itself.
Multiple datafiles and/or functions may be plotted in a single command,
separated by commas.  See `data`, *note functions::.

   Examples:
           plot sin(x)
           plot sin(x), cos(x)
           plot f(x) = sin(x*a), a = .2, f(x), a = .4, f(x)
           plot "datafile.1" with lines, "datafile.2" with points
           plot [t=1:10] [-pi:pi*2] tan(t), \
                "data.1" using (tan($2)):($3/$4) smooth csplines \
                         axes x1y2 notitle with lines 5
           plot for [datafile in "spinach.dat broccoli.dat"] datafile

   See also `show plot`.

* Menu:

* axes::
* binary::
* data::
* errorbars::
* errorlines::
* functions::
* parametric::
* ranges::
* iteration_::
* title::
* with::


File: gnuplot.info,  Node: axes,  Next: binary,  Prev: plot,  Up: plot

3.15.1 axes
-----------

There are four possible sets of axes available; the keyword <axes> is
used to select the axes for which a particular line should be scaled.
`x1y1` refers to the axes on the bottom and left; `x2y2` to those on
the top and right; `x1y2` to those on the bottom and right; and `x2y1`
to those on the top and left.  Ranges specified on the `plot` command
apply only to the first set of axes (bottom left).


File: gnuplot.info,  Node: binary,  Next: data,  Prev: axes,  Up: plot

3.15.2 binary
-------------

BINARY DATA FILES:

   Some earlier versions of `gnuplot` automatically detected binary
data files.  It is now necessary to provide the keyword *note binary::
after the filename.  Adequate details of the file format must be given
on the command line or extracted from the file itself for a supported
binary *note filetype::.  In particular, there are two structures for
binary files,  binary matrix format and binary general format.

   The *note matrix:: format contains a two dimensional array of 32 bit
IEEE float values with an additional column and row of coordinate
values.  As with ASCII matrix, in the *note using:: list, enumeration
of the coordinate row constitutes column 1, enumeration of the
coordinate column constitutes column 2, and the array of values
constitutes column 3.

   The *note general:: format contains an arbitrary number of columns
for which information must be specified at the command line.  For
example, *note array::, *note record::, `format` and *note using:: can
indicate the size, format and dimension of data.  There are a variety
of useful commands for skipping file headers and changing endianess.
There are a set of commands for positioning and translating data since
often coordinates are not part of the file when uniform sampling is
inherent in the data.  Different from matrix binary or ASCII, general
binary does not treat the generated columns as 1, 2 or 3 in the *note
using:: list.  Rather, column 1 begins with column 1 of the file, or as
specified in the `format` list.

   There are global default settings for the various binary options
which may be set using the same syntax as the options when used as part
of the `(s)plot <filename> binary ...` command.  This syntax is `set
datafile binary ...`.  The general rule is that common command-line
specified parameters override file-extracted parameters which override
default parameters.

   *note matrix:: is the default binary format when no keywords
specific to *note general:: are given, i.e., *note array::, *note
record::, `format`, *note filetype::.

   General binary data can be entered at the command line via the
special file name '-'.  However, this is intended for use through a
pipe where programs can exchange binary data, not for keyboards.  There
is no "end of record" character for binary data.  Gnuplot continues
reading from a pipe until it has read the number of points declared in
the *note array:: qualifier.  See *note matrix:: or *note general:: for
more details.

   The *note index:: keyword is not supported, since the file format
allows only one surface per file.  The *note every:: and *note using::
filters are supported.  *note using:: operates as if the data were read
in the above triplet form.  Binary File Splot Demo.
(http://www.gnuplot.info/demo/binary.html)

* Menu:

* general::
* array::
* record::
* skip::
* format::
* endian::
* filetype::
* keywords::


File: gnuplot.info,  Node: general,  Next: array,  Prev: binary,  Up: binary

3.15.2.1 general
................

General binary data in which format information is not necessarily part
of the file can be read by giving further details about the file format
at the command line.  Although the syntax is slightly arcane to the
casual user, general binary is particularly useful for application
programs using gnuplot and sending large amounts of data.

   Syntax:
           plot '<file_name>' {binary <binary list>} ...
           splot '<file_name>' {binary <binary list>} ...

   General binary format is activated by keywords in <binary list>
pertaining to information about file structure, i.e., *note array::,
*note record::, `format` or *note filetype::.  Otherwise, matrix binary
format is assumed.  (See *note matrix:: for more details.)

   There are some standard file types that may be read for which
details about the binary format may be extracted automatically.  (Type
*note binary:: at the command line for a list.)  Otherwise, details
must be specified at the command line or set in the defaults.  Keywords
are described below.

   The keyword *note filetype:: in <binary list> controls the routine
used to read the file, i.e., the format of the data.  For a list of the
supported file types, type `show datafile binary filetypes`.  If no
file type is given, the rule is that traditional gnuplot binary is
assumed for `splot` if the *note binary:: keyword stands alone.  In all
other circumstances, for `plot` or when one of the <binary list>
keywords appears, a raw binary file is assumed whereby the keywords
specify the binary format.

   General binary data files fall into two basic classes, and some
files may be of both classes depending upon how they are treated.
There is that class for which uniform sampling is assumed and point
coordinates must be generated.  This is the class for which full
control via the <binary list> keywords applies.  For this class, the
settings precedence is that command line parameters override in-file
parameters, which override default settings.  The other class is that
set of files for which coordinate information is contained within the
file or there is possibly a non-uniform sampling such as gnuplot binary.

   Other than for the unique data files such as gnuplot binary, one
should think of binary data as conceptually the same as ASCII data.
Each point has columns of information which are selected via the
`<using list>` associated with *note using::.  When no `format` string
is specified, gnuplot will retrieve a number of binary variables equal
to the largest column given in the `<using list>`.  For example, `using
1:3` will result in three columns being read, of which the second will
be ignored.  There are default using lists based upon the typical
number of parameters associated with a certain plot type.  For example,
`with image` has a default of `using 1`, while *note rgbimage:: has a
default of `using 1:2:3`.  Note that the special characters for *note
using:: representing point/line/index generally should not be used for
binary data.  There are keywords in <binary list> that control this.


File: gnuplot.info,  Node: array,  Next: record,  Prev: general,  Up: binary

3.15.2.2 array
..............

Describes the sampling array dimensions associated with the binary file.
The coordinates will be generated by gnuplot.  A number must be
specified for each dimension of the array.  For example,
`array=(10,20)` means the underlying sampling structure is
two-dimensional with 10 points along the first (x) dimension and 20
points along the second (y) dimension.  A negative number indicates
that data should be read until the end of file.  If there is only one
dimension, the parentheses may be omitted.  A colon can be used to
separate the dimensions for multiple records.  For example,
`array=25:35` indicates there are two one-dimensional records in the
file.
           Note:  Gnuplot version 4.2 used the syntax array=128x128 rather than
                  array=(128,128). The older syntax is now deprecated, but may
                  still work if your copy of gnuplot was built to support
                  backwards compatibility.


File: gnuplot.info,  Node: record,  Next: skip,  Prev: array,  Up: binary

3.15.2.3 record
...............

This keyword serves the same function as *note array::, having the same
syntax.  However, *note record:: causes gnuplot to not generate
coordinate information.  This is for the case where such information
may be included in one of the columns of the binary data file.


File: gnuplot.info,  Node: skip,  Next: format,  Prev: record,  Up: binary

3.15.2.4 skip
.............

This keyword allows you to skip sections of a binary file. For
instance, if the file contains a 1024 byte header before the start of
the data region you would probably want to use
           plot '<file_name>' binary skip=1024 ...

   If there are multiple records in the file, you may specify a leading
offset for each. For example, to skip 512 bytes before the 1st record
and 256 bytes before the second and third records
           plot '<file_name> binary record=356:356:356 skip=512:256:256 ...


File: gnuplot.info,  Node: format,  Next: endian,  Prev: skip,  Up: binary

3.15.2.5 format
...............

The default binary format is a float.  For more flexibility, the format
can include details about variable sizes.  For example,
`format="%uchar%int%float"` associates an unsigned character with the
first using column, an int with the second column and a float with the
third column.  If the number of size specifications is less than the
greatest column number, the size is implicitly taken to be similar to
the last given variable size.

   Furthermore, similar to the *note using:: specification, the format
can include discarded columns via the `*` character and have implicit
repetition via a numerical repeat-field.  For example,
`format="%*2int%3float"` causes gnuplot to discard two ints before
reading three floats.  To list variable sizes, type `show datafile
binary datasizes`.  There are a group of names that are machine
dependent along with their sizes in bytes for the particular
compilation.  There is also a group of names which attempt to be
machine independent.


File: gnuplot.info,  Node: endian,  Next: filetype,  Prev: format,  Up: binary

3.15.2.6 endian
...............

Often the endianess of binary data in the file does not agree with the
endianess used by the platform on which gnuplot is running.  Several
words can direct gnuplot how to arrange bytes.  For example
`endian=little` means treat the binary file as having byte significance
from least to greatest. The options are

                   little:  least significant to greatest significance
                      big:  greatest significance to least significance
                  default:  assume file endianess is the same as compiler
              swap (swab):  Interchange the significance.  (If things
                            don't look right, try this.)

   Gnuplot can support "middle" ("pdp") endian if it is compiled with
that option.


File: gnuplot.info,  Node: filetype,  Next: keywords,  Prev: endian,  Up: binary

3.15.2.7 filetype
.................

For some standard binary file formats gnuplot can extract all the
necessary information from the file in question.  As an example,
"format=edf" will read ESRF Header File format files.  For a list of
the currently supported file formats, type `show datafile binary
filetypes`.

   There is a special file type called `auto` for which gnuplot will
check if the binary file's extension is a quasi-standard extension for
a supported format.

   Command line keywords may be used to override settings extracted
from the file.  The settings from the file override any defaults.  (See
*note binary:: for details.)

-- AVS --

   `avs` is one of the automatically recognized binary file types for
images.  AVS is an extremely simple format, suitable mostly for
streaming between applications. It consists of 2 longs (xwidth, ywidth)
followed by a stream of pixels, each with four bytes of information
alpha/red/green/blue.

-- EDF --

   `edf` is one of the automatically recognized binary file types for
images.  EDF stands for ESRF Data Format, and it supports both edf and
ehf formats (the latter means ESRF Header Format).  More information on
specifications can be found at

       http://www.edfplus.info/specs

-- PNG --

   If gnuplot was configured to use the libgd library for png/gif/jpeg
output, then it can also be used to read these same image types as
binary files.  You can use an explicit command
           plot 'file.png' binary filetype=png

   Or the file type will be recognized automatically from the extension
if you have previously requested
           set datafile binary filetype=auto


File: gnuplot.info,  Node: keywords,  Prev: filetype,  Up: binary

3.15.2.8 keywords
.................

The following keywords apply only when generating coordinates from
binary data files.  That is, the control mapping the individual
elements of a binary array, matrix, or image to specific x/y/z
positions.

-- SCAN --

   A great deal of confusion can arise concerning the relationship
between how gnuplot scans a binary file and the dimensions seen on the
plot.  To lessen the confusion, conceptually think of gnuplot _always_
scanning the binary file point/line/plane or fast/medium/slow.  Then
this keyword is used to tell gnuplot how to map this scanning
convention to the Cartesian convention shown in plots, i.e., x/y/z.
The qualifier for scan is a two or three letter code representing where
point is assigned (first letter), line is assigned (second letter), and
plane is assigned (third letter).  For example, `scan=yx` means the
fastest, point-by-point, increment should be mapped along the Cartesian
y dimension and the middle, line-by-line, increment should be mapped
along the x dimension.

   When the plotting mode is `plot`, the qualifier code can include the
two letters x and y.  For `splot`, it can include the three letters x,
y and z.

   There is nothing restricting the inherent mapping from
point/line/plane to apply only to Cartesian coordinates.  For this
reason there are cylindrical coordinate synonyms for the qualifier
codes where t (theta), r and z are analogous to the x, y and z of
Cartesian coordinates.

-- TRANSPOSE --

   Shorthand notation for `scan=yx` or `scan=yxz`.

-- DX, DY, DZ --

   When gnuplot generates coordinates, it uses the spacing described by
these keywords.  For example `dx=10 dy=20` would mean space samples
along the x dimension by 10 and space samples along the y dimension by
20.  `dy` cannot appear if `dx` does not appear.  Similarly, `dz`
cannot appear if `dy` does not appear.  If the underlying dimensions
are greater than the keywords specified, the spacing of the highest
dimension given is extended to the other dimensions.  For example, if
an image is being read from a file and only `dx=3.5` is given gnuplot
uses a delta x and delta y of 3.5.

   The following keywords also apply only when generating coordinates.
However they may also be used with matrix binary files.

-- FLIPX, FLIPY, FLIPZ --

   Sometimes the scanning directions in a binary datafile are not
consistent with that assumed by gnuplot.  These keywords can flip the
scanning direction along dimensions x, y, z.

-- ORIGIN  --

   When gnuplot generates coordinates based upon transposition and
flip, it attempts to always position the lower left point in the array
at the origin, i.e., the data lies in the first quadrant of a Cartesian
system after transpose and flip.

   To position the array somewhere else on the graph, the *note
origin:: keyword directs gnuplot to position the lower left point of
the array at a point specified by a tuple.  The tuple should be a
double for `plot` and a triple for `splot`.  For example,
`origin=(100,100):(100,200)` is for two records in the file and
intended for plotting in two dimensions. A second example,
`origin=(0,0,3.5)`, is for plotting in three dimensions.

-- CENTER --

   Similar to *note origin::, this keyword will position the array such
that its center lies at the point given by the tuple.  For example,
`center=(0,0)`.  Center does not apply when the size of the array is
`Inf`.

-- ROTATE --

   The transpose and flip commands provide some flexibility in
generating and orienting coordinates.  However, for full degrees of
freedom, it is possible to apply a rotational vector described by a
rotational angle in two dimensions.

   The `rotate` keyword applies to the two-dimensional plane, whether
it be `plot` or `splot`.  The rotation is done with respect to the
positive angle of the Cartesian plane.

   The angle can be expressed in radians, radians as a multiple of pi,
or degrees.  For example, `rotate=1.5708`, `rotate=0.5pi` and
`rotate=90deg` are equivalent.

   If *note origin:: is specified, the rotation is done about the lower
left sample point before translation.  Otherwise, the rotation is done
about the array `center`.

-- PERPENDICULAR --

   For `splot`, the concept of a rotational vector is implemented by a
triple representing the vector to be oriented normal to the
two-dimensional x-y plane.  Naturally, the default is (0,0,1).  Thus
specifying both rotate and perpendicular together can orient data
myriad ways in three-space.

   The two-dimensional rotation is done first, followed by the
three-dimensional rotation.  That is, if R' is the rotational 2 x 2
matrix described by an angle, and P is the 3 x 3 matrix projecting
(0,0,1) to (xp,yp,zp), let R be constructed from R' at the upper left
sub-matrix, 1 at element 3,3 and zeros elsewhere.  Then the matrix
formula for translating data is v' = P R v, where v is the 3 x 1 vector
of data extracted from the data file.  In cases where the data of the
file is inherently not three-dimensional, logical rules are used to
place the data in three-space.  (E.g., usually setting the z-dimension
value to zero and placing 2D data in the x-y plane.)


File: gnuplot.info,  Node: data,  Next: errorbars,  Prev: binary,  Up: plot

3.15.3 data
-----------

Discrete data contained in a file can be displayed by specifying the
name of the data file (enclosed in single or double quotes) on the
`plot` command line.

   Syntax:
           plot '<file_name>' {binary <binary list>}
                              {{nonuniform} matrix}
                              {index <index list> | index "<name>"}
                              {every <every list>}
                              {thru <thru expression>}
                              {using <using list>}
                              {smooth <option>}
                              {volatile} {noautoscale}

   The modifiers *note binary::, *note index::, *note every::, *note
thru::, *note using::, and *note smooth:: are discussed separately.  In
brief, *note binary:: allows data entry from a binary file (default is
ASCII), *note index:: selects which data sets in a multi-data-set file
are to be plotted, *note every:: specifies which points within a single
data set are to be plotted, *note using:: determines how the columns
within a single record are to be interpreted (*note thru:: is a special
case of *note using::), and *note smooth:: allows for simple
interpolation and approximation.  (`splot` has a similar syntax, but
does not support the *note smooth:: and *note thru:: options.)

   The `noautoscale` keyword means that the points making up this plot
will be ignored when automatically determining axis range limits.

   ASCII DATA FILES:

   Data files should contain at least one data point per record (*note
using:: can select one data point from the record). Records beginning
with `#` (and also with `!` on VMS) will be treated as comments and
ignored.  Each data point represents an (x,y) pair. For `plot`s with
error bars or error bars with lines (see *note errorbars:: or *note
errorlines::), each data point is (x,y,ydelta), (x,y,ylow,yhigh),
(x,y,xdelta), (x,y,xlow,xhigh), or (x,y,xlow,xhigh,ylow,yhigh).

   In all cases, the numbers of each record of a data file must be
separated by white space (one or more blanks or tabs) unless a format
specifier is provided by the *note using:: option. This white space
divides each record into columns. However, whitespace inside a pair of
double quotes is ignored when counting columns, so the following
datafile line has three columns:
           1.0 "second column" 3.0

   Data may be written in exponential format with the exponent preceded
by the letter e or E.  The fortran exponential specifiers d, D, q, and
Q may also be used if the command `set datafile fortran` is in effect.

   Only one column (the y value) need be provided.  If x is omitted,
`gnuplot` provides integer values starting at 0.

   In datafiles, blank records (records with no characters other than
blanks and a newline and/or carriage return) are significant.

   Single blank records designate discontinuities in a `plot`; no line
will join points separated by a blank records (if they are plotted with
a line style).

   Two blank records in a row indicate a break between separate data
sets.  See *note index::.

   If autoscaling has been enabled (*note autoscale::), the axes are
automatically extended to include all datapoints, with a whole number
of tic marks if tics are being drawn.  This has two consequences: i)
For `splot`, the corner of the surface may not coincide with the corner
of the base.  In this case, no vertical line is drawn.  ii) When
plotting data with the same x range on a dual-axis graph, the x
coordinates may not coincide if the x2tics are not being drawn.  This
is because the x axis has been autoextended to a whole number of tics,
but the x2 axis has not.  The following example illustrates the problem:

           reset; plot '-', '-' axes x2y1
           1 1
           19 19
           e
           1 1
           19 19
           e

   To avoid this, you can use the `fixmin`/`fixmax` feature of the
*note autoscale:: command, which turns off the automatic extension of
the axis range up to the next tic mark.

   Label coordinates and text can also be read from a data file (see
*note labels::).

* Menu:

* every::
* example_datafile::
* index::
* smooth::
* special-filenames::
* thru::
* using::
* volatile::


File: gnuplot.info,  Node: every,  Next: example_datafile,  Prev: data,  Up: data

3.15.3.1 every
..............

The *note every:: keyword allows a periodic sampling of a data set to
be plotted.

   In the discussion a "point" is a datum defined by a single record in
the file; "block" here will mean the same thing as "datablock" (see
`glossary`).

   Syntax:
           plot 'file' every {<point_incr>}
                               {:{<block_incr>}
                                 {:{<start_point>}
                                   {:{<start_block>}
                                     {:{<end_point>}
                                       {:<end_block>}}}}}

   The data points to be plotted are selected according to a loop from
<`start_point`> to <`end_point`> with increment <`point_incr`> and the
blocks according to a loop from <`start_block`> to <`end_block`> with
increment <`block_incr`>.

   The first datum in each block is numbered '0', as is the first block
in the file.

   Note that records containing unplottable information are counted.

   Any of the numbers can be omitted; the increments default to unity,
the start values to the first point or block, and the end values to the
last point or block.  If *note every:: is not specified, all points in
all lines are plotted.

   Examples:
           every :::3::3    # selects just the fourth block ('0' is first)
           every :::::9     # selects the first 10 blocks
           every 2:2        # selects every other point in every other block
           every ::5::15    # selects points 5 through 15 in each block

   See simple plot demos (simple.dem)
(http://www.gnuplot.info/demo/simple.html) , Non-parametric splot demos
(http://www.gnuplot.info/demo/surface1.html) , and Parametric splot
demos (http://www.gnuplot.info/demo/surface2.html) .


File: gnuplot.info,  Node: example_datafile,  Next: index,  Prev: every,  Up: data

3.15.3.2 example datafile
.........................

This example plots the data in the file "population.dat" and a
theoretical curve:

           pop(x) = 103*exp((1965-x)/10)
           set xrange [1960:1990]
           plot 'population.dat', pop(x)

   The file "population.dat" might contain:

           # Gnu population in Antarctica since 1965
              1965   103
              1970   55
              1975   34
              1980   24
              1985   10

   Binary examples:

           # Selects two float values (second one implicit) with a float value
           # discarded between them for an indefinite length of 1D data.
           plot '<file_name>' binary format="%float%*float" using 1:2 with lines

           # The data file header contains all details necessary for creating
           # coordinates from an EDF file.
           plot '<file_name>' binary filetype=edf with image
           plot '<file_name>.edf' binary filetype=auto with image

           # Selects three unsigned characters for components of a raw RGB image
           # and flips the y-dimension so that typical image orientation (start
           # at top left corner) translates to the Cartesian plane.  Pixel
           # spacing is given and there are two images in the file.  One of them
           # is translated via origin.
           plot '<file_name>' binary array=(512,1024):(1024,512) format='%uchar' \
                dx=2:1 dy=1:2 origin=(0,0):(1024,1024) flipy u 1:2:3 w rgbimage

           # Four separate records in which the coordinates are part of the
           # data file.  The file was created with a endianess different from
           # the system on which gnuplot is running.
           splot '<file_name>' binary record=30:30:29:26 endian=swap u 1:2:3

           # Same input file, but this time we skip the 1st and 3rd records
           splot '<file_name>' binary record=30:26 skip=360:348 endian=swap u 1:2:3

   See also *note matrix::.


File: gnuplot.info,  Node: index,  Next: smooth,  Prev: example_datafile,  Up: data

3.15.3.3 index
..............

The *note index:: keyword allows you to select specific data sets in a
multi-data-set file for plotting.

   Syntax:
           plot 'file' index { <m>{:<n>{:<p>}} | "<name>" }

   Data sets are separated by pairs of blank records.  `index <m>`
selects only set <m>; `index <m>:<n>` selects sets in the range <m> to
<n>; and `index <m>:<n>:<p>` selects indices <m>, <m>+<p>, <m>+2<p>,
etc., but stopping at <n>.  Following C indexing, the index 0 is
assigned to the first data set in the file.  Specifying too large an
index results in an error message.  If <p> is specified but <n> is left
blank then every <p>-th dataset is read until the end of the file.  If
*note index:: is not specified, the entire file is plotted as a single
data set.

   Example:
           plot 'file' index 4:5

   For each point in the file, the index value of the data set it
appears in is available via the pseudo-column `column(-2)`.  This leads
to an alternative way of distinguishing individual data sets within a
file as shown below.  This is more awkward than the *note index::
command if all you are doing is selecting one data set for plotting,
but is very useful if you want to assign different properties to each
data set.  See `pseudocolumns`, `lc variable`.

   Example:
           plot 'file' using 1:(column(-2)==4 ? $2 : NaN)        # very awkward
           plot 'file' using 1:2:(column(-2)) linecolor variable # very useful!

   `index '<name>'` selects the data set with name '<name>'.  Names are
assigned to data sets in comment lines.  The comment character and
leading white space are removed from the comment line.  If the
resulting line starts with <name>, the following data set is now named
<name> and can be selected.

   Example:
           plot 'file' index 'Population'

   Please note that every comment that starts with <name> will name the
following data set.  To avoid problems it may be useful to choose a
naming scheme like '== Population ==' or '[Population]'.

   splot with indices demo.
(http://www.gnuplot.info/demo/multimsh.html)</p>


File: gnuplot.info,  Node: smooth,  Next: special-filenames,  Prev: index,  Up: data

3.15.3.4 smooth
...............

`gnuplot` includes a few general-purpose routines for interpolation and
approximation of data; these are grouped under the *note smooth::
option.  More sophisticated data processing may be performed by
preprocessing the data externally or by using *note fit:: with an
appropriate model.

   Syntax:
           smooth {unique | frequency | cumulative | cnormal | kdensity
                          | csplines | acsplines | bezier | sbezier}

   `unique`, `frequency`, `cumulative` and `cnormal` plot the data after
making them monotonic.  Each of the other routines uses the data to
determine the coefficients of a continuous curve between the endpoints
of the data.  This curve is then plotted in the same manner as a
function, that is, by finding its value at uniform intervals along the
abscissa (see *note samples::) and connecting these points with straight
line segments (if a line style is chosen).

   If *note autoscale:: is in effect, the ranges will be computed such
that the plotted curve lies within the borders of the graph.

   If *note autoscale:: is not in effect, and the smooth option is
either `acspline` or `cspline`, the sampling of the generated curve is
done across the intersection of the x range covered by the input data
and the fixed abscissa range as defined by *note xrange::.

   If too few points are available to allow the selected option to be
applied, an error message is produced.  The minimum number is one for
`unique` and `frequency`, four for `acsplines`, and three for the
others.

   The *note smooth:: options have no effect on function plots.

-- ACSPLINES --

   The `acsplines` option approximates the data with a "natural
smoothing spline".  After the data are made monotonic in x (see `smooth
unique`), a curve is piecewise constructed from segments of cubic
polynomials whose coefficients are found by the weighting the data
points; the weights are taken from the third column in the data file.
That default can be modified by the third entry in the *note using::
list, e.g.,
           plot 'data-file' using 1:2:(1.0) smooth acsplines

   Qualitatively, the absolute magnitude of the weights determines the
number of segments used to construct the curve.  If the weights are
large, the effect of each datum is large and the curve approaches that
produced by connecting consecutive points with natural cubic splines.
If the weights are small, the curve is composed of fewer segments and
thus is smoother; the limiting case is the single segment produced by a
weighted linear least squares fit to all the data.  The smoothing
weight can be expressed in terms of errors as a statistical weight for
a point divided by a "smoothing factor" for the curve so that
(standard) errors in the file can be used as smoothing weights.

   Example:
           sw(x,S)=1/(x*x*S)
           plot 'data_file' using 1:2:(sw($3,100)) smooth acsplines

-- BEZIER --

   The `bezier` option approximates the data with a Bezier curve of
degree n (the number of data points) that connects the endpoints.

-- CSPLINES --

   The `csplines` option connects consecutive points by natural cubic
splines after rendering the data monotonic (see `smooth unique`).

-- SBEZIER --

   The `sbezier` option first renders the data monotonic (`unique`) and
then applies the `bezier` algorithm.

-- UNIQUE --

   The `unique` option makes the data monotonic in x; points with the
same x-value are replaced by a single point having the average y-value.
The resulting points are then connected by straight line segments.

-- FREQUENCY --

   The `frequency` option makes the data monotonic in x; points with
the same x-value are replaced by a single point having the summed
y-values.  The resulting points are then connected by straight line
segments.  See also smooth.dem
(http://www.gnuplot.info/demo/smooth.html)

-- CUMULATIVE --

   The `cumulative` option makes the data monotonic in x; points with
the same x-value are replaced by a single point containing the
cumulative sum of y-values of all data points with lower x-values (i.e.
to the left of the current data point). This can be used to obtain a
cumulative distribution function from data.  See also smooth.dem
(http://www.gnuplot.info/demo/smooth.html)

-- CNORMAL --

   The `cnormal` option makes the data monotonic in x and normalises the
y-values onto the range [0:1].  Points with the same x-value are
replaced by a single point containing the cumulative sum of y-values of
all data points with lower x-values (i.e. to the left of the current
data point) divided by the total sum of all y-values. This can be used
to obtain a normalised cumulative distribution function from data
(useful when comparing sets of samples with differing numbers of
members).  See also smooth.dem
(http://www.gnuplot.info/demo/smooth.html)

-- KDENSITY --

   The `kdensity` option is a way to plot a kernel density estimate
(which is a smooth histogram) for a random collection of points, using
Gaussian kernels.  A Gaussian is placed at the location of each point
in the first column and the sum of all these Gaussians is plotted as a
function. The value in the second column is taken as weight of the
Gaussian. (To obtain a normalized histogram, this should be
1/number-of-points). The value of the third column, if supplied, is
taken as the bandwidth for the kernels. If only two columns have been
specified, or if the value of the third column is zero or less, gnuplot
calculates the bandwidth which would be optimal if the input data was
normally distributed. (This will usually be a very conservative, i.e.
broad bandwidth.)


File: gnuplot.info,  Node: special-filenames,  Next: thru,  Prev: smooth,  Up: data

3.15.3.5 special-filenames
..........................

There are a few filenames that have a special meaning:  ", '-', '+' and
'++'.

   The empty filename " tells gnuplot to re-use the previous input file
in the same plot command. So to plot two columns from the same input
file:

           plot 'filename' using 1:2, '' using 1:3

   The special filenames '+' and '++' are a mechanism to allow the full
range of *note using:: specifiers and plot styles with in-line
functions.  Normally a function plot can only have a single y (or z)
value associated with each sampled point.  The pseudo-file '+' treats
the sampled points as column 1, and allows additional column values to
be specified via a *note using:: specification, just as for a true
input file.  The number of samples returned is controlled by *note
samples::.  Example:

           plot '+' using ($1):(sin($1)):(sin($1)**2) with filledcurves

   Similarly the pseudo-file '++' returns 2 columns of data forming a
regular grid of [x,y] coordinates with the number of points along x
controlled by *note samples:: and the number of points along y
controlled by *note isosamples::.  You must set xrange and yrange
before plotting '++'.  Examples:

           splot '++' using 1:2:(sin($1)*sin($2)) with pm3d
           plot '++' using 1:2:(sin($1)*sin($2)) with image

   The special filename `'-'` specifies that the data are inline; i.e.,
they follow the command.  Only the data follow the command; `plot`
options like filters, titles, and line styles remain on the `plot`
command line.  This is similar to << in unix shell script, and $DECK in
VMS DCL.  The data are entered as though they are being read from a
file, one data point per record.  The letter "e" at the start of the
first column terminates data entry.  The *note using:: option can be
applied to these data--using it to filter them through a function might
make sense, but selecting columns probably doesn't!

   `'-'` is intended for situations where it is useful to have data and
commands together, e.g., when `gnuplot` is run as a sub-process of some
front-end application.  Some of the demos, for example, might use this
feature.  While `plot` options such as *note index:: and *note every::
are recognized, their use forces you to enter data that won't be used.
For example, while

           plot '-' index 0, '-' index 1
           2
           4
           6

           10
           12
           14
           e
           2
           4
           6

           10
           12
           14
           e

   does indeed work,

           plot '-', '-'
           2
           4
           6
           e
           10
           12
           14
           e

   is a lot easier to type.

   If you use `'-'` with *note replot::, you may need to enter the data
more than once.  See *note replot::, *note refresh::.

   A blank filename (") specifies that the previous filename should be
reused.  This can be useful with things like

           plot 'a/very/long/filename' using 1:2, '' using 1:3, '' using 1:4

   (If you use both `'-'` and `"` on the same `plot` command, you'll
need to have two sets of inline data, as in the example above.)

   On systems with a popen function, the datafile can be piped through
a shell command by starting the file name with a '<'.  For example,

           pop(x) = 103*exp(-x/10)
           plot "< awk '{print $1-1965, $2}' population.dat", pop(x)

   would plot the same information as the first population example but
with years since 1965 as the x axis.  If you want to execute this
example, you have to delete all comments from the data file above or
substitute the following command for the first part of the command
above (the part up to the comma):

           plot "< awk '$0 !~ /^#/ {print $1-1965, $2}' population.dat"

   While this approach is most flexible, it is possible to achieve
simple filtering with the *note using:: or *note thru:: keywords.


File: gnuplot.info,  Node: thru,  Next: using,  Prev: special-filenames,  Up: data

3.15.3.6 thru
.............

The *note thru:: function is provided for backward compatibility.

   Syntax:
           plot 'file' thru f(x)

   It is equivalent to:

           plot 'file' using 1:(f($2))

   While the latter appears more complex, it is much more flexible.
The more natural

           plot 'file' thru f(y)

   also works (i.e. you can use y as the dummy variable).

   *note thru:: is parsed for `splot` and *note fit:: but has no effect.


File: gnuplot.info,  Node: using,  Next: volatile,  Prev: thru,  Up: data

3.15.3.7 using
..............

The most common datafile modifier is *note using::.  It tells the
program which columns of data in the input file are to be plotted.

   Syntax:
           plot 'file' using <entry> {:<entry> {:<entry> ...}} {'format'}

   If a format is specified, it is used to read in each datafile record
using the C library 'scanf' function.  Otherwise the record is
interpreted as consisting of columns (fields) of data separated by
whitespace (spaces and/or tabs), but see `datafile separator`.

   Each <entry> may be a simple column number that selects the value
from one field of the input file, a string that matches a column label
in the first line of a data set, an expression enclosed in parentheses,
or a special function not enclosed in parentheses such as xticlabels(2).

   If the entry is an expression in parentheses, then the function
column(N) may be used to indicate the value in column N. That is,
column(1) refers to the first item read, column(2) to the second, and
so on.  The special symbols $1, $2, ... are shorthand for column(1),
column(2) ...  The function `valid(N)` tests whether the value in the
Nth column is a valid number.  

   If each column of data in the input file contains a label in the
first row rather than a data value, this label can be used to identify
the column on input and/or in the plot legend. The column() function
can be used to select an input column by label rather than by column
number.  For example, if the data file contains
           Height    Weight    Age
           val1      val1      val1
           ...       ...       ...

   then the following plot commands are all equivalent
           plot 'datafile' using 3:1, '' using 3:2
           plot 'datafile' using (column("Age")):(column(1)), \
                        '' using (column("Age")):(column(2))
           plot 'datafile' using "Age":"Height", '' using "Age":"Weight"

   To use the column labels in the plot legend, use *note columnhead::.

   In addition to the actual columns 1...N in the input data file,
gnuplot presents data from several "pseudo-columns" that hold
bookkeeping information.  E.g. $0 or column(0) returns the sequence
number of this data record within a dataset.  Please see
`pseudocolumns`.

   An empty <entry> will default to its order in the list of entries.
For example, `using ::4` is interpreted as `using 1:2:4`.

   If the *note using:: list has only a single entry, that <entry> will
be used for y and the data point number (pseudo-column $0) is used for
x; for example, "`plot 'file' using 1`" is identical to "`plot 'file'
using 0:1`".  If the *note using:: list has two entries, these will be
used for x and y.  See *note style:: and *note fit:: for details about
plotting styles that make use of data from additional columns of input.

   'scanf' accepts several numerical specifications but `gnuplot`
requires all inputs to be double-precision floating-point variables, so
"%lf" is essentially the only permissible specifier.  A format string
given by the user must contain at least one such input specifier, and
no more than seven of them.  'scanf' expects to see white space--a
blank, tab ("\t"), newline ("\n"), or formfeed ("\f")--between numbers;
anything else in the input stream must be explicitly skipped.

   Note that the use of "\t", "\n", or "\f" requires use of
double-quotes rather than single-quotes.

-- USING_EXAMPLES --

   This creates a plot of the sum of the 2nd and 3rd data against the
first: The format string specifies comma- rather than space-separated
columns.  The same result could be achieved by specifying `set datafile
separator ","`.
           plot 'file' using 1:($2+$3) '%lf,%lf,%lf'

   In this example the data are read from the file "MyData" using a more
complicated format:
           plot 'MyData' using "%*lf%lf%*20[^\n]%lf"

   The meaning of this format is:

           %*lf        ignore a number
           %lf         read a double-precision number (x by default)
           %*20[^\n]   ignore 20 non-newline characters
           %lf         read a double-precision number (y by default)

   One trick is to use the ternary `?:` operator to filter data:

           plot 'file' using 1:($3>10 ? $2 : 1/0)

   which plots the datum in column two against that in column one
provided the datum in column three exceeds ten.  `1/0` is undefined;
`gnuplot` quietly ignores undefined points, so unsuitable points are
suppressed.  Or you can use the pre-defined variable NaN to achieve the
same result.  

   In fact, you can use a constant expression for the column number,
provided it doesn't start with an opening parenthesis; constructs like
`using 0+(complicated expression)` can be used.  The crucial point is
that the expression is evaluated once if it doesn't start with a left
parenthesis, or once for each data point read if it does.

   If timeseries data are being used, the time can span multiple
columns.  The starting column should be specified.  Note that the
spaces within the time must be included when calculating starting
columns for other data.  E.g., if the first element on a line is a time
with an embedded space, the y value should be specified as column three.

   It should be noted that `plot 'file'`, `plot 'file' using 1:2`, and
`plot 'file' using ($1):($2)` can be subtly different: 1) if `file` has
some lines with one column and some with two, the first will invent x
values when they are missing, the second will quietly ignore the lines
with one column, and the third will store an undefined value for lines
with one point (so that in a plot with lines, no line joins points
across the bad point); 2) if a line contains text at the first column,
the first will abort the plot on an error, but the second and third
should quietly skip the garbage.

   In fact, it is often possible to plot a file with lots of lines of
garbage at the top simply by specifying

           plot 'file' using 1:2

   However, if you want to leave text in your data files, it is safer
to put the comment character (#) in the first column of the text lines.

-- PSEUDOCOLUMNS --

   Expressions in the *note using:: clause of a plot statement can
refer to additional bookkeeping values in addition to the actual data
values contained in the input file. These are contained in
"pseudocolumns".
           column(0)   The sequential order of each point within a data set.
                       The counter starts at 0 and is reset by two sequential blank
                       records.  The shorthand form $0 is available.
           column(-1)  This counter starts at 0 and is reset by a single blank line.
                       This corresponds to the data line in array or grid data.
           column(-2)  The index number of the current data set within a file that
                       contains multiple data sets.  See *note index::.

-- XTICLABELS --

   Axis tick labels can be generated via a string function, usually
taking a data column as an argument. The simplest form uses the data
column itself as a string. That is,  xticlabels(N) is shorthand for
xticlabels(stringcolumn(N)).  This example uses the contents of column
3 as x-axis tick labels.

           plot 'datafile' using <xcol>:<ycol>:xticlabels(3) with <plotstyle>

   Axis tick labels may be generated for any of the plot axes: x x2 y
y2 z.  The `ticlabels(<labelcol>)` specifiers must come after all of
the data coordinate specifiers in the *note using:: portion of the
command.  For each data point which has a valid set of X,Y[,Z]
coordinates, the string value given to xticlabels() is added to the
list of xtic labels at the same X coordinate as the point it belongs
to. `xticlabels()` may be shortened to `xtic()` and so on.

   Example:

           splot "data" using 2:4:6:xtic(1):ytic(3):ztic(6)

   In this example the x and y axis tic labels are taken from different
columns than the x and y coordinate values. The z axis tics, however,
are generated from the z coordinate of the corresponding point.

   Example:

           plot "data" using 1:2:xtic( $3 > 10. ? "A" : "B" )

   This example shows the use of a string-valued function to generate
x-axis tick labels. Each point in the data file generates a tick mark
on x labeled either "A" or "B" depending on the value in column 3.

-- X2TICLABELS --

   See `plot using xticlabels`.

-- YTICLABELS --

   See `plot using xticlabels`.

-- Y2TICLABELS --

   See `plot using xticlabels`.

-- ZTICLABELS --

   See `plot using xticlabels`.


File: gnuplot.info,  Node: volatile,  Prev: using,  Up: data

3.15.3.8 volatile
.................

The *note volatile:: keyword in a plot command indicates that the data
previously read from the input stream or file may not be available for
re-reading.  This tells the program to use *note refresh:: rather than
*note replot:: commands whenever possible.  See *note refresh::.


File: gnuplot.info,  Node: errorbars,  Next: errorlines,  Prev: data,  Up: plot

3.15.4 errorbars
----------------

Error bars are supported for 2D data file plots by reading one to four
additional columns (or *note using:: entries); these additional values
are used in different ways by the various errorbar styles.

   In the default situation, `gnuplot` expects to see three, four, or
six numbers on each line of the data file--either

           (x, y, ydelta),
           (x, y, ylow, yhigh),
           (x, y, xdelta),
           (x, y, xlow, xhigh),
           (x, y, xdelta, ydelta), or
           (x, y, xlow, xhigh, ylow, yhigh).

   The x coordinate must be specified.  The order of the numbers must be
exactly as given above, though the *note using:: qualifier can
manipulate the order and provide values for missing columns.  For
example,

           plot 'file' with errorbars
           plot 'file' using 1:2:(sqrt($1)) with xerrorbars
           plot 'file' using 1:2:($1-$3):($1+$3):4:5 with xyerrorbars

   The last example is for a file containing an unsupported combination
of relative x and absolute y errors.  The *note using:: entry generates
absolute x min and max from the relative error.

   The y error bar is a vertical line plotted from (x, ylow) to (x,
yhigh). If ydelta is specified instead of ylow and yhigh, ylow = y -
ydelta and yhigh = y + ydelta are derived. If there are only two
numbers on the record, yhigh and ylow are both set to y. The x error
bar is a horizontal line computed in the same fashion. To get lines
plotted between the data points, `plot` the data file twice, once with
errorbars and once with lines (but remember to use the `notitle` option
on one to avoid two entries in the key). Alternately, use the
errorlines command (see *note errorlines::).

   The error bars have crossbars at each end unless *note bars:: is used
(see *note bars:: for details).

   If autoscaling is on, the ranges will be adjusted to include the
error bars.

   See also errorbar demos. (http://www.gnuplot.info/demo/mgr.html)

   See *note using::, *note with::, and *note style:: for more
information.


File: gnuplot.info,  Node: errorlines,  Next: functions,  Prev: errorbars,  Up: plot

3.15.5 errorlines
-----------------

Lines with error bars are supported for 2D data file plots by reading
one to four additional columns (or *note using:: entries); these
additional values are used in different ways by the various errorlines
styles.

   In the default situation, `gnuplot` expects to see three, four, or
six numbers on each line of the data file--either

           (x, y, ydelta),
           (x, y, ylow, yhigh),
           (x, y, xdelta),
           (x, y, xlow, xhigh),
           (x, y, xdelta, ydelta), or
           (x, y, xlow, xhigh, ylow, yhigh).

   The x coordinate must be specified. The order of the numbers must be
exactly as given above, though the *note using:: qualifier can
manipulate the order and provide values for missing columns. For
example,

           plot 'file' with errorlines
           plot 'file' using 1:2:(sqrt($1)) with xerrorlines
           plot 'file' using 1:2:($1-$3):($1+$3):4:5 with xyerrorlines

   The last example is for a file containing an unsupported combination
of relative x and absolute y errors. The *note using:: entry generates
absolute x min and max from the relative error.

   The y error bar is a vertical line plotted from (x, ylow) to (x,
yhigh). If ydelta is specified instead of ylow and yhigh, ylow = y -
ydelta and yhigh = y + ydelta are derived. If there are only two
numbers on the record, yhigh and ylow are both set to y. The x error
bar is a horizontal line computed in the same fashion.

   The error bars have crossbars at each end unless *note bars:: is used
(see *note bars:: for details).

   If autoscaling is on, the ranges will be adjusted to include the
error bars.

   See *note using::, *note with::, and *note style:: for more
information.


File: gnuplot.info,  Node: functions,  Next: parametric,  Prev: errorlines,  Up: plot

3.15.6 functions
----------------

Built-in or user-defined functions can be displayed by the `plot` and
`splot` commands in addition to, or instead of, data read from a file.
The requested function is evaluated by sampling at regular intervals
spanning the independent axis range[s]. See *note samples:: and *note
isosamples::.  Example:
           approx(ang) = ang - ang**3 / (3*2)
           plot sin(x) title "sin(x)", approx(x) title "approximation"

   To set a default plot style for functions, see `set style function`.
For information on built-in functions, see *note functions::.  For
information on defining your own functions, see `user-defined`.


File: gnuplot.info,  Node: parametric,  Next: ranges,  Prev: functions,  Up: plot

3.15.7 parametric
-----------------

When in parametric mode (`set parametric`) mathematical expressions
must be given in pairs for `plot` and in triplets for `splot`.

   Examples:
           plot sin(t),t**2
           splot cos(u)*cos(v),cos(u)*sin(v),sin(u)

   Data files are plotted as before, except any preceding parametric
function must be fully specified before a data file is given as a plot.
In other words, the x parametric function (`sin(t)` above) and the y
parametric function (`t**2` above) must not be interrupted with any
modifiers or data functions; doing so will generate a syntax error
stating that the parametric function is not fully specified.

   Other modifiers, such as *note with:: and *note title::, may be
specified only after the parametric function has been completed:

           plot sin(t),t**2 title 'Parametric example' with linespoints

   See also Parametric Mode Demos.
(http://www.gnuplot.info/demo/param.html)


File: gnuplot.info,  Node: ranges,  Next: iteration_,  Prev: parametric,  Up: plot

3.15.8 ranges
-------------

The optional ranges specify the region of the graph that will be
displayed.  Note that if you specify the range as part of a plot
command rather than using a separate `set range` statement, you will
not be able to pan or zoom the plot interactively, and will not be able
to change the range later and then *note replot::.

   Syntax:
           [{<dummy-var>=}{{<min>}:{<max>}}]
           [{{<min>}:{<max>}}]

   The first form applies to the independent variable (*note xrange::
or *note trange::, if in parametric mode).  The second form applies to
the dependent variable *note yrange:: (and *note xrange::, too, if in
parametric mode).  <dummy-var> is a new name for the independent
variable.  (The defaults may be changed with *note dummy::.)  The
optional <min> and <max> terms can be constant expressions or *.

   In non-parametric mode, the order in which ranges must be given is
*note xrange:: and *note yrange::.

   In parametric mode, the order for the `plot` command is *note
trange::, *note xrange::, and *note yrange::.  The following `plot`
command shows setting the *note trange:: to [-pi:pi], the *note
xrange:: to [-1.3:1.3] and the *note yrange:: to [-1:1] for the
duration of the graph:

           plot [-pi:pi] [-1.3:1.3] [-1:1] sin(t),t**2

   Note that the x2range and y2range cannot be specified here--*note
x2range:: and *note y2range:: must be used.

   Ranges are interpreted in the order listed above for the appropriate
mode.  Once all those needed are specified, no further ones must be
listed, but unneeded ones cannot be skipped--use an empty range `[]` as
a placeholder.

   `*` can be used to allow autoscaling of either of min and max.  See
also *note autoscale::.

   Ranges specified on the `plot` or `splot` command line affect only
that graph; use the *note xrange::, *note yrange::, etc., commands to
change the default ranges for future graphs.

   With time data, you must provide the range (in the same manner as
the time appears in the datafile) within quotes.  `gnuplot` uses the
*note timefmt:: string to read the value--see *note timefmt::.

   Examples:

   This uses the current ranges:
           plot cos(x)

   This sets the x range only:
           plot [-10:30] sin(pi*x)/(pi*x)

   This is the same, but uses t as the dummy-variable:
           plot [t = -10 :30]  sin(pi*t)/(pi*t)

   This sets both the x and y ranges:
           plot [-pi:pi] [-3:3]  tan(x), 1/x

   This sets only the y range, and turns off autoscaling on both axes:
           plot [ ] [-2:sin(5)*-8] sin(x)**besj0(x)

   This sets xmax and ymin only:
           plot [:200] [-pi:]  exp(sin(x))

   This sets the x range for a timeseries:
           set timefmt "%d/%m/%y %H:%M"
           plot ["1/6/93 12:00":"5/6/93 12:00"] 'timedata.dat'


File: gnuplot.info,  Node: iteration_,  Next: title,  Prev: ranges,  Up: plot

3.15.9 iteration
----------------

If many similar files or functions are to be plotted together, it may be
convenient to do so by iterating over a shared plot command.

   Syntax:
           plot for [<variable> = <start> : <end> {:<increment>}]
           plot for [<variable> in "string of words"]

   The scope of an iteration ends at the next comma or the end of the
command, whichever comes first.  Iteration can not be nested.

   This will plot one curve, sin(3x), because iteration ends at the
comma
           plot for [i=1:3] j=i, sin(j*x)

   This will plot three curves because there is no comma after the
definition of j
           plot for [i=1:3] j=i sin(j*x)

   Example:
           plot for [dataset in "apples bananas"] dataset."dat" title dataset

   In this example iteration is used both to generate a file name and a
corresponding title.

   Example:
           file(n) = sprintf("dataset_%d.dat",n)
           splot for [i=1:10] file(i) title sprintf("dataset %d",i)

   This example defines a string-valued function that generates file
names, and plots ten such files together. The iteration variable ('i'
in this example) is treated as an integer, and may be used more than
once.

   Example:
           set key left
           plot for [n=1:4] x**n sprintf("%d",n)

   This example plots a family of functions.

   Example:
           list = "apple banana cabbage daikon eggplant"
           item(n) = word(list,n)
           plot for [i=1:words(list)] item[i].".dat" title item(i)
           list = "new stuff"
           replot

   This example steps through a list and plots once per item.  Because
the items are retrieved dynamically, you can change the list and then
replot.

   Example:
           list = "apple banana cabbage daikon eggplant"
           plot for [i in list] i.".dat" title i
           list = "new stuff"
           replot

   This is example does exactly the same thing as the previous example,
but uses the string iterator form of the command rather than an integer
iterator.


File: gnuplot.info,  Node: title,  Next: with,  Prev: iteration_,  Up: plot

3.15.10 title
-------------

By default each plot is listed in the key by the corresponding function
or file name. You can give an explicit plot title instead using the
*note title:: option.

   Syntax:
           title <text> | notitle [<ignored text>]
           title columnheader | title columnheader(N)

   where <text> is a quoted string or an expression that evaluates to a
string.  The quotes will not be shown in the key.

   There is also an option that will interpret the first entry in a
column of input data (i.e. the column header) as a text field, and use
it as the key title.  See `datastrings`.  This can be made the default
by specifying *note columnhead::.

   The line title and sample can be omitted from the key by using the
keyword `notitle`.  A null title (`title "`) is equivalent to
`notitle`.  If only the sample is wanted, use one or more blanks
(`title ' '`).  If `notitle` is followed by a string this string is
ignored.

   If `key autotitles` is set (which is the default) and neither *note
title:: nor `notitle` are specified the line title is the function name
or the file name as it appears on the `plot` command.  If it is a file
name, any datafile modifiers specified will be included in the default
title.

   The layout of the key itself (position, title justification, etc.)
can be controlled by `set key`.  Please see `set key` for details.

   Examples:

   This plots y=x with the title 'x':
           plot x

   This plots x squared with title "x^2" and file "data.1" with title
"measured data":
           plot x**2 title "x^2", 'data.1' t "measured data"

   This puts an untitled circular border around a polar graph:
           set polar; plot my_function(t), 1 notitle

   Plot multiple columns of data, each of which contains its own title
in the file
           plot for [i=1:4] 'data' using i title columnhead


File: gnuplot.info,  Node: with,  Prev: title,  Up: plot

3.15.11 with
------------

Functions and data may be displayed in one of a large number of styles.
The *note with:: keyword provides the means of selection.

   Syntax:
           with <style> { {linestyle | ls <line_style>}
                          | {{linetype  | lt <line_type>}
                             {linewidth | lw <line_width>}
                             {linecolor | lc <colorspec>}
                             {pointtype | pt <point_type>}
                             {pointsize | ps <point_size>}
                             {fill | fs <fillstyle>}
                             {nohidden3d} {nocontours} {nosurface}
                             {palette}}
                        }

   where <style> is one of

          lines        dots       steps     errorbars     xerrorbar    xyerrorlines
          points       impulses   fsteps    errorlines    xerrorlines  yerrorbars
          linespoints  labels     histeps   financebars   xyerrorbars  yerrorlines
                                            vectors

   or
           boxes            candlesticks   image      circles
           boxerrorbars     filledcurves   rgbimage   ellipses
           boxxyerrorbars   histograms     rgbalpha   pm3d
           boxplot

   The first group of styles have associated line, point, and text
properties.  The second group of styles also have fill properties.  See
`fillstyle`.  Some styles have further sub-styles.  See `plotting
styles` for details of each.

   A default style may be chosen by `set style function` and `set style
data`.

   By default, each function and data file will use a different line
type and point type, up to the maximum number of available types.  All
terminal drivers support at least six different point types, and re-use
them, in order, if more are required.  To see the complete set of line
and point types available for the current terminal, type *note test::.

   If you wish to choose the line or point type for a single plot,
<line_type> and <point_type> may be specified.  These are positive
integer constants (or expressions) that specify the line type and point
type to be used for the plot.  Use *note test:: to display the types
available for your terminal.

   You may also scale the line width and point size for a plot by using
<line_width> and <point_size>, which are specified relative to the
default values for each terminal.  The pointsize may also be altered
globally--see *note pointsize:: for details.  But note that both
<point_size> as set here and  as set by *note pointsize:: multiply the
default point size--their effects are  not cumulative.  That is, `set
pointsize 2; plot x w p ps 3` will use points three times default size,
not six.

   It is also possible to specify `pointsize variable` either as part
of a line style or for an individual plot. In this case one extra
column of input is required, i.e. 3 columns for a 2D plot and 4 columns
for a 3D splot. The size of each individual point is determined by
multiplying the global pointsize by the value read from the data file.

   If you have defined specific line type/width and point type/size
combinations with `set style line`, one of these may be selected by
setting <line_style> to the index of the desired style.

   If gnuplot was built with *note pm3d:: support, the special keyword
*note palette:: is allowed for smooth color change of lines, points and
dots in `splots`. The color is chosen from a smooth palette which was
set previously with the command *note palette::. The color value
corresponds to the z-value of the point coordinates or to the color
coordinate if specified by the 4th parameter in *note using::. Both 2D
and 3D plots (`plot` and `splot` commands) can use palette colors as
specified by either their fractional value or the corresponding value
mapped to the colorbox range.  A palette color value can also be read
from an explicitly specified input column in the *note using::
specifier.  See `colors`, *note palette::, `linetype`.

   The keyword `nohidden3d` applies only to plots made with the `splot`
command.  Normally the global option *note hidden3d:: applies to all
plots in the graph.  You can attach the `nohidden3d` option to any
individual plots that you want to exclude from the hidden3d processing.
The individual elements other than surfaces (i.e. lines, dots, labels,
...) of a plot marked `nohidden3d` will all be drawn, even if they
would normally be obscured by other plot elements.

   Similarly, the keyword `nocontours` will turn off contouring for an
individual plot even if the global property *note contour:: is active.

   Similarly, the keyword `nosurface` will turn off the 3D surface for
an individual plot even if the global property *note surface:: is
active.

   The keywords may be abbreviated as indicated.

   Note that the `linewidth`, *note pointsize:: and *note palette::
options are not supported by all terminals.

   Examples:

   This plots sin(x) with impulses:
           plot sin(x) with impulses

   This plots x with points, x**2 with the default:
           plot x w points, x**2

   This plots tan(x) with the default function style, file "data.1"
with lines:
           plot [ ] [-2:5] tan(x), 'data.1' with l

   This plots "leastsq.dat" with impulses:
           plot 'leastsq.dat' w i

   This plots the data file "population" with boxes:
           plot 'population' with boxes

   This plots "exper.dat" with errorbars and lines connecting the points
(errorbars require three or four columns):
           plot 'exper.dat' w lines, 'exper.dat' notitle w errorbars

   Another way to plot "exper.dat" with errorlines (errorbars require
three or four columns):
           plot 'exper.dat' w errorlines

   This plots sin(x) and cos(x) with linespoints, using the same line
type but different point types:
           plot sin(x) with linesp lt 1 pt 3, cos(x) with linesp lt 1 pt 4

   This plots file "data" with points of type 3 and twice usual size:
           plot 'data' with points pointtype 3 pointsize 2

   This plots file "data" with variable pointsize read from column 4
           plot 'data' using 1:2:4 with points pt 5 pointsize variable

   This plots two data sets with lines differing only by weight:
           plot 'd1' t "good" w l lt 2 lw 3, 'd2' t "bad" w l lt 2 lw 1

   This plots filled curve of x*x and a color stripe:
           plot x*x with filledcurve closed, 40 with filledcurve y1=10

   This plots x*x and a color box:
           plot x*x, (x>=-5 && x<=5 ? 40 : 1/0) with filledcurve y1=10 lt 8

   This plots a surface with color lines:
           splot x*x-y*y with line palette

   This plots two color surfaces at different altitudes:
           splot x*x-y*y with pm3d, x*x+y*y with pm3d at t


File: gnuplot.info,  Node: print,  Next: pwd,  Prev: plot,  Up: Commands

3.16 print
==========

The *note print:: command prints the value of <expression> to the
screen.  It is synonymous with `pause 0`.  <expression> may be anything
that `gnuplot` can evaluate that produces a number, or it can be a
string.

   Syntax:
           print <expression> {, <expression>, ...}

   See `expressions`.  The output file can be set with *note print::.


File: gnuplot.info,  Node: pwd,  Next: quit,  Prev: print,  Up: Commands

3.17 pwd
========

The *note pwd:: command prints the name of the working directory to the
screen.

   Note that if you wish to store the current directory into a string
variable or use it in string expressions, then you can use variable
GPVAL_PWD, see `show variables all`.


File: gnuplot.info,  Node: quit,  Next: raise,  Prev: pwd,  Up: Commands

3.18 quit
=========

The *note exit:: and *note quit:: commands and END-OF-FILE character
will exit `gnuplot`.  Each of these commands will clear the output
device (as does the *note clear:: command) before exiting.


File: gnuplot.info,  Node: raise,  Next: refresh,  Prev: quit,  Up: Commands

3.19 raise
==========

Syntax:
           raise {plot_window_nb}

   The *note raise:: command raises (opposite to *note lower::) plot
window(s) associated with the interactive terminal of your gnuplot
session, i.e. `pm`, `win`, `wxt` or `x11`. It puts the plot window to
front (top) in the z-order windows stack of the window manager of your
desktop.

   As `x11` and `wxt` support multiple plot windows, then by default
they raise these windows in descending order of most recently created
on top to the least recently created on bottom. If a plot number is
supplied as an optional parameter, only the associated plot window will
be raised if it exists.

   The optional parameter is ignored for single plot-windows terminal,
i.e. `pm` and `win`.

   If the window is not raised under X11, then perhaps the plot window
is running in a different X11 session (telnet or ssh session, for
example), or perhaps raising is blocked by your window manager policy
setting.


File: gnuplot.info,  Node: refresh,  Next: replot,  Prev: raise,  Up: Commands

3.20 refresh
============

The *note refresh:: command is similar to *note replot::, with two
major differences.  *note refresh:: reformats and redraws the current
plot using the data already read in. This means that you can use *note
refresh:: for plots with in-line data (pseudo-device '-') and for plots
from datafiles whose contents are volatile.  You cannot use the *note
refresh:: command to add new data to an existing plot.

   Mousing operations, in particular zoom and unzoom, will use *note
refresh:: rather than *note replot:: if appropriate.  Example:

           plot 'datafile' volatile with lines, '-' with labels
           100 200 "Special point"
           e
           # Various mousing operations go here
           set title "Zoomed in view"
           set term post
           set output 'zoom.ps'
           refresh


File: gnuplot.info,  Node: replot,  Next: reread,  Prev: refresh,  Up: Commands

3.21 replot
===========

The *note replot:: command without arguments repeats the last `plot` or
`splot` command.  This can be useful for viewing a plot with different
`set` options, or when generating the same plot for several devices.

   Arguments specified after a *note replot:: command will be added
onto the last `plot` or `splot` command (with an implied ',' separator)
before it is repeated.  *note replot:: accepts the same arguments as
the `plot` and `splot` commands except that ranges cannot be specified.
Thus you can use *note replot:: to plot a function against the second
axes if the previous command was `plot` but not if it was `splot`.

   N.B.--use of

           plot '-' ; ... ; replot

   is not recommended, because it will require that you type in the
data all over again.  In most cases you can use the *note refresh::
command instead, which will redraw the plot using the data previously
read in.

   Note that *note replot:: does not work in *note multiplot:: mode,
since it reproduces only the last plot rather than the entire screen.

   See also `command-line-editing` for ways to edit the last `plot`
(`splot`) command.

   See also `show plot` to show the whole current plotting command, and
the possibility to copy it into the `history`.


File: gnuplot.info,  Node: reread,  Next: reset,  Prev: replot,  Up: Commands

3.22 reread
===========

The *note reread:: command causes the current `gnuplot` command file,
as specified by a `load` command or on the command line, to be reset to
its starting point before further commands are read from it.  This
essentially implements an endless loop of the commands from the
beginning of the command file to the *note reread:: command.  (But this
is not necessarily a disaster--*note reread:: can be very useful when
used in conjunction with `if`.)  The *note reread:: command has no
effect if input from standard input.

   Examples:

   Suppose the file "looper" contains the commands
           a=a+1
           plot sin(x*a)
           pause -1
           if(a<5) reread

   and from within `gnuplot` you submit the commands
           a=0
           load 'looper'

   The result will be five plots (separated by the *note pause::
message).

   Suppose the file "data" contains six columns of numbers with a total
yrange from 0 to 10; the first is x and the next are five different
functions of x.  Suppose also that the file "plotter" contains the
commands
           c_p = c_p+1
           plot "$0" using 1:c_p with lines linetype c_p
           if(c_p <  n_p) reread

   and from within `gnuplot` you submit the commands
           n_p=6
           c_p=1
           unset key
           set yrange [0:10]
           set multiplot
           call 'plotter' 'data'
           unset multiplot

   The result is a single graph consisting of five plots.  The yrange
must be set explicitly to guarantee that the five separate graphs
(drawn on top of each other in multiplot mode) will have exactly the
same axes.  The linetype must be specified; otherwise all the plots
would be drawn with the same type.  See animate.dem in demo directory
for an animated example.


File: gnuplot.info,  Node: reset,  Next: save,  Prev: reread,  Up: Commands

3.23 reset
==========

The *note reset:: command causes all graph-related options that can be
set with the `set` command to take on their default values.  This
command is useful, e.g., to restore the default graph settings at the
end of a command file, or to return to a defined state after lots of
settings have been changed within a command file.  Please refer to the
`set` command to see the default values that the various options take.

   The following are _not_ affected by *note reset::.
          `set term` *note output:: *note loadpath:: *note fontpath:: `set linetype`
          *note encoding:: *note decimalsign:: *note locale:: *note psdir::

   `reset errors` clears only the error state variables GPVAL_ERRNO and
GPVAL_ERRMSG.

   `reset bind` restores all hotkey bindings to their default state.


File: gnuplot.info,  Node: save,  Next: set-show,  Prev: reset,  Up: Commands

3.24 save
=========

The *note save:: command saves user-defined functions, variables, the
`set term` status, all `set` options, or all of these, plus the last
`plot` (`splot`) command to the specified file.

   Syntax:
           save  {<option>} '<filename>'

   where <option> is *note functions::, *note variables::, *note
terminal:: or `set`. If no option is used, `gnuplot` saves functions,
variables, `set` options and the last `plot` (`splot`) command.

   *note save::d files are written in text format and may be read by the
`load` command. For *note save:: with the `set` option or without any
option, the *note terminal:: choice and the *note output:: filename are
written out as a comment, to get an output file that works in other
installations of gnuplot, without changes and without risk of
unwillingly overwriting files.

   *note terminal:: will write out just the *note terminal:: status,
without the comment marker in front of it. This is mainly useful for
switching the *note terminal:: setting for a short while, and getting
back to the previously set terminal, afterwards, by loading the saved
*note terminal:: status. Note that for a single gnuplot session you may
rather use the other method of saving and restoring current terminal by
the commands `set term push` and `set term pop`, see `set term`.

   The filename must be enclosed in quotes.

   The special filename "-" may be used to *note save:: commands to
standard output.  On systems which support a popen function (Unix), the
output of save can be piped through an external program by starting the
file name with a '|'.  This provides a consistent interface to
`gnuplot`'s internal settings to programs which communicate with
`gnuplot` through a pipe.  Please see help for `batch/interactive` for
more details.

   Examples:
           save 'work.gnu'
           save functions 'func.dat'
           save var 'var.dat'
           save set 'options.dat'
           save term 'myterm.gnu'
           save '-'
           save '|grep title >t.gp'


File: gnuplot.info,  Node: set-show,  Next: shell,  Prev: save,  Up: Commands

3.25 set-show
=============

The `set` command can be used to set _lots_ of options.  No screen is
drawn, however, until a `plot`, `splot`, or *note replot:: command is
given.

   The `show` command shows their settings;  `show all` shows all the
settings.

   Options changed using `set` can be returned to the default state by
giving the corresponding *note unset:: command.  See also the *note
reset:: command, which returns all settable parameters to default
values.

   If a variable contains time/date data, `show` will display it
according to the format currently defined by *note timefmt::, even if
that was not in effect when the variable was initially defined.  

   The `set` and *note unset:: commands may optionally contain an
iteration clause.  See *note iteration::.

* Menu:

* angles::
* arrow::
* autoscale::
* bars::
* bind_::
* bmargin::
* border::
* boxwidth::
* clabel::
* clip::
* cntrparam::
* color_box::
* colornames::
* contour::
* data_style::
* datafile::
* decimalsign::
* dgrid3d::
* dummy::
* encoding::
* fit_::
* fontpath::
* format_::
* function_style::
* functions_::
* grid::
* hidden3d::
* historysize::
* isosamples::
* key::
* label::
* linetype::
* lmargin::
* loadpath::
* locale::
* logscale::
* macros::
* mapping::
* margin::
* mouse::
* multiplot::
* mx2tics::
* mxtics::
* my2tics::
* mytics::
* mztics::
* object::
* offsets::
* origin::
* output::
* parametric_::
* plot_::
* pm3d::
* palette::
* pointintervalbox::
* pointsize::
* polar_::
* print_::
* psdir::
* raxis::
* rmargin::
* rrange::
* rtics::
* samples::
* size::
* style::
* surface::
* table::
* terminal::
* termoption::
* tics::
* ticslevel::
* ticscale::
* timestamp::
* timefmt::
* title_::
* tmargin::
* trange::
* urange::
* variables::
* version::
* view::
* vrange::
* x2data::
* x2dtics::
* x2label::
* x2mtics::
* x2range::
* x2tics::
* x2zeroaxis::
* xdata::
* xdtics::
* xlabel::
* xmtics::
* xrange::
* xtics::
* xyplane::
* xzeroaxis::
* y2data::
* y2dtics::
* y2label::
* y2mtics::
* y2range::
* y2tics::
* y2zeroaxis::
* ydata::
* ydtics::
* ylabel::
* ymtics::
* yrange::
* ytics::
* yzeroaxis::
* zdata::
* zdtics::
* zzeroaxis::
* cbdata::
* cbdtics::
* zero::
* zeroaxis::
* zlabel::
* zmtics::
* zrange::
* ztics::
* cblabel::
* cbmtics::
* cbrange::
* cbtics::


File: gnuplot.info,  Node: angles,  Next: arrow,  Prev: set-show,  Up: set-show

3.25.1 angles
-------------

By default, `gnuplot` assumes the independent variable in polar graphs
is in units of radians.  If `set angles degrees` is specified before
`set polar`, then the default range is [0:360] and the independent
variable has units of degrees.  This is particularly useful for plots
of data files.  The angle setting also applies to 3D mapping as set via
the *note mapping:: command.

   Syntax:
           set angles {degrees | radians}
           show angles

   The angle specified in `set grid polar` is also read and displayed
in the units specified by *note angles::.

   *note angles:: also affects the arguments of the machine-defined
functions sin(x), cos(x) and tan(x), and the outputs of asin(x),
acos(x), atan(x), atan2(x), and arg(x).  It has no effect on the
arguments of hyperbolic functions or Bessel functions.  However, the
output arguments of inverse hyperbolic functions of complex arguments
are affected; if these functions are used, `set angles radians` must be
in effect to maintain consistency between input and output arguments.

           x={1.0,0.1}
           set angles radians
           y=sinh(x)
           print y         #prints {1.16933, 0.154051}
           print asinh(y)  #prints {1.0, 0.1}

   but
           set angles degrees
           y=sinh(x)
           print y         #prints {1.16933, 0.154051}
           print asinh(y)  #prints {57.29578, 5.729578}

   See also poldat.dem: polar plot using *note angles:: demo.
(http://www.gnuplot.info/demo/poldat.html)


File: gnuplot.info,  Node: arrow,  Next: autoscale,  Prev: angles,  Up: set-show

3.25.2 arrow
------------

Arbitrary arrows can be placed on a plot using the *note arrow::
command.

   Syntax:
           set arrow {<tag>} {from <position>} {to|rto <position>}
                     { {arrowstyle | as <arrow_style>}
                       | { {nohead | head | backhead | heads}
                           {size <length>,<angle>{,<backangle>}}
                           {filled | empty | nofilled}
                           {front | back}
                           { {linestyle | ls <line_style>}
                             | {linetype | lt <line_type>}
                               {linewidth | lw <line_width} } } }

           unset arrow {<tag>}
           show arrow {<tag>}

   <tag> is an integer that identifies the arrow.  If no tag is given,
the lowest unused tag value is assigned automatically.  The tag can be
used to delete or change a specific arrow.  To change any attribute of
an existing arrow, use the *note arrow:: command with the appropriate
tag and specify the parts of the arrow to be changed.

   The <position>s are specified by either x,y or x,y,z, and may be
preceded by `first`, `second`, `graph`, `screen`, or `character` to
select the coordinate system.  Unspecified coordinates default to 0.
The end points can be specified in one of five coordinate
systems--`first` or `second` axes, `graph`, `screen`, or `character`.
See `coordinates` for details.  A coordinate system specifier does not
carry over from the "from" position to the "to" position.  Arrows
outside the screen boundaries are permitted but may cause device
errors.  If the end point is specified by "rto" instead of "to" it is
drawn relatively to the start point.  For linear axes, `graph` and
`screen` coordinates, the distance between the start and the end point
corresponds to the given relative coordinate.  For logarithmic axes, the
relative given coordinate corresponds to the factor of the coordinate
between start and end point.  Thus, a negative relative value or zero
are not allowed for logarithmic axes.

   Specifying `nohead` produces an arrow drawn without a head--a line
segment.  This gives you yet another way to draw a line segment on the
plot.  By default, an arrow has a head at its end. Specifying
`backhead` draws an arrow head at the start point of the arrow while
`heads` draws arrow heads on both ends of the line.  Not all terminal
types support double-ended arrows.

   Head size can be controlled by `size <length>,<angle>` or `size
<length>,<angle>,<backangle>`, where `<length>` defines length of each
branch of the arrow head and `<angle>` the angle (in degrees) they make
with the arrow.  `<Length>` is in x-axis units; this can be changed by
`first`, `second`, `graph`, `screen`, or `character` before the
<length>;  see `coordinates` for details.  `<Backangle>` only takes
effect when `filled` or `empty` is also used.  Then, `<backangle>` is
the angle (in degrees) the back branches make with the arrow (in the
same direction as `<angle>`).  The `fig` terminal has a restricted
backangle function. It supports three different angles. There are two
thresholds: Below 70 degrees, the arrow head gets an indented back
angle. Above 110 degrees, the arrow head has an acute back angle.
Between these thresholds, the back line is straight.

   Specifying `filled` produces filled arrow heads (if heads are used).
Filling is supported on filled-polygon capable terminals, see help of
*note pm3d:: for their list, otherwise the arrow heads are closed but
not filled.  The same result (closed but not filled arrow head) is
reached by specifying `empty`.  Further, filling and outline is
obviously not supported on terminals drawing arrows by their own
specific routines, like `metafont`, `metapost`, `latex` or `tgif`.

   The line style may be selected from a user-defined list of line
styles (see `set style line`) or may be defined here by providing
values for <line_type> (an index from the default list of styles)
and/or <line_width> (which is a  multiplier for the default width).

   Note, however, that if a user-defined line style has been selected,
its properties (type and width) cannot be altered merely by issuing
another *note arrow:: command with the appropriate index and `lt` or
`lw`.

   If `front` is given, the arrow is written on top of the graphed
data. If `back` is given (the default), the arrow is written underneath
the graphed data.  Using `front` will prevent an arrow from being
obscured by dense data.

   Examples:

   To set an arrow pointing from the origin to (1,2) with user-defined
style 5, use:
           set arrow to 1,2 ls 5

   To set an arrow from bottom left of plotting area to (-5,5,3), and
tag the arrow number 3, use:
           set arrow 3 from graph 0,0 to -5,5,3

   To change the preceding arrow to end at 1,1,1, without an arrow head
and double its width, use:
           set arrow 3 to 1,1,1 nohead lw 2

   To draw a vertical line from the bottom to the top of the graph at
x=3, use:
           set arrow from 3, graph 0 to 3, graph 1 nohead

   To draw a vertical arrow with T-shape ends, use:
           set arrow 3 from 0,-5 to 0,5 heads size screen 0.1,90

   To draw an arrow relatively to the start point, where the relative
distances are given in graph coordinates, use:
           set arrow from 0,-5 rto graph 0.1,0.1

   To draw an arrow with relative end point in logarithmic x axis, use:
           set logscale x
           set arrow from 100,-5 rto 10,10

   This draws an arrow from 100,-5 to 1000,5. For the logarithmic x
axis, the relative coordinate 10 means "factor 10" while for the linear
y axis, the relative coordinate 10 means "difference 10".

   To delete arrow number 2, use:
           unset arrow 2

   To delete all arrows, use:
           unset arrow

   To show all arrows (in tag order), use:
           show arrow

   arrows demos. (http://www.gnuplot.info/demo/arrowstyle.html)


File: gnuplot.info,  Node: autoscale,  Next: bars,  Prev: arrow,  Up: set-show

3.25.3 autoscale
----------------

Autoscaling may be set individually on the x, y or z axis or globally
on all axes. The default is to autoscale all axes.  If you want to
autoscale based on a subset of the plots in the figure, you can mark
the other ones with the flag `noautoscale`.  See *note datafile::.

   Syntax:
           set autoscale {<axes>{|min|max|fixmin|fixmax|fix} | fix | keepfix}
           unset autoscale {<axes>}
           show autoscale

   where <axes> is either `x`, `y`, `z`, `cb`, `x2`, `y2` or `xy`.  A
keyword with `min` or `max` appended (this cannot be done with `xy`)
tells `gnuplot` to autoscale just the minimum or maximum of that axis.
If no keyword is given, all axes are autoscaled.

   A keyword with `fixmin`, `fixmax` or `fix` appended tells gnuplot to
disable extension of the axis range to the next tic mark position, for
autoscaled axes using equidistant tics; `set autoscale fix` sets this
for all axes.  Command `set autoscale keepfix` autoscales all axes
while keeping the fix settings.

   When autoscaling, the axis range is automatically computed and the
dependent axis (y for a `plot` and z for `splot`) is scaled to include
the range of the function or data being plotted.

   If autoscaling of the dependent axis (y or z) is not set, the
current y or z range is used.

   Autoscaling the independent variables (x for `plot` and x,y for
`splot`) is a request to set the domain to match any data file being
plotted.  If there are no data files, autoscaling an independent
variable has no effect.  In other words, in the absence of a data file,
functions alone do not affect the x range (or the y range if plotting z
= f(x,y)).

   Please see *note xrange:: for additional information about ranges.

   The behavior of autoscaling remains consistent in parametric mode,
(see `set parametric`).  However, there are more dependent variables
and hence more control over x, y, and z axis scales.  In parametric
mode, the independent or dummy variable is t for `plot`s and u,v for
`splot`s.  *note autoscale:: in parametric mode, then, controls all
ranges (t, u, v, x, y, and z) and allows x, y, and z to be fully
autoscaled.

   Autoscaling works the same way for polar mode as it does for
parametric mode for `plot`, with the extension that in polar mode *note
dummy:: can be used to change the independent variable from t (see
*note dummy::).

   When tics are displayed on second axes but no plot has been
specified for those axes, x2range and y2range are inherited from xrange
and yrange.  This is done _before_ xrange and yrange are autoextended
to a whole number of tics, which can cause unexpected results.  You can
use the `fixmin` or `fixmax` options to avoid this.

   Examples:

   This sets autoscaling of the y axis (other axes are not affected):
           set autoscale y

   This sets autoscaling only for the minimum of the y axis (the
maximum of the y axis and the other axes are not affected):
           set autoscale ymin

   This disables extension of the x2 axis tics to the next tic mark,
thus keeping the exact range as found in the plotted data and functions:
           set autoscale x2fixmin
           set autoscale x2fixmax

   This sets autoscaling of the x and y axes:
           set autoscale xy

   This sets autoscaling of the x, y, z, x2 and y2 axes:
           set autoscale

   This disables autoscaling of the x, y, z, x2 and y2 axes:
           unset autoscale

   This disables autoscaling of the z axis only:
           unset autoscale z

* Menu:

* parametric_mode::
* polar_mode::


File: gnuplot.info,  Node: parametric_mode,  Next: polar_mode,  Prev: autoscale,  Up: autoscale

3.25.3.1 parametric mode
........................

When in parametric mode (`set parametric`), the xrange is as fully
scalable as the y range.  In other words, in parametric mode the x axis
can be automatically scaled to fit the range of the parametric function
that is being plotted.  Of course, the y axis can also be automatically
scaled just as in the non-parametric case.  If autoscaling on the x
axis is not set, the current x range is used.

   Data files are plotted the same in parametric and non-parametric
mode.  However, there is a difference in mixed function and data plots:
in non-parametric mode with autoscaled x, the x range of the datafile
controls the x range of the functions; in parametric mode it has no
influence.

   For completeness a last command `set autoscale t` is accepted.
However, the effect of this "scaling" is very minor.  When `gnuplot`
determines that the t range would be empty, it makes a small adjustment
if autoscaling is true.  Otherwise, `gnuplot` gives an error.  Such
behavior may, in fact, not be very useful and the command `set
autoscale t` is certainly questionable.

   `splot` extends the above ideas as you would expect.  If autoscaling
is set, then x, y, and z ranges are computed and each axis scaled to
fit the resulting data.


File: gnuplot.info,  Node: polar_mode,  Prev: parametric_mode,  Up: autoscale

3.25.3.2 polar mode
...................

When in polar mode (`set polar`), the xrange and the yrange may be left
in autoscale mode.  If *note rrange:: is used to limit the extent of
the polar axis, then xrange and yrange will adjust to match this
automatically.  However, explicit xrange and yrange commands can later
be used to make further adjustments.  See *note rrange::.  The trange
may also be autoscaled.  Note that if the trange is contained within
one quadrant, autoscaling will produce a polar plot of only that single
quadrant.

   Explicitly setting one or two ranges but not others may lead to
unexpected results.  See also polar demos.
(http://www.gnuplot.info/demo/poldat.html)


File: gnuplot.info,  Node: bars,  Next: bind_,  Prev: autoscale,  Up: set-show

3.25.4 bars
-----------

The *note bars:: command controls the tics at the ends of error bars,
and also at the end of the whiskers belonging to a boxplot.

   Syntax:
           set bars {small | large | fullwidth | <size>} {front | back}
           unset bars
           show bars

   `small` is a synonym for 0.0, and `large` for 1.0.  The default is
1.0 if no size is given.

   The keyword `fullwidth` is relevant only to boxplots and to
histograms with errorbars.  It sets the width of the errorbar ends to
be the same as the width of the associated box.  It does not change the
width of the box itself.

   The `front` and `back` keywords are relevant only to errorbars
attached to filled rectangles (boxes, candlesticks, histograms).


File: gnuplot.info,  Node: bind_,  Next: bmargin,  Prev: bars,  Up: set-show

3.25.5 bind
-----------

Show the current state of all hotkey bindings. See `bind`.


File: gnuplot.info,  Node: bmargin,  Next: border,  Prev: bind_,  Up: set-show

3.25.6 bmargin
--------------

The command *note bmargin:: sets the size of the bottom margin.  Please
see *note margin:: for details.


File: gnuplot.info,  Node: border,  Next: boxwidth,  Prev: bmargin,  Up: set-show

3.25.7 border
-------------

The *note border:: and *note border:: commands control the display of
the graph borders for the `plot` and `splot` commands.  Note that the
borders do not necessarily coincide with the axes; with `plot` they
often do, but with `splot` they usually do not.

   Syntax:
           set border {<integer>} {front | back} {linewidth | lw <line_width>}
                      {{linestyle | ls <line_style>} | {linetype | lt <line_type>}}
           unset border
           show border

   With a `splot` displayed in an arbitrary orientation, like `set view
56,103`, the four corners of the x-y plane can be referred to as
"front", "back", "left" and "right".  A similar set of four corners
exist for the top surface, of course.  Thus the border connecting, say,
the back and right corners of the x-y plane is the "bottom right back"
border, and the border connecting the top and bottom front corners is
the "front vertical".  (This nomenclature is defined solely to allow
the reader to figure out the table that follows.)

   The borders are encoded in a 12-bit integer: the bottom four bits
control the border for `plot` and the sides of the base for `splot`;
the next four bits control the verticals in `splot`; the top four bits
control the edges on top of the `splot`.  In detail, `<integer>` should
be the sum of the appropriate entries from the following table:

                 Bit     plot        splot
                   1   bottom      bottom left front
                   2   left        bottom left back
                   4   top         bottom right front
                   8   right       bottom right back
                  16   no effect   left vertical
                  32   no effect   back vertical
                  64   no effect   right vertical
                 128   no effect   front vertical
                 256   no effect   top left back
                 512   no effect   top right back
                1024   no effect   top left front
                2048   no effect   top right front

   Various bits or combinations of bits may be added together in the
command.

   The default is 31, which is all four sides for `plot`, and base and
z axis for `splot`.

   In 2D plots the border is normally drawn on top of all plots elements
(`front`). If you want the border to be drawn behind the plot elements,
use `set border back`.

   Using the optional <line_style>, <line_type> and <line_width>
specifiers, the way the border lines are drawn can be influenced
(limited by what the current terminal driver supports).

   For `plot`, tics may be drawn on edges other than bottom and left by
enabling the second axes - see `set xtics` for details.

   If a `splot` draws only on the base, as is the case with "`unset
surface; set contour base`", then the verticals and the top are not
drawn even if they are specified.

   The `set grid` options 'back', 'front' and 'layerdefault' also
control the order in which the border lines are drawn with respect to
the output of the plotted data.

   Examples:

   Draw default borders:
           set border

   Draw only the left and bottom (`plot`) or both front and back bottom
left (`splot`) borders:
           set border 3

   Draw a complete box around a `splot`:
           set border 4095

   Draw a topless box around a `splot`, omitting the front vertical:
           set border 127+256+512 # or set border 1023-128

   Draw only the top and right borders for a `plot` and label them as
axes:
           unset xtics; unset ytics; set x2tics; set y2tics; set border 12


File: gnuplot.info,  Node: boxwidth,  Next: clabel,  Prev: border,  Up: set-show

3.25.8 boxwidth
---------------

The *note boxwidth:: command is used to set the default width of boxes
in the *note boxes::, *note boxerrorbars::, *note boxplot::, *note
candlesticks:: and *note histograms:: styles.

   Syntax:
           set boxwidth {<width>} {absolute|relative}
           show boxwidth

   By default, adjacent boxes are extended in width until they touch
each other.  A different default width may be specified using the *note
boxwidth:: command.  `Relative` widths are interpreted as being a
fraction of this default width.

   An explicit value for the boxwidth is interpreted as being a number
of units along the current x axis (`absolute`) unless the modifier
`relative` is given.  If the x axis is a log-scale (see `set log`) then
the value of boxwidth is truly "absolute" only at x=1; this physical
width is maintained everywhere along the axis (i.e. the boxes do not
become narrower the value of x increases). If the range spanned by a
log scale x axis is far from x=1, some experimentation may be required
to find a useful value of boxwidth.

   The default is superseded by explicit width information taken from
an extra data column in styles *note boxes:: or *note boxerrorbars::.
In a four-column data set, the fourth column will be interpreted as the
box width unless the width is set to -2.0, in which case the width will
be calculated automatically.  See *note boxes:: and *note
boxerrorbars:: for more details.

   To set the box width to automatic use the command
           set boxwidth

   or, for four-column data,
           set boxwidth -2

   The same effect can be achieved with the *note using:: keyword in
`plot`:
           plot 'file' using 1:2:3:4:(-2)

   To set the box width to half of the automatic size use
           set boxwidth 0.5 relative

   To set the box width to an absolute value of 2 use
           set boxwidth 2 absolute


File: gnuplot.info,  Node: clabel,  Next: clip,  Prev: boxwidth,  Up: set-show

3.25.9 clabel
-------------

`gnuplot` will vary the linetype used for each contour level when
clabel is set.  When this option on (the default), a legend labels each
linestyle with the z level it represents.  It is not possible at
present to separate the contour labels from the surface key.

   Syntax:
           set clabel {'<format>'}
           unset clabel
           show clabel

   The default for the format string is %8.3g, which gives three
decimal places.  This may produce poor label alignment if the key is
altered from its default configuration.

   The first contour linetype, or only contour linetype when clabel is
off, is the surface linetype +1; contour points are the same style as
surface points.

   See also *note contour::.


File: gnuplot.info,  Node: clip,  Next: cntrparam,  Prev: clabel,  Up: set-show

3.25.10 clip
------------

`gnuplot` can clip data points and lines that are near the boundaries
of a graph.

   Syntax:
           set clip <clip-type>
           unset clip <clip-type>
           show clip

   Three clip types for points and lines are supported by `gnuplot`:
`points`, `one`, and `two`. One, two, or all three clip types may be
active for a single graph.  Note that clipping of color filled
quadrangles drawn by *note pm3d:: maps and surfaces is not controlled
by this command, but by `set pm3d clip1in` and `set pm3d clip4in`.

   The `points` clip type forces `gnuplot` to clip (actually, not plot
at all) data points that fall within but too close to the boundaries.
This is done so that large symbols used for points will not extend
outside the boundary lines.  Without clipping points near the
boundaries, the plot may look bad.  Adjusting the x and y ranges may
give similar results.

   Setting the `one` clip type causes `gnuplot` to draw a line segment
which has only one of its two endpoints within the graph.  Only the
in-range portion of the line is drawn.  The alternative is to not draw
any portion of the line segment.

   Some lines may have both endpoints out of range, but pass through
the graph.  Setting the `two` clip-type allows the visible portion of
these lines to be drawn.

   In no case is a line drawn outside the graph.

   The defaults are `noclip points`, `clip one`, and `noclip two`.

   To check the state of all forms of clipping, use
           show clip

   For backward compatibility with older versions, the following forms
are also permitted:
           set clip
           unset clip

   `set clip` is synonymous with `set clip points`; `unset clip` turns
off all three types of clipping.


File: gnuplot.info,  Node: cntrparam,  Next: color_box,  Prev: clip,  Up: set-show

3.25.11 cntrparam
-----------------

*note cntrparam:: controls the generation of contours and their
smoothness for a contour plot. *note contour:: displays current
settings of *note cntrparam:: as well as *note contour::.

   Syntax:
           set cntrparam { { linear
                           | cubicspline
                           | bspline
                           | points <n>
                           | order <n>
                           | levels { auto {<n>} | <n>
                                      | discrete <z1> {,<z2>{,<z3>...}}
                                      | incremental <start>, <incr> {,<end>}
                                    }
                           }
                         }
           show contour

   This command has two functions.  First, it sets the values of z for
which contour points are to be determined (by linear interpolation
between data points or function isosamples.)  Second, it controls the
way contours are drawn between the points determined to be of equal z.
<n> should be an integral constant expression and <z1>, <z2> ... any
constant expressions.  The parameters are:

   `linear`, `cubicspline`, `bspline`--Controls type of approximation or
interpolation.  If `linear`, then straight line segments connect points
of equal z magnitude.  If `cubicspline`, then piecewise-linear contours
are interpolated between the same equal z points to form somewhat
smoother contours, but which may undulate.  If `bspline`, a
guaranteed-smoother curve is drawn, which only approximates the
position of the points of equal-z.

   `points`--Eventually all drawings are done with piecewise-linear
strokes.  This number controls the number of line segments used to
approximate the `bspline` or `cubicspline` curve.  Number of
cubicspline or bspline segments (strokes) = `points` * number of linear
segments.

   `order`--Order of the bspline approximation to be used.  The bigger
this order is, the smoother the resulting contour.  (Of course, higher
order bspline curves will move further away from the original piecewise
linear data.)  This option is relevant for `bspline` mode only.
Allowed values are integers in the range from 2 (linear) to 10.

   `levels`-- Selection of contour levels,  controlled by `auto`
(default), `discrete`, `incremental`, and <n>, number of contour levels.

   For `auto`, <n> specifies a nominal number of levels; the actual
number will be adjusted to give simple labels. If the surface is
bounded by zmin and zmax, contours will be generated at integer
multiples of dz between zmin and zmax, where dz is 1, 2, or 5 times
some power of ten (like the step between two tic marks).

   For `levels discrete`, contours will be generated at z = <z1>, <z2>
... as specified; the number of discrete levels sets the number of
contour levels.  In `discrete` mode, any `set cntrparam levels <n>` are
ignored.

   For `incremental`, contours are generated at values of z beginning
at <start> and increasing by <increment>, until the number of contours
is reached. <end> is used to determine the number of contour levels,
which will be changed by any subsequent `set cntrparam levels <n>`.  If
the z axis is logarithmic, <increment> will be interpreted as a factor,
just like in *note ztics::.

   If the command *note cntrparam:: is given without any arguments
specified,  the defaults are used: linear, 5 points, order 4, 5 auto
levels.

   Examples:
           set cntrparam bspline
           set cntrparam points 7
           set cntrparam order 10

   To select levels automatically, 5 if the level increment criteria
are met:
           set cntrparam levels auto 5

   To specify discrete levels at .1, .37, and .9:
           set cntrparam levels discrete .1,1/exp(1),.9

   To specify levels from 0 to 4 with increment 1:
           set cntrparam levels incremental  0,1,4

   To set the number of levels to 10 (changing an incremental end or
possibly the number of auto levels):
           set cntrparam levels 10

   To set the start and increment while retaining the number of levels:
           set cntrparam levels incremental 100,50

   See also *note contour:: for control of where the contours are
drawn, and *note clabel:: for control of the format of the contour
labels and linetypes.

   See also contours demo (contours.dem)
(http://www.gnuplot.info/demo/contours.html) and contours with user
defined levels demo (discrete.dem).
(http://www.gnuplot.info/demo/discrete.html)


File: gnuplot.info,  Node: color_box,  Next: colornames,  Prev: cntrparam,  Up: set-show

3.25.12 color box
-----------------

The color scheme, i.e. the gradient of the smooth color with min_z and
max_z values of *note pm3d::'s *note palette::, is drawn in a color box
unless `unset colorbox`.

           set colorbox
           set colorbox {
                      { vertical | horizontal }
                      { default | user }
                      { origin x, y }
                      { size x, y }
                      { front | back }
                      { noborder | bdefault | border [line style] }
                    }
           show colorbox
           unset colorbox

   Color box position can be `default` or `user`.  If the latter is
specified the values as given with the *note origin:: and *note size::
subcommands are used. The box can be drawn after (`front`) or before
(`back`) the graph or the surface.

   The orientation of the color gradient can be switched by options
`vertical` and `horizontal`.

   `origin x, y` and `size x, y` are used only in combination with the
`user` option. The x and y values are interpreted as screen coordinates
by default, and this is the only legal option for 3D plots. 2D plots,
including splot with `set view map`, allow any coordinate system to be
specified.  Try for example:
         set colorbox horiz user origin .1,.02 size .8,.04

   which will draw a horizontal gradient somewhere at the bottom of the
graph.

   *note border:: turns the border on (this is the default). `noborder`
turns the border off. If an positive integer argument is given after
*note border::, it is used as a line style tag which is used for
drawing the border, e.g.:
         set style line 2604 linetype -1 linewidth .4
         set colorbox border 2604

   will use line style `2604`, a thin line with the default border
color (-1) for drawing the border. `bdefault` (which is the default)
will use the default border line style for drawing the border of the
color box.

   The axis of the color box is called `cb` and it is controlled by
means of the usual axes commands, i.e. `set/unset/show` with *note
cbrange::, `[m]cbtics`, `format cb`, `grid [m]cb`, *note cblabel::, and
perhaps even *note cbdata::, `[no]cbdtics`, `[no]cbmtics`.

   `set colorbox` without any parameter switches the position to
default.  `unset colorbox` resets the default parameters for the
colorbox and switches the colorbox off.

   See also help for *note pm3d::, *note palette::, *note pm3d::, and
`set style line`.


File: gnuplot.info,  Node: colornames,  Next: contour,  Prev: color_box,  Up: set-show

3.25.13 colornames
------------------

Gnuplot knows a limited number of color names. You can use these to
define the color range spanned by a pm3d palette, or to assign a
terminal-independent color to a particular linetype or linestyle. To
see the list of known color names, use the command *note colornames::.
Example:

           set style line 1 linecolor rgb "sea-green"


File: gnuplot.info,  Node: contour,  Next: data_style,  Prev: colornames,  Up: set-show

3.25.14 contour
---------------

*note contour:: enables contour drawing for surfaces.  This option is
available for `splot` only.  It requires grid data, see `grid_data` for
more details.  If contours are desired from non-grid data, *note
dgrid3d:: can be used to create an appropriate grid.

   Syntax:
           set contour {base | surface | both}
           unset contour
           show contour

   The three options specify where to draw the contours: `base` draws
the contours on the grid base where the x/ytics are placed, *note
surface:: draws the contours on the surfaces themselves, and `both`
draws the contours on both the base and the surface.  If no option is
provided, the default is `base`.

   See also *note cntrparam:: for the parameters that affect the
drawing of contours, and *note clabel:: for control of labelling of the
contours.

   The surface can be switched off (see *note surface::), giving a
contour-only graph.  Though it is possible to use *note size:: to
enlarge the plot to fill the screen, more control over the output
format can be obtained by writing the contour information to a file,
and rereading it as a 2D datafile plot:

           unset surface
           set contour
           set cntrparam ...
           set table 'filename'
           splot ...
           unset table
           # contour info now in filename
           set term <whatever>
           plot 'filename'

   In order to draw contours, the data should be organized as "grid
data".  In such a file all the points for a single y-isoline are
listed, then all the points for the next y-isoline, and so on.  A
single blank line (a line containing no characters other than blank
spaces and a carriage return and/or a line feed) separates one
y-isoline from the next.  See also *note datafile::.

   See also contours demo (contours.dem)
(http://www.gnuplot.info/demo/contours.html) and contours with user
defined levels demo (discrete.dem).
(http://www.gnuplot.info/demo/discrete.html)


File: gnuplot.info,  Node: data_style,  Next: datafile,  Prev: contour,  Up: set-show

3.25.15 data style
------------------

This form of the command is deprecated. Please see `set style data`.


File: gnuplot.info,  Node: datafile,  Next: decimalsign,  Prev: data_style,  Up: set-show

3.25.16 datafile
----------------

The *note datafile:: command options control interpretation of fields
read from input data files by the `plot`, `splot`, and *note fit::
commands.  Six such options are currently implemented.

* Menu:

* set_datafile_fortran::
* set_datafile_nofpe_trap::
* set_datafile_missing::
* set_datafile_separator::
* set_datafile_commentschars::
* set_datafile_binary::


File: gnuplot.info,  Node: set_datafile_fortran,  Next: set_datafile_nofpe_trap,  Prev: datafile,  Up: datafile

3.25.16.1 set datafile fortran
..............................

The `set datafile fortran` command enables a special check for values
in the input file expressed as Fortran D or Q constants. This extra
check slows down the input process, and should only be selected if you
do in fact have datafiles containing Fortran D or Q constants. The
option can be disabled again using `unset datafile fortran`.


File: gnuplot.info,  Node: set_datafile_nofpe_trap,  Next: set_datafile_missing,  Prev: set_datafile_fortran,  Up: datafile

3.25.16.2 set datafile nofpe_trap
.................................

The `set datafile nofpe_trap` command tells gnuplot not to
re-initialize a floating point exception handler before every
expression evaluation used while reading data from an input file.  This
can significantly speed data input from very large files at the risk of
program termination if a floating-point exception is generated.


File: gnuplot.info,  Node: set_datafile_missing,  Next: set_datafile_separator,  Prev: set_datafile_nofpe_trap,  Up: datafile

3.25.16.3 set datafile missing
..............................

The `set datafile missing` command allows you to tell `gnuplot` what
character string is used in a data file to denote missing data.
Exactly how this missing value will be treated depends on the *note
using:: specifier of the `plot` or `splot` command.

   Syntax:
           set datafile missing {"<string>"}
           show datafile missing
           unset datafile

   Example:
           # Ignore entries containing IEEE NaN ("Not a Number") code
           set datafile missing "NaN"

   Example:
           set style data linespoints
           plot '-'
              1 10
              2 20
              3 ?
              4 40
              5 50
              e
           set datafile missing "?"
           plot '-'
              1 10
              2 20
              3 ?
              4 40
              5 50
              e
           plot '-' using 1:2
              1 10
              2 20
              3 ?
              4 40
              5 50
              e
           plot '-' using 1:($2)
              1 10
              2 20
              3 ?
              4 40
              5 50
              e

   The first `plot` will recognize only the first datum in the "3 ?"
line.  It will use the single-datum-on-a-line convention that the line
number is "x" and the datum is "y", so the point will be plotted (in
this case erroneously) at (2,3).

   The second and third `plot` commands will correctly ignore the
middle line.  The plotted line will connect the points at (2,20) and
(4,40).

   The fourth `plot` will also correctly ignore the middle line, but
the plotted line will not connect the points at (2,20) and (4,40).

   There is no default character for `missing`, but in many cases any
non-parsible string of characters found where a numerical value is
expected will be treated as missing data.


File: gnuplot.info,  Node: set_datafile_separator,  Next: set_datafile_commentschars,  Prev: set_datafile_missing,  Up: datafile

3.25.16.4 set datafile separator
................................

The command `set datafile separator "<char>"` tells `gnuplot` that data
fields in subsequent input files are separated by <char> rather than by
whitespace.  The most common use is to read in csv (comma-separated
value) files written by spreadsheet or database programs. By default
data fields are separated by whitespace.

   Syntax:
           set datafile separator {"<char>" | whitespace}

   Examples:
           # Input file contains tab-separated fields
           set datafile separator "\t"

           # Input file contains comma-separated values fields
           set datafile separator ","


File: gnuplot.info,  Node: set_datafile_commentschars,  Next: set_datafile_binary,  Prev: set_datafile_separator,  Up: datafile

3.25.16.5 set datafile commentschars
....................................

The `set datafile commentschars` command allows you to tell `gnuplot`
what characters are used in a data file to denote comments.  Gnuplot
will ignore rest of the line behind the specified characters if either
of them is the first non-blank character on the line.

   Syntax:
           set datafile commentschars {"<string>"}
           show datafile commentschars
           unset commentschars

   Default value of the string is "#!" on VMS and "#" otherwise.

   Then, the following line in a data file is completely ignored
         # 1 2 3 4

   but the following
         1 # 3 4

   produces rather unexpected plot unless
         set datafile missing '#'

   is specified as well.

   Example:
           set datafile commentschars "#!%"


File: gnuplot.info,  Node: set_datafile_binary,  Prev: set_datafile_commentschars,  Up: datafile

3.25.16.6 set datafile binary
.............................

The *note binary:: command is used to set the defaults when reading
binary data files.  The syntax matches precisely that used for commands
`plot` and `splot`.  See *note matrix:: and *note general:: for details
about the keywords that can be present in <binary list>.

   Syntax:
           set datafile binary <binary list>
           show datafile binary
           show datafile
           unset datafile

   Examples:
           set datafile binary filetype=auto
           set datafile binary array=(512,512) format="%uchar"

           show datafile binary   # list current settings


File: gnuplot.info,  Node: decimalsign,  Next: dgrid3d,  Prev: datafile,  Up: set-show

3.25.17 decimalsign
-------------------

The *note decimalsign:: command selects a decimal sign for numbers
printed into tic labels or `set label` strings.

   Syntax:
           set decimalsign {<value> | locale {"<locale>"}}
           unset decimalsign
           show decimalsign

   The argument <value> is a string to be used in place of the usual
decimal point. Typical choices include the period, '.', and the comma,
',', but others may be useful, too.  If you omit the <value> argument,
the decimal separator is not modified from the usual default, which is
a period.  Unsetting decimalsign has the same effect as omitting
<value>.

   Example:

   Correct typesetting in most European countries requires:
           set decimalsign ','

   Please note: If you set an explicit string, this affects only
numbers that are printed using gnuplot's gprintf() formatting routine,
include axis tics.  It does not affect the format expected for input
data, and it does not affect numbers printed with the sprintf()
formatting routine. To change the behavior of both input and output
formatting, instead use the form

           set decimalsign locale

   This instructs the program to use both input and output formats in
accordance with the current setting of the LC_ALL, LC_NUMERIC, or LANG
environmental variables.

           set decimalsign locale "foo"

   This instructs the program to format all input and output in
accordance with locale "foo", which must be installed.  If locale "foo"
is not found then an error message is printed and the decimal sign
setting is unchanged.  On linux systems you can get a list of the
locales installed on your machine by typing "locale -a". A typical
linux locale string is of the form "sl_SI.UTF-8".  A typical Windows
locale string is of the form "Slovenian_Slovenia.1250" or "slovenian".
Please note that interpretation of the locale settings is done by the C
library at runtime. Older C libraries may offer only partial support for
locale settings such as the thousands grouping separator character.

           set decimalsign locale; set decimalsign "."

   This sets all input and output to use whatever decimal sign is
correct for the current locale, but over-rides this with an explicit
'.' in numbers formatted using gnuplot's internal gprintf() function.


File: gnuplot.info,  Node: dgrid3d,  Next: dummy,  Prev: decimalsign,  Up: set-show

3.25.18 dgrid3d
---------------

The *note dgrid3d:: command enables, and can set parameters for,
non-grid to grid data mapping.  See `splot grid_data` for more details
about the grid data structure.

   Syntax:
           set dgrid3d {<rows>} {,{<cols>}}
                       { splines |
                         qnorm {<norm>} |
                         (gauss | cauchy | exp | box | hann)
                           {kdensity} {<dx>} {,<dy>} }
           unset dgrid3d
           show dgrid3d

   By default *note dgrid3d:: is disabled.  When enabled, 3D data read
from a file are always treated as a scattered data set.  A grid with
dimensions derived from a bounding box of the scattered data and size
as specified by the row/col_size parameters is created for plotting and
contouring.  The grid is equally spaced in x (rows) and in y (columns);
the z values are computed as weighted averages or spline interpolations
of the scattered points' z values. In other words, a regularly spaced
grid is created and the a smooth approximation to the raw data is
evaluated for all grid points. This approximation is plotted in place
of the raw data.

   The number of columns defaults to the number of rows, which defaults
to 10.

   Several algorithms are available to calculate the approximation from
the raw data. Some of these algorithms can take additional parameters.
These interpolations are such the closer the data point is to a grid
point, the more effect it has on that grid point.

   The `splines` algorithm calculates an interpolation based on "thin
plate splines". It does not take additional parameters.

   The `qnorm` algorithm calculates a weighted average of the input
data at each grid point. Each data point is weighted inversely by its
distance from the grid point raised to the norm power.  (Actually, the
weights are given by the inverse of dx^norm + dy^norm, where dx and dy
are the components of the separation of the grid point from each data
point.  For some norms that are powers of two, specifically 4, 8, and
16, the computation is optimized by using the Euclidean distance in the
weight calculation, (dx^2+dy^2)^norm/2.  However, any non-negative
integer can be used.)  The power of the norm can be specified as a
single optional parameter.  This algorithm is the default.

   Finally, several smoothing kernels are available to calculate
weighted averages: z = Sum_i w(d_i) * z_i / Sum_i w(d_i), where z_i is
the value of the i-th data point and d_i is the distance between the
current grid point and the location of the i-th data point. All kernels
assign higher weights to data points that are close to the current grid
point and lower weights to data points further away.

   The following kernels are available:
           gauss :     w(d) = exp(-d*d)
           cauchy :    w(d) = 1/(1 + d*d)
           exp :       w(d) = exp(-d)
           box :       w(d) = 1                     if d<1
                            = 0                     otherwise
           hann :      w(d) = 0.5*(1-cos(2*pi*d))   if d<1
                       w(d) = 0                     otherwise

   When using one of these five smoothing kernels, up to two additional
numerical parameters can be specified: dx and dy. These are used to
rescale the coordinate differences when calculating the distance: d_i =
sqrt( ((x-x_i)/dx)**2 + ((y-y_i)/dy)**2 ), where x,y are the
coordinates of the current grid point and x_i,y_i are the coordinates
of the i-th data point. The value of dy defaults to the value of dx,
which defaults to 1. The parameters dx and dy make it possible to
control the radius over which data points contribute to a grid point IN
THE UNITS OF THE DATA ITSELF.

   The optional keyword `kdensity2d`, which must come after the name of
the kernel, but before the (optional) scale parameters, modifies the
algorithm so that the values calculated for the grid points are not
divided by the sum of the weights ( z = Sum_i w(d_i) * z_i ). If all
z_i are constant, this effectively plots a bivariate kernel density
estimate: a kernel function (one of the five defined above) is placed
at each data point, the sum of these kernels is evaluated at every grid
point, and this smooth surface is plotted instead of the original data.
This is similar in principle to + what the `smooth kdensity` option
does to 1D datasets.  (See kdensity2d.dem for usage demo)

   A slightly different syntax is also supported for reasons of
backwards compatibility. If no interpolation algorithm has been
explicitly selected, the `qnorm` algorithm is assumed. Up to three
comma-separated, optional parameters can be specified, which are
interpreted as the the number of rows, the number of columns, and the
norm value, respectively.

   The *note dgrid3d:: option is a simple scheme which replaces
scattered data with weighted averages on a regular grid.  More
sophisticated approaches to this problem exist and should be used to
preprocess the data outside `gnuplot` if this simple solution is found
inadequate.

   See also dgrid3d.dem: dgrid3d demo.
(http://www.gnuplot.info/demo/dgrid3d.html) and scatter.dem: dgrid3d
demo. (http://www.gnuplot.info/demo/scatter.html)


File: gnuplot.info,  Node: dummy,  Next: encoding,  Prev: dgrid3d,  Up: set-show

3.25.19 dummy
-------------

The *note dummy:: command changes the default dummy variable names.

   Syntax:
           set dummy {<dummy-var>} {,<dummy-var>}
           show dummy

   By default, `gnuplot` assumes that the independent, or "dummy",
variable for the `plot` command is "t" if in parametric or polar mode,
or "x" otherwise.  Similarly the independent variables for the `splot`
command are "u" and "v" in parametric mode (`splot` cannot be used in
polar mode), or "x" and "y" otherwise.

   It may be more convenient to call a dummy variable by a more
physically meaningful or conventional name.  For example, when plotting
time functions:

           set dummy t
           plot sin(t), cos(t)

   At least one dummy variable must be set on the command; *note
dummy:: by itself will generate an error message.

   Examples:
           set dummy u,v
           set dummy ,s

   The second example sets the second variable to s.


File: gnuplot.info,  Node: encoding,  Next: fit_,  Prev: dummy,  Up: set-show

3.25.20 encoding
----------------

The *note encoding:: command selects a character encoding.  Syntax:
           set encoding {<value>}
           set encoding locale
           show encoding

   Valid values are
        default     - tells a terminal to use its default encoding
        iso_8859_1  - the most common Western European encoding used by many
                      Unix workstations and by MS-Windows. This encoding is
                      known in the PostScript world as 'ISO-Latin1'.
        iso_8859_15 - a variant of iso_8859_1 that includes the Euro symbol
        iso_8859_2  - used in Central and Eastern Europe
        iso_8859_9  - used in Turkey (also known as Latin5)
        koi8r       - popular Unix cyrillic encoding
        koi8u       - ukrainian Unix cyrillic encoding
        cp437       - codepage for MS-DOS
        cp850       - codepage for OS/2, Western Europe
        cp852       - codepage for OS/2, Central and Eastern Europe
        cp950       - MS version of Big5 (emf terminal only)
        cp1250      - codepage for MS Windows, Central and Eastern Europe
        cp1251      - codepage for 8-bit Russian, Serbian, Bulgarian, Macedonian
        cp1254      - codepage for MS Windows, Turkish (superset of Latin5)
        sjis        - shift-JIS Japanese encoding
        utf8        - variable-length (multibyte) representation of Unicode
                      entry point for each character

   The command *note locale:: is different from the other options.  It
attempts to determine the current locale from the runtime environment.
On most systems this is controlled by the environmental variables
LC_ALL, LC_CTYPE, or LANG.  This mechanism is necessary, for example, to
pass multibyte character encodings such as UTF-8 or EUC_JP to the wxt
and cairopdf terminals.  This command does not affect the
locale-specific representation of dates or numbers.  See also *note
locale:: and *note decimalsign::.

   Generally you must set the encoding before setting the terminal type.
Note that encoding is not supported by all terminal drivers and that
the device must be able to produce the desired non-standard characters.


File: gnuplot.info,  Node: fit_,  Next: fontpath,  Prev: encoding,  Up: set-show

3.25.21 fit
-----------

The *note fit:: setting defines where the *note fit:: command writes
its output.

   Syntax:
           set fit {logfile {"<filename>"}} {{no}errorvariables} {{no}quiet}
           unset fit
           show fit

   The <filename> argument must be enclosed in single or double quotes.

   If no filename is given or *note fit:: is used the log file is reset
to its default value "fit.log" or the value of the environmental
variable `FIT_LOG`.

   If the given logfile name ends with a / or \, it is interpreted to be
a directory name, and the actual filename will be "fit.log" in that
directory.

   If the `errorvariables` option is turned on, the error of each fitted
parameter computed by *note fit:: will be copied to a user-defined
variable whose name is formed by appending "_err" to the name of the
parameter itself.  This is useful mainly to put the parameter and its
error onto a plot of the data and the fitted function, for reference,
as in:

            set fit errorvariables
            fit f(x) 'datafile' using 1:2 via a, b
            print "error of a is:", a_err
            set label 'a=%6.2f', a, '+/- %6.2f', a_err
            plot 'datafile' using 1:2, f(x)

   By default the information written to the log file is also echoed to
the terminal session. `set fit quiet` turns off the echo.


File: gnuplot.info,  Node: fontpath,  Next: format_,  Prev: fit_,  Up: set-show

3.25.22 fontpath
----------------

The *note fontpath:: setting defines additional locations for font files
searched when including font files. Currently only the postscript
terminal supports *note fontpath::. If a file cannot be found in the
current directory, the directories in *note fontpath:: are tried.
Further documentation concerning the supported file formats is included
in the `terminal postscript` section of the documentation.

   Syntax:
           set fontpath {"pathlist1" {"pathlist2"...}}
           show fontpath

   Path names may be entered as single directory names, or as a list of
path names separated by a platform-specific path separator, eg. colon
(':') on Unix, semicolon (';') on DOS/Windows/OS/2 platforms.  The
*note fontpath::, *note save:: and `save set` commands replace the
platform-specific separator with a space character (' ') for maximum
portability. If a directory name ends with an exclamation mark ('!')
also the subdirectories of this directory are searched for font files.

   If the environmental variable GNUPLOT_FONTPATH is set, its contents
are appended to *note fontpath::.  If it is not set, a system dependent
default value is used. It is set by testing several directories for
existence when using the fontpath the first time. Thus, the first call
of *note fontpath::, *note fontpath::, *note fontpath::, `plot`, or
`splot` with embedded font files takes a little more time. If you want
to save this time you may set the environmental variable
GNUPLOT_FONTPATH since probing is switched off, then. You can find out
which is the default fontpath by using *note fontpath::.

   *note fontpath:: prints the contents of the user-defined fontpath
and the system fontpath separately.  However, the *note save:: and
`save set` commands save only the user-specified parts of *note
fontpath::.

   For terminal drivers that access fonts by filename via the gd
library, the font search path is controlled by the environmental
variable GDFONTPATH.


File: gnuplot.info,  Node: format_,  Next: function_style,  Prev: fontpath,  Up: set-show

3.25.23 format
--------------

The format of the tic-mark labels can be set with the `set format`
command or with the `set tics format` or individual `set {axis}tics
format` commands.

   Syntax:
           set format {<axes>} {"<format-string>"}
           set format {<axes>} {'<format-string>'}
           show format

   where <axes> is either `x`, `y`, `xy`, `x2`, `y2`, `z`, `cb` or
nothing (which applies the format to all axes). The following two
commands are equivalent:
           set format y "%.2f"
           set ytics format "%.2f"

   The length of the string is restricted to 100 characters.  The
default format is "% g", but other formats such as "%.2f" or "%3.0em"
are often desirable.  The format "$%g$" is often desirable for LaTeX.
If no format string is given, the format will be returned to the
default.  If the empty string "" is given, tics will have no labels,
although the tic mark will still be plotted.  To eliminate the tic
marks, use `unset xtics` or `set tics scale 0`.

   Newline (\n) and enhanced text markup is accepted in the format
string.  Use double-quotes rather than single-quotes in this case.  See
also `syntax`.  Characters not preceded by "%" are printed verbatim.
Thus you can include spaces and labels in your format string, such as
"%g m", which will put " m" after each number.  If you want "%" itself,
double it: "%g %%".

   See also `set xtics` for more information about tic labels, and
*note decimalsign:: for how to use non-default decimal separators in
numbers printed this way.  See also electron demo (electron.dem).
(http://www.gnuplot.info/demo/electron.html)

* Menu:

* gprintf_::
* format_specifiers::
* time/date_specifiers::


File: gnuplot.info,  Node: gprintf_,  Next: format_specifiers,  Prev: format_,  Up: format_

3.25.23.1 gprintf
.................

The string function gprintf("format",x) uses gnuplot's own format
specifiers, as do the gnuplot commands `set format`, *note timestamp::,
and others. These format specifiers are not the same as those used by
the standard C-language routine sprintf(). gprintf() accepts only a
single variable to be formatted.  Gnuplot also provides an
sprintf("format",x1,x2,...) routine if you prefer.  For a list of
gnuplot's format options, see `format specifiers`.


File: gnuplot.info,  Node: format_specifiers,  Next: time/date_specifiers,  Prev: gprintf_,  Up: format_

3.25.23.2 format specifiers
...........................

The acceptable formats (if not in time/date mode) are:

           Format       Explanation
           %f           floating point notation
           %e or %E     exponential notation; an "e" or "E" before the power
           %g or %G     the shorter of %e (or %E) and %f
           %x or %X     hex
           %o or %O     octal
           %t           mantissa to base 10
           %l           mantissa to base of current logscale
           %s           mantissa to base of current logscale; scientific power
           %T           power to base 10
           %L           power to base of current logscale
           %S           scientific power
           %c           character replacement for scientific power
           %b           mantissa of ISO/IEC 80000 notation (ki, Mi, Gi, Ti, Pi, Ei, Zi, Yi)
           %B           prefix of ISO/IEC 80000 notation (ki, Mi, Gi, Ti, Pi, Ei, Zi, Yi)
           %P           multiple of pi

   A 'scientific' power is one such that the exponent is a multiple of
three.  Character replacement of scientific powers (`"%c"`) has been
implemented for powers in the range -18 to +18.  For numbers outside of
this range the format reverts to exponential.

   Other acceptable modifiers (which come after the "%" but before the
format specifier) are "-", which left-justifies the number; "+", which
forces all numbers to be explicitly signed; " " (a space), which makes
positive numbers have a space in front of them where negative numbers
have "-"; "#", which places a decimal point after floats that have only
zeroes following the decimal point; a positive integer, which defines
the field width; "0" (the digit, not the letter) immediately preceding
the field width, which indicates that leading zeroes are to be used
instead of leading blanks; and a decimal point followed by a
non-negative integer, which defines the precision (the minimum number
of digits of an integer, or the number of digits following the decimal
point of a float).

   Some systems may not support all of these modifiers but may also
support others; in case of doubt, check the appropriate documentation
and then experiment.

   Examples:
           set format y "%t"; set ytics (5,10)          # "5.0" and "1.0"
           set format y "%s"; set ytics (500,1000)      # "500" and "1.0"
           set format y "%+-12.3f"; set ytics(12345)    # "+12345.000  "
           set format y "%.2t*10^%+03T"; set ytic(12345)# "1.23*10^+04"
           set format y "%s*10^{%S}"; set ytic(12345)   # "12.345*10^{3}"
           set format y "%s %cg"; set ytic(12345)       # "12.345 kg"
           set format y "%.0P pi"; set ytic(6.283185)   # "2 pi"
           set format y "%.0f%%"; set ytic(50)          # "50%"

           set log y 2; set format y '%l'; set ytics (1,2,3)
           #displays "1.0", "1.0" and "1.5" (since 3 is 1.5 * 2^1)

   There are some problem cases that arise when numbers like 9.999 are
printed with a format that requires both rounding and a power.

   If the data type for the axis is time/date, the format string must
contain valid codes for the 'strftime' function (outside of `gnuplot`,
type "man strftime").  See *note timefmt:: for a list of the allowed
input format codes.


File: gnuplot.info,  Node: time/date_specifiers,  Prev: format_specifiers,  Up: format_

3.25.23.3 time/date specifiers
..............................

In time/date mode, the acceptable formats are:

           Format       Explanation
           %a           abbreviated name of day of the week
           %A           full name of day of the week
           %b or %h     abbreviated name of the month
           %B           full name of the month
           %d           day of the month, 01--31
           %D           shorthand for "%m/%d/%y" (only output)
           %F           shorthand for "%Y-%m-%d" (only output)
           %k           hour, 0--23 (one or two digits)
           %H           hour, 00--23 (always two digits)
           %l           hour, 1--12 (one or two digits)
           %I           hour, 01--12 (always two digits)
           %j           day of the year, 1--366
           %m           month, 01--12
           %M           minute, 0--60
           %p           "am" or "pm"
           %r           shorthand for "%I:%M:%S %p" (only output)
           %R           shorthand for "%H:%M" (only output)
           %s           number of seconds since the start of year 2000
           %S           second, integer 0--60 on output, (double) on input
           %T           shorthand for "%H:%M:%S" (only output)
           %U           week of the year (week starts on Sunday)
           %w           day of the week, 0--6 (Sunday = 0)
           %W           week of the year (week starts on Monday)
           %y           year, 0-68 for 2000-2068, 69-99 for 1969-1999
           %Y           year, 4-digit

   Except for the non-numerical formats, these may be preceded by a "0"
("zero", not "oh") to pad the field length with leading zeroes, and a
positive digit, to define the minimum field width (which will be
overridden if the specified width is not large enough to contain the
number).  The %S format also accepts a precision specifier so that
fractional seconds can be written.  There is a 24-character limit to
the length of the printed text; longer strings will be truncated.

   Examples:

   Suppose the text is "76/12/25 23:11:11".  Then
           set format x                 # defaults to "12/25/76" \n "23:11"
           set format x "%A, %d %b %Y"  # "Saturday, 25 Dec 1976"
           set format x "%r %D"         # "11:11:11 pm 12/25/76"

   Suppose the text is "98/07/06 05:04:03.123456".  Then
           set format x "%1y/%2m/%3d %01H:%02M:%06.3S"  # "98/ 7/  6 5:04:03.123"


File: gnuplot.info,  Node: function_style,  Next: functions_,  Prev: format_,  Up: set-show

3.25.24 function style
----------------------

This form of the command is deprecated. Please see `set style function`.


File: gnuplot.info,  Node: functions_,  Next: grid,  Prev: function_style,  Up: set-show

3.25.25 functions
-----------------

The *note functions:: command lists all user-defined functions and their
definitions.

   Syntax:
           show functions

   For information about the definition and usage of functions in
`gnuplot`, please see `expressions`.  See also splines as user defined
functions (spline.dem) (http://www.gnuplot.info/demo/spline.html) and
use of functions and complex variables for airfoils (airfoil.dem).
(http://www.gnuplot.info/demo/airfoil.html)


File: gnuplot.info,  Node: grid,  Next: hidden3d,  Prev: functions_,  Up: set-show

3.25.26 grid
------------

The `set grid` command allows grid lines to be drawn on the plot.

   Syntax:
           set grid {{no}{m}xtics} {{no}{m}ytics} {{no}{m}ztics}
                    {{no}{m}x2tics} {{no}{m}y2tics}
                    {{no}{m}cbtics}
                    {polar {<angle>}}
                    {layerdefault | front | back}
                    { {linestyle <major_linestyle>}
                      | {linetype | lt <major_linetype>}
                        {linewidth | lw <major_linewidth>}
                      { , {linestyle | ls <minor_linestyle>}
                          | {linetype | lt <minor_linetype>}
                            {linewidth | lw <minor_linewidth>} } }
           unset grid
           show grid

   The grid can be enabled and disabled for the major and/or minor tic
marks on any axis, and the linetype and linewidth can be specified for
major and minor grid lines, also via a predefined linestyle, as far as
the active terminal driver supports this.

   Additionally, a polar grid can be selected for 2D plots--circles are
drawn to intersect the selected tics, and radial lines are drawn at
definable intervals.  (The interval is given in degrees or radians,
depending on the *note angles:: setting.)  Note that a polar grid is no
longer automatically generated in polar mode.

   The pertinent tics must be enabled before `set grid` can draw them;
`gnuplot` will quietly ignore instructions to draw grid lines at
non-existent tics, but they will appear if the tics are subsequently
enabled.

   If no linetype is specified for the minor gridlines, the same
linetype as the major gridlines is used.  The default polar angle is 30
degrees.

   If `front` is given, the grid is drawn on top of the graphed data. If
`back` is given, the grid is drawn underneath the graphed data. Using
`front` will prevent the grid from being obscured by dense data. The
default setup, `layerdefault`, is equivalent to `back` for 2D plots.
In 3D plots the default is to split up the grid and the graph box into
two layers: one behind, the other in front of the plotted data and
functions. Since *note hidden3d:: mode does its own sorting, it ignores
all grid drawing order options and passes the grid lines through the
hidden line removal machinery instead. These options actually affect
not only the grid, but also the lines output by *note border:: and the
various ticmarks (see `set xtics`).

   Z grid lines are drawn on the bottom of the plot.  This looks better
if a partial box is drawn around the plot--see *note border::.


File: gnuplot.info,  Node: hidden3d,  Next: historysize,  Prev: grid,  Up: set-show

3.25.27 hidden3d
----------------

The *note hidden3d:: command enables hidden line removal for surface
plotting (see `splot`).  Some optional features of the underlying
algorithm can also be controlled using this command.

   Syntax:
           set hidden3d {defaults} |
                        { {front|back}
                          {{offset <offset>} | {nooffset}}
                          {trianglepattern <bitpattern>}
                          {{undefined <level>} | {noundefined}}
                          {{no}altdiagonal}
                          {{no}bentover} }
           unset hidden3d
           show hidden3d

   In contrast to the usual display in gnuplot, hidden line removal
actually treats the given function or data grids as real surfaces that
can't be seen through, so plot elements behind the surface will be
hidden by it.  For this to work, the surface needs to have 'grid
structure' (see *note datafile:: about this), and it has to be drawn
`with lines` or *note linespoints::.

   When *note hidden3d:: is set, both the hidden portion of the surface
and possibly its contours drawn on the base (see *note contour::) as
well as the grid will be hidden.  Each surface has its hidden parts
removed with respect to itself and to other surfaces, if more than one
surface is plotted.  Contours drawn on the surface (*note surface::)
don't work.

   Labels and arrows are always visible and are unaffected.  The key
box is never hidden by the surface. As of gnuplot version 4.6, hidden3d
also affects 3D plotting styles `points`, *note labels::, *note
vectors::, and *note impulses:: even if no surface is present in the
graph.  Individual plots within the graph may be explicitly excluded
from this processing by appending the extra option `nohidden3d` to the
*note with:: specifier.

   Hidden3d does not affect solid surfaces drawn using the pm3d mode.
To achieve a similar effect purely for pm3d surfaces, use instead `set
pm3d depthorder`.  To mix pm3d surfaces with normal *note hidden3d::
processing, use the option `set hidden3d front` to force all elements
included in hidden3d processing to be drawn after any remaining plot
elements. Then draw the surface twice, once `with lines lt -2` and a
second time *note pm3d::. The first instance will include the surface
during calculation of occluded elements but will not draw the surface
itself.

   Functions are evaluated at isoline intersections.  The algorithm
interpolates linearly between function points or data points when
determining the visible line segments.  This means that the appearance
of a function may be different when plotted with *note hidden3d:: than
when plotted with `nohidden3d` because in the latter case functions are
evaluated at each sample.  Please see *note samples:: and *note
isosamples:: for discussion of the difference.

   The algorithm used to remove the hidden parts of the surfaces has
some additional features controllable by this command.  Specifying
`defaults` will set them all to their default settings, as detailed
below.  If `defaults` is not given, only explicitly specified options
will be influenced: all others will keep their previous values, so you
can turn on/off hidden line removal via `set {no}hidden3d`, without
modifying the set of options you chose.

   The first option, `offset`, influences the linetype used for lines
on the 'back' side.  Normally, they are drawn in a linetype one index
number higher than the one used for the front, to make the two sides of
the surface distinguishable.  You can specify a different linetype
offset to add instead of the default 1, by `offset <offset>`.  Option
`nooffset` stands for `offset 0`, making the two sides of the surface
use the same linetype.

   Next comes the option `trianglepattern <bitpattern>`.  <bitpattern>
must be a number between 0 and 7, interpreted as a bit pattern.  Each
bit determines the visibility of one edge of the triangles each surface
is split up into.  Bit 0 is for the 'horizontal' edges of the grid, Bit
1 for the 'vertical' ones, and Bit 2 for the diagonals that split each
cell of the original grid into two triangles.  The default pattern is
3, making all horizontal and vertical lines visible, but not the
diagonals.  You may want to choose 7 to see those diagonals as well.

   The `undefined <level>` option lets you decide what the algorithm is
to do with data points that are undefined (missing data, or undefined
function values), or exceed the given x-, y- or z-ranges.  Such points
can either be plotted nevertheless, or taken out of the input data set.
All surface elements touching a point that is taken out will be taken
out as well, thus creating a hole in the surface.  If <level> = 3,
equivalent to option `noundefined`, no points will be thrown away at
all.  This may produce all kinds of problems elsewhere, so you should
avoid this.  <level> = 2 will throw away undefined points, but keep the
out-of-range ones.  <level> = 1, the default, will get rid of
out-of-range points as well.

   By specifying `noaltdiagonal`, you can override the default handling
of a special case can occur if `undefined` is active (i.e. <level> is
not 3).  Each cell of the grid-structured input surface will be divided
in two triangles along one of its diagonals.  Normally, all these
diagonals have the same orientation relative to the grid.  If exactly
one of the four cell corners is excluded by the `undefined` handler,
and this is on the usual diagonal, both triangles will be excluded.
However if the default setting of `altdiagonal` is active, the other
diagonal will be chosen for this cell instead, minimizing the size of
the hole in the surface.

   The `bentover` option controls what happens to another special case,
this time in conjunction with the `trianglepattern`.  For rather
crumply surfaces, it can happen that the two triangles a surface cell
is divided into are seen from opposite sides (i.e. the original
quadrangle is 'bent over'), as illustrated in the following ASCII art:

                                                                   C----B
         original quadrangle:  A--B      displayed quadrangle:     |\   |
           ("set view 0,0")    | /|    ("set view 75,75" perhaps)  | \  |
                               |/ |                                |  \ |
                               C--D                                |   \|
                                                                   A    D

   If the diagonal edges of the surface cells aren't generally made
visible by bit 2 of the <bitpattern> there, the edge CB above wouldn't
be drawn at all, normally, making the resulting display hard to
understand.  Therefore, the default option of `bentover` will turn it
visible in this case.  If you don't want that, you may choose
`nobentover` instead.  See also hidden line removal demo (hidden.dem)
(http://www.gnuplot.info/demo/hidden.html) and complex hidden line demo
(singulr.dem). (http://www.gnuplot.info/demo/singulr.html)


File: gnuplot.info,  Node: historysize,  Next: isosamples,  Prev: hidden3d,  Up: set-show

3.25.28 historysize
-------------------

Note: the command *note historysize:: is only available when gnuplot
has been configured to use the GNU readline library.

   Syntax:
           set historysize <int>
           unset historysize

   When leaving gnuplot, the value of historysize is used for
truncating the history to at most that much lines. The default is 500.
*note historysize:: will disable history truncation and thus allow an
infinite number of lines to be written to the history file.


File: gnuplot.info,  Node: isosamples,  Next: key,  Prev: historysize,  Up: set-show

3.25.29 isosamples
------------------

The isoline density (grid) for plotting functions as surfaces may be
changed by the *note isosamples:: command.

   Syntax:
           set isosamples <iso_1> {,<iso_2>}
           show isosamples

   Each function surface plot will have <iso_1> iso-u lines and <iso_2>
iso-v lines.  If you only specify <iso_1>, <iso_2> will be set to the
same value as <iso_1>.  By default, sampling is set to 10 isolines per
u or v axis.  A higher sampling rate will produce more accurate plots,
but will take longer.  These parameters have no effect on data file
plotting.

   An isoline is a curve parameterized by one of the surface parameters
while the other surface parameter is fixed.  Isolines provide a simple
means to display a surface.  By fixing the u parameter of surface
s(u,v), the iso-u lines of the form c(v) = s(u0,v) are produced, and by
fixing the v parameter, the iso-v lines of the form c(u) = s(u,v0) are
produced.

   When a function surface plot is being done without the removal of
hidden lines, *note samples::  controls the number of points sampled
along each isoline;  see *note samples:: and *note hidden3d::. The
contour algorithm assumes that a function sample occurs at each isoline
intersection, so change in *note samples:: as well as *note
isosamples:: may be desired when changing the resolution of a function
surface/contour.


File: gnuplot.info,  Node: key,  Next: label,  Prev: isosamples,  Up: set-show

3.25.30 key
-----------

The `set key` command enables a key (or legend) describing plots on a
plot.

   The contents of the key, i.e., the names given to each plotted data
set and function and samples of the lines and/or symbols used to
represent them, are determined by the *note title:: and *note with::
options of the {`s`}`plot` command.  Please see *note title:: and *note
with:: for more information.

   Syntax:
           set key {on|off} {default}
                   {{inside | outside} | {lmargin | rmargin | tmargin | bmargin}
                     | {at <position>}}
                   {left | right | center} {top | bottom | center}
                   {vertical | horizontal} {Left | Right}
                   {{no}opaque}
                   {{no}reverse} {{no}invert}
                   {samplen <sample_length>} {spacing <vertical_spacing>}
                   {width <width_increment>}
                   {height <height_increment>}
                   {{no}autotitle {columnheader}}
                   {title "<text>"} {{no}enhanced}
                   {font "<face>,<size>"} {textcolor <colorspec>}
                   {{no}box { {linestyle | ls <line_style>}
                              | {linetype | lt <line_type>}
                                {linewidth | lw <line_width>}}}
                   {maxcols {<max no. of columns> | auto}}
                   {maxrows {<max no. of rows> | auto}}
           unset key
           show key

   The key contains a title and a sample (line, point, box) for each
plot in the graph. The key may be turned off by requesting `set key
off` or `unset key`.  Individual key entries may be turned off by using
the `notitle` keyword in the corresponding plot command.

   Elements within the key are stacked according to `vertical` or
`horizontal`.  In the case of `vertical`, the key occupies as few
columns as possible.  That is, elements are aligned in a column until
running out of vertical space at which point a new column is started.
The vertical space may be limited using 'maxrows'.  In the case of
`horizontal`, the key occupies as few rows as possible.  The horizontal
space may be limited using 'maxcols'.

   By default the key is placed in the upper right inside corner of the
graph.  The keywords `left`, `right`, `top`, `bottom`, `center`,
`inside`, `outside`, *note lmargin::, *note rmargin::, *note tmargin::,
*note bmargin:: (, `above`, `over`, `below` and `under`) may be used to
automatically place the key in other positions of the graph.  Also an
`at <position>` may be given to indicate precisely where the plot
should be placed.  In this case, the keywords `left`, `right`, `top`,
`bottom` and `center` serve an analogous purpose for alignment.  For
more information, see `key placement`.

   Justification of the plot titles within the key is controlled by
`Left` or `Right` (default).  The text and sample can be reversed
(`reverse`) and a box can be drawn around the key (`box {...}`) in a
specified `linetype` and `linewidth`, or a user-defined `linestyle`.

   By default the key is built up one plot at a time. That is, the key
symbol and title are drawn at the same time as the corresponding plot.
That means newer plots may sometimes place elements on top of the key.
`set key opaque` causes the key to be generated after all the plots.
In this case the key area is filled with background color and then the
key symbols and titles are written.  Therefore the key itself may
obscure portions of some plot elements.  The default can be restored by
`set key noopaque`.

   By default the first plot label is at the top of the key and
successive labels are entered below it. The `invert` option causes the
first label to be placed at the bottom of the key, with successive
labels entered above it. This option is useful to force the vertical
ordering of labels in the key to match the order of box types in a
stacked histogram.

   The <height_increment> is a number of character heights to be added
to or subtracted from the height of the key box.  This is useful mainly
when you are putting a box around the key and want larger borders
around the key entries.

   All plotted curves of `plot`s and `splot`s are titled according to
the default option `autotitles`. The automatic generation of titles can
be suppressed by `noautotitles`; then only those titles explicitly
defined by `(s)plot ... title ...` will be drawn.

   The command `set key autotitle columnheader` causes the first entry
in each column of input data to be interpreted as a text string and
used as a title for the corresponding plot. If the quantity being
plotted is a function of data from several columns, gnuplot may be
confused as to which column to draw the title from. In this case it is
necessary to specify the column explicitly in the plot command, e.g.

           plot "datafile" using (($2+$3)/$4) title columnhead(3) with lines

   An overall title can be put on the key (`title "<text>"`)--see also
`syntax` for the distinction between text in single- or double-quotes.
The key title uses the same justification as do the plot titles.

   The defaults for `set key` are `on`, `right`, `top`, `vertical`,
`Right`, `noreverse`, `noinvert`, `samplen 4`, `spacing 1.25`, `title
""`, and `nobox`.  The default <linetype> is the same as that used for
the plot borders.  Entering `set key default` returns the key to its
default configuration.

   The key is drawn as a sequence of lines, with one plot described on
each line.  On the right-hand side (or the left-hand side, if `reverse`
is selected) of each line is a representation that attempts to mimic
the way the curve is plotted.  On the other side of each line is the
text description (the line title), obtained from the `plot` command.
The lines are vertically arranged so that an imaginary straight line
divides the left- and right-hand sides of the key.  It is the
coordinates of the top of this line that are specified with the `set
key` command.  In a `plot`, only the x and y coordinates are used to
specify the line position.  For a `splot`, x, y and z are all used as a
3D location mapped using the same mapping as the graph itself to form
the required 2D screen position of the imaginary line.

   When using the TeX or other terminals where formatting information
is embedded in the string, `gnuplot` can only estimate the correctly
exact width of the string for key positioning.  If the key is to be
positioned at the left, it may be convenient to use the combination
`set key left Left reverse`.

   If `splot` is being used to draw contours, the contour labels will
be listed in the key.  If the alignment of these labels is poor or a
different number of decimal places is desired, the label format can be
specified.  See *note clabel:: for details.

   Examples:

   This places the key at the default location:
           set key default

   This disables the key:
           unset key

   This places a key at coordinates 2,3.5,2 in the default (first)
coordinate system:
           set key at 2,3.5,2

   This places the key below the graph:
           set key below

   This places the key in the bottom left corner, left-justifies the
text, gives it a title, and draws a box around it in linetype 3:
           set key left bottom Left title 'Legend' box 3

* Menu:

* key_placement::
* key_samples::


File: gnuplot.info,  Node: key_placement,  Next: key_samples,  Prev: key,  Up: key

3.25.30.1 key placement
.......................

To understand positioning, the best concept is to think of a region,
i.e., inside/outside, or one of the margins.  Along with the region,
keywords `left/center/right` (l/c/r) and `top/center/bottom` (t/c/b)
control where within the particular region the key should be placed.

   When in `inside` mode, the keywords `left` (l), `right` (r), `top`
(t), `bottom` (b), and `center` (c) push the key out toward the plot
boundary as illustrated:

          t/l   t/c   t/r

          c/l    c    c/r

          b/l   b/c   b/r

   When in `outside` mode, automatic placement is similar to the above
illustration, but with respect to the view, rather than the graph
boundary.  That is, a border is moved inward to make room for the key
outside of the plotting area, although this may interfere with other
labels and may cause an error on some devices.  The particular plot
border that is moved depends upon the position described above and the
stacking direction.  For options centered in one of the dimensions,
there is no ambiguity about which border to move.  For the corners,
when the stack direction is `vertical`, the left or right border is
moved inward appropriately.  When the stack direction is `horizontal`,
the top or bottom border is moved inward appropriately.

   The margin syntax allows automatic placement of key regardless of
stack direction.  When one of the margins *note lmargin:: (lm), *note
rmargin:: (rm), *note tmargin:: (tm), and *note bmargin:: (bm) is
combined with a single, non-conflicting direction keyword, the
following illustrated positions may contain the key:

               l/tm  c/tm  r/tm

          t/lm                  t/rm

          c/lm                  c/rm

          b/lm                  b/rm

               l/bm  c/bm  r/bm

   Keywords `above` and `over` are synonymous with *note tmargin::.
For version compatibility, `above` or `over` without an additional
l/c/r or stack direction keyword uses `center` and `horizontal`.
Keywords `below` and `under` are synonymous with *note bmargin::.  For
compatibility, `below` or `under` without an additional l/c/r or stack
direction keyword uses `center` and `horizontal`.  A further
compatibility issue is that `outside` appearing without an additional
t/b/c or stack direction keyword uses `top`, `right` and `vertical`
(i.e., the same as t/rm above).

   The <position> can be a simple x,y,z as in previous versions, but
these can be preceded by one of five keywords (`first`, `second`,
`graph`, `screen`, `character`) which selects the coordinate system in
which the position of the first sample line is specified.  See
`coordinates` for more details.  The effect of `left`, `right`, `top`,
`bottom`, and `center` when <position> is given is to align the key as
though it were text positioned using the label command, i.e., `left`
means left align with key to the right of <position>, etc.


File: gnuplot.info,  Node: key_samples,  Prev: key_placement,  Up: key

3.25.30.2 key samples
.....................

By default, each plot on the graph generates a corresponding entry in
the key.  This entry contains a plot title and a sample line/point/box
of the same color and fill properties as used in the plot itself.  The
font and textcolor properties control the appearance of the individual
plot titles that appear in the key. Setting the textcolor to "variable"
causes the text for each key entry to be the same color as the line or
fill color for that plot.  This was the default in some earlier
versions of gnuplot.

   The length of the sample line can be controlled by `samplen`.  The
sample length is computed as the sum of the tic length and
<sample_length> times the character width.  `samplen` also affects the
positions of point samples in the key since these are drawn at the
midpoint of the sample line, even if the sample line itself is not
drawn.

   The vertical spacing between lines is controlled by `spacing`.  The
spacing is set equal to the product of the pointsize, the vertical tic
size, and <vertical_spacing>.  The program will guarantee that the
vertical spacing is no smaller than the character height.

   The <width_increment> is a number of character widths to be added to
or subtracted from the length of the string.  This is useful only when
you are putting a box around the key and you are using control
characters in the text.  `gnuplot` simply counts the number of
characters in the string when computing the box width; this allows you
to correct it.


File: gnuplot.info,  Node: label,  Next: linetype,  Prev: key,  Up: set-show

3.25.31 label
-------------

Arbitrary labels can be placed on the plot using the `set label`
command.

   Syntax:
           set label {<tag>} {"<label text>"} {at <position>}
                     {left | center | right}
                     {norotate | rotate {by <degrees>}}
                     {font "<name>{,<size>}"}
                     {noenhanced}
                     {front | back}
                     {textcolor <colorspec>}
                     {point <pointstyle> | nopoint}
                     {offset <offset>}
           unset label {<tag>}
           show label

   The <position> is specified by either x,y or x,y,z, and may be
preceded by `first`, `second`, `graph`, `screen`, or `character` to
select the coordinate system.  See `coordinates` for details.

   The tag is an integer that is used to identify the label. If no <tag>
is given, the lowest unused tag value is assigned automatically.  The
tag can be used to delete or modify a specific label.  To change any
attribute of an existing label, use the `set label` command with the
appropriate tag, and specify the parts of the label to be changed.

   The <label text> can be a string constant, a string variable, or a
string- valued expression. See `strings`, *note sprintf::, and *note
gprintf::.

   By default, the text is placed flush left against the point x,y,z.
To adjust the way the label is positioned with respect to the point
x,y,z, add the justification parameter, which may be `left`, `right` or
`center`, indicating that the point is to be at the left, right or
center of the text.  Labels outside the plotted boundaries are
permitted but may interfere with axis labels or other text.

   If `rotate` is given, the label is written vertically (if the
terminal can do so, of course).  If `rotate by <degrees>` is given,
conforming terminals will try to write the text at the specified angle;
non-conforming terminals will treat this as vertical text.

   Font and its size can be chosen explicitly by `font
"<name>{,<size>}"` if the terminal supports font settings.  Otherwise
the default font of the terminal will be used.

   Normally the enhanced text mode string interpretation, if enabled
for the current terminal, is applied to all text strings including
label text.  The `noenhanced` property can be used to exempt a specific
label from the enhanced text mode processing.  The can be useful if the
label contains underscores, for example. See `enhanced text`.

   If `front` is given, the label is written on top of the graphed
data. If `back` is given (the default), the label is written underneath
the graphed data.  Using `front` will prevent a label from being
obscured by dense data.

   `textcolor <colorspec>` changes the color of the label text.
<colorspec> can be a linetype, an rgb color, or a palette mapping. See
help for *note colorspec:: and *note palette::.  `textcolor` may be
abbreviated `tc`.
        `tc default` resets the text color to its default state.
        `tc lt <n>` sets the text color to that of line type <n>.
        `tc ls <n>` sets the text color to that of line style <n>.
        `tc palette z` selects a palette color corresponding to the label z position.
        `tc palette cb <val>` selects a color corresponding to <val> on the colorbar.
        `tc palette fraction <val>`, with 0<=val<=1, selects a color corresponding to
            the mapping [0:1] to grays/colors of the *note palette::.
        `tc rgb "#RRGGBB"` selects an arbitrary 24-bit RGB color.

   If a <pointstyle> is given, using keywords `lt`, `pt` and `ps`, see
*note style::, a point with the given style and color of the given line
type is plotted at the label position and the text of the label is
displaced slightly.  This option is used by default for placing labels
in `mouse` enhanced terminals.  Use `nopoint` to turn off the drawing
of a point near the label (this is the default).

   The displacement defaults to 1,1 in *note pointsize:: units if a
<pointstyle> is given, 0,0 if no <pointstyle> is given.  The
displacement can be controlled by the optional `offset <offset>` where
<offset> is specified by either x,y or x,y,z, and may be preceded by
`first`, `second`, `graph`, `screen`, or `character` to select the
coordinate system.  See `coordinates` for details.

   If one (or more) axis is timeseries, the appropriate coordinate
should be given as a quoted time string according to the *note
timefmt:: format string.  See *note xdata:: and *note timefmt::.

   The EEPIC, Imagen, LaTeX, and TPIC drivers allow \\ in a string to
specify a newline.

   Label coordinates and text can also be read from a data file (see
*note labels::).

   Examples:

   To set a label at (1,2) to "y=x", use:
           set label "y=x" at 1,2

   To set a Sigma of size 24, from the Symbol font set, at the center of
the graph, use:
           set label "S" at graph 0.5,0.5 center font "Symbol,24"

   To set a label "y=x^2" with the right of the text at (2,3,4), and
tag the label as number 3, use:
           set label 3 "y=x^2" at 2,3,4 right

   To change the preceding label to center justification, use:
           set label 3 center

   To delete label number 2, use:
           unset label 2

   To delete all labels, use:
           unset label

   To show all labels (in tag order), use:
           show label

   To set a label on a graph with a timeseries on the x axis, use, for
example:
           set timefmt "%d/%m/%y,%H:%M"
           set label "Harvest" at "25/8/93",1

   To display a freshly fitted parameter on the plot with the data and
the fitted function, do this after the *note fit::, but before the
`plot`:
           set label sprintf("a = %3.5g",par_a) at 30,15
           bfit = gprintf("b = %s*10^%S",par_b)
           set label bfit at 30,20

   To display a function definition along with its fitted parameters,
use:
           f(x)=a+b*x
           fit f(x) 'datafile' via a,b
           set label GPFUN_f at graph .05,.95
           set label sprintf("a = %g", a) at graph .05,.90
           set label sprintf("b = %g", b) at graph .05,.85

   To set a label displaced a little bit from a small point:
           set label 'origin' at 0,0 point lt 1 pt 2 ps 3 offset 1,-1

   To set a label whose color matches the z value (in this case 5.5) of
some point on a 3D splot colored using pm3d:
           set label 'text' at 0,0,5.5 tc palette z


File: gnuplot.info,  Node: linetype,  Next: lmargin,  Prev: label,  Up: set-show

3.25.32 linetype
----------------

The `set linetype` command allows you to redefine the basic linetypes
used for plots.  The command options are identical to those for "set
style line".  Unlike line styles, redefinitions by `set linetype` are
persistent;  they are not affected by *note reset::.

   For example, linetypes one and two default to red and green. If you
redefine them like this:

           set linetype 1 lw 2 lc rgb "blue" pointtype 6
           set linetype 2 lw 2 lc rgb "forest-green" pointtype 8

   everywhere that uses lt 1 will now get a thick blue line rather than
a thin red line (the previous default meaning of lt 1).  This includes
uses such as the definition of a temporary linestyle derived from the
base linetype 1.

   `Note`: This command is new to gnuplot version 4.6.  It supersedes a
rather cryptic command in version 4.2 "set style increment user".  The
older command is now deprecated.

   This mechanism can be used to define a set of personal preferences
for the sequence of lines used in gnuplot.  The recommended way to do
this is to add to the run-time initialization file ~/.gnuplot a
sequence of commands like

           if ((GPVAL_VERSION < 4.5) \
           ||  (!strstrt(GPVAL_COMPILE_OPTIONS,"+USER_LINETYPES"))) \
               exit
           set linetype 1 lc rgb "dark-violet" lw 2 pt 0
           set linetype 2 lc rgb "sea-green"   lw 2 pt 7
           set linetype 3 lc rgb "cyan"        lw 2 pt 6 pi -1
           set linetype 4 lc rgb "dark-red"    lw 2 pt 5 pi -1
           set linetype 5 lc rgb "blue"        lw 2 pt 8
           set linetype 6 lc rgb "dark-orange" lw 2 pt 3
           set linetype 7 lc rgb "black"       lw 2 pt 11
           set linetype 8 lc rgb "goldenrod"   lw 2
           set linetype cycle 8

   Every time you run gnuplot the line types will be initialized to
these values.  You may initialize as many linetypes as you like. If you
do not redefine, say, linetype 3 then it will continue to have the
default properties (in this case blue, pt 3, lw 1, etc).  The first few
lines of the example script insure that the commands will be skipped by
older versions of gnuplot.

   Similar script files can be used to define theme-based color
choices, or sets of colors optimized for a particular plot type or
output device.

   The command `set linetype cycle 8` tells gnuplot to re-use these
definitions for the color and linewidth of higher-numbered linetypes.
That is, linetypes 9-16, 17-24, and so on will use this same sequence
of colors and widths.  The point properties (pointtype, pointsize,
pointinterval) are not affected by this command.  `unset linetype
cycle` disables this feature.  If the line properties of a higher
numbered linetype are explicitly defined, this takes precedence over
the recycled low-number linetype properties.


File: gnuplot.info,  Node: lmargin,  Next: loadpath,  Prev: linetype,  Up: set-show

3.25.33 lmargin
---------------

The command *note lmargin:: sets the size of the left margin.  Please
see *note margin:: for details.


File: gnuplot.info,  Node: loadpath,  Next: locale,  Prev: lmargin,  Up: set-show

3.25.34 loadpath
----------------

The *note loadpath:: setting defines additional locations for data and
command files searched by the *note call::, `load`, `plot` and `splot`
commands.  If a file cannot be found in the current directory, the
directories in *note loadpath:: are tried.

   Syntax:
           set loadpath {"pathlist1" {"pathlist2"...}}
           show loadpath

   Path names may be entered as single directory names, or as a list of
path names separated by a platform-specific path separator, eg. colon
(':') on Unix, semicolon (';') on DOS/Windows/OS/2 platforms.  The
*note loadpath::, *note save:: and `save set` commands replace the
platform-specific separator with a space character (' ').

   If the environment variable GNUPLOT_LIB is set, its contents are
appended to *note loadpath::.  However, *note loadpath:: prints the
contents of *note loadpath:: and GNUPLOT_LIB separately.  Also, the
*note save:: and `save set` commands ignore the contents of GNUPLOT_LIB.


File: gnuplot.info,  Node: locale,  Next: logscale,  Prev: loadpath,  Up: set-show

3.25.35 locale
--------------

The *note locale:: setting determines the language with which
`{x,y,z}{d,m}tics` will write the days and months.

   Syntax:
           set locale {"<locale>"}

   <locale> may be any language designation acceptable to your
installation.  See your system documentation for the available options.
The command `set locale ""` will try to determine the locale from the
LC_TIME, LC_ALL, or LANG environment variables.

   To change the decimal point locale, see *note decimalsign::.  To
change the character encoding to the current locale, see *note
encoding::.


File: gnuplot.info,  Node: logscale,  Next: macros,  Prev: locale,  Up: set-show

3.25.36 logscale
----------------

Syntax:
           set logscale <axes> {<base>}
           unset logscale <axes>
           show logscale

   where <axes> may be any combinations of `x`, `x2`, `y`, `y2`, `z`,
`cb`, and `r` in any order.  <base> is the base of the log scaling
(default is base 10).  If no axes are specified, the command affects
all axes except `r`.  The command *note logscale:: turns off log
scaling for all axes.  Note that the ticmarks generated for logscaled
axes are not uniformly spaced.  See `set xtics`.

   Examples:

   To enable log scaling in both x and z axes:
           set logscale xz

   To enable scaling log base 2 of the y axis:
           set logscale y 2

   To enable z and color log axes for a pm3d plot:
           set logscale zcb

   To disable z axis log scaling:
           unset logscale z


File: gnuplot.info,  Node: macros,  Next: mapping,  Prev: logscale,  Up: set-show

3.25.37 macros
--------------

If command line macro substitution is enabled, then tokens in the
command line of the form @<stringvariablename> will be replaced by the
text string contained in <stringvariablename>. See `substitution`.

   Syntax:
          set macros


File: gnuplot.info,  Node: mapping,  Next: margin,  Prev: macros,  Up: set-show

3.25.38 mapping
---------------

If data are provided to `splot` in spherical or cylindrical coordinates,
the *note mapping:: command should be used to instruct `gnuplot` how to
interpret them.

   Syntax:
           set mapping {cartesian | spherical | cylindrical}

   A cartesian coordinate system is used by default.

   For a spherical coordinate system, the data occupy two or three
columns (or *note using:: entries).  The first two are interpreted as
the azimuthal and polar angles theta and phi (or "longitude" and
"latitude"), in the units specified by *note angles::.  The radius r is
taken from the third column if there is one, or is set to unity if
there is no third column.  The mapping is:

           x = r * cos(theta) * cos(phi)
           y = r * sin(theta) * cos(phi)
           z = r * sin(phi)

   Note that this is a "geographic" spherical system, rather than a
"polar" one (that is, phi is measured from the equator, rather than the
pole).

   For a cylindrical coordinate system, the data again occupy two or
three columns.  The first two are interpreted as theta (in the units
specified by *note angles::) and z.  The radius is either taken from
the third column or set to unity, as in the spherical case.  The
mapping is:

           x = r * cos(theta)
           y = r * sin(theta)
           z = z

   The effects of *note mapping:: can be duplicated with the *note
using:: filter on the `splot` command, but *note mapping:: may be more
convenient if many data files are to be processed.  However even if
*note mapping:: is used, *note using:: may still be necessary if the
data in the file are not in the required order.

   *note mapping:: has no effect on `plot`.  world.dem: mapping demos.
(http://www.gnuplot.info/demo/world.html)


File: gnuplot.info,  Node: margin,  Next: mouse,  Prev: mapping,  Up: set-show

3.25.39 margin
--------------

The *note margin:: is the distance between the plot border and the
outer edge of the canvas. The size of the margin is chosen
automatically, but can be overridden by the *note margin:: commands.
*note margin:: shows the current settings.  To alter the distance
between the inside of the plot border and the data in the plot itself,
see *note offsets::.

   Syntax:
           set bmargin {{at screen} <margin>}
           set lmargin {{at screen} <margin>}
           set rmargin {{at screen} <margin>}
           set tmargin {{at screen} <margin>}
           show margin

   The default units of <margin> are character heights or widths, as
appropriate.  A positive value defines the absolute size of the margin.
A negative value (or none) causes `gnuplot` to revert to the computed
value.  For 3D plots, only the left margin can be set using character
units.

   The keywords `at screen` indicates that the margin is specified as a
fraction of the full drawing area. This can be used to precisely line
up the corners of individual 2D and 3D graphs in a multiplot. This
placement ignores the current values of *note origin:: and *note
size::, and is intended as an alternative method for positioning graphs
within a multiplot.

   Normally the margins of a plot are automatically calculated based on
tics, tic labels, axis labels, the plot title, the timestamp and the
size of the key if it is outside the borders.  If, however, tics are
attached to the axes (`set xtics axis`, for example), neither the tics
themselves nor their labels will be included in either the margin
calculation or the calculation of the positions of other text to be
written in the margin.  This can lead to tic labels overwriting other
text if the axis is very close to the border.


File: gnuplot.info,  Node: mouse,  Next: multiplot,  Prev: margin,  Up: set-show

3.25.40 mouse
-------------

The command `set mouse` enables mouse actions for the current
interactive terminal.  It is usually enabled by default in interactive
mode, but disabled by default if commands are being read from a file.

   There are two mouse modes. The 2D mode works for `plot` commands and
for `splot` maps (i.e. *note view:: with z-rotation 0, 90, 180, 270 or
360 degrees, including `set view map`).  In this mode the mouse
position is tracked and you can pan or zoom using the mouse buttons or
arrow keys.  Some terminals support toggling individual plots on/off by
clicking on the corresponding key title or on a separate widget.

   For 3D graphs `splot`, the view and scaling of the graph can be
changed with mouse buttons 1 and 2, respectively. A vertical motion of
Button 2 with the shift key held down changes the *note xyplane::.  If
additionally to these buttons the modifier <ctrl> is held down, the
coordinate axes are displayed but the data are suppressed.  This is
useful for large data sets.

   Mousing is not available inside multiplot mode. When multiplot is
completed using *note multiplot::, then the mouse will be turned on
again but acts only on the most recent plot within the multiplot (like
replot does).

   Syntax:
           set mouse {doubleclick <ms>} {nodoubleclick} \
                     {{no}zoomcoordinates} \
                     {noruler | ruler {at x,y}} \
                     {polardistance{deg|tan} | nopolardistance} \
                     {format <string>} \
                     {clipboardformat <int>/<string>} \
                     {mouseformat <int>/<string>} \
                     {{no}labels {"labeloptions"}} \
                     {{no}zoomjump} {{no}verbose}
           unset mouse

   The options `noruler` and `ruler` switch the ruler off and on, the
latter optionally setting the origin at the given coordinates. While
the ruler is on, the distance in user units from the ruler origin to
the mouse is displayed continuously. By default, toggling the ruler has
the key binding 'r'.

   The option `polardistance` determines if the distance between the
mouse cursor and the ruler is also shown in polar coordinates (distance
and angle in degrees or tangent (slope)). This corresponds to the
default key binding '5'.

   Choose the option *note labels:: to define persistent gnuplot labels
using Button 2.  The default is `nolabels`, which makes Button 2 draw
only a temporary label at the mouse position. Labels are drawn with the
current setting of *note mouseformat::.  The `labeloptions` string is
passed to the `set label` command.  The default is "point pointstyle 1"
which will plot a small plus at the label position.  Temporary labels
will disappear at the next *note replot:: or mouse zoom operation.
Persistent labels can be removed by holding the Ctrl-Key down while
clicking Button 2 on the label's point. The threshold for how close you
must be to the label is also determined by the *note pointsize::.

   If the option `verbose` is turned on the communication commands are
shown during execution. This option can also be toggled by hitting `6`
in the driver's window. `verbose` is off by default.

   Press 'h' in the driver's window for a short summary of the mouse
and key bindings.  This will also display user defined bindings or
`hotkeys` which can be defined using the `bind` command, see help for
`bind`.  Note, that user defined `hotkeys` may override the default
bindings.  See also help for `bind` and `label`.

* Menu:

* doubleclick::
* mouseformat::
* scrolling::
* X11_mouse::
* zoom::


File: gnuplot.info,  Node: doubleclick,  Next: mouseformat,  Prev: mouse,  Up: mouse

3.25.40.1 doubleclick
.....................

The doubleclick resolution is given in milliseconds and used for Button
1, which copies the current mouse position to the `clipboard`.  The
default value is 300 ms.  Setting the value to 0 ms triggers the copy
on a single click.


File: gnuplot.info,  Node: mouseformat,  Next: scrolling,  Prev: doubleclick,  Up: mouse

3.25.40.2 mouseformat
.....................

The `set mouse format` command specifies a format string for sprintf()
which determines how the mouse cursor [x,y] coordinates are printed to
the plot window and to the clipboard.  The default is "% #g".

   `set mouse clipboardformat` and *note mouseformat:: are used for
formatting the text on Button1 and Button2 actions - copying the
coordinates to the clipboard and temporarily annotating the mouse
position.  An integer argument selects one of the format options in the
table below. A string argument is used as a format for sprintf() in
option 6 and should contain two float specifiers.  Example:
          `set mouse mouseformat "mouse x,y = %5.2g, %10.3f"`.

   Use `set mouse mouseformat ""` to turn this string off again.

   The following formats are available:

      0   default (same as 1)
      1   axis coordinates                    1.23, 2.45
      2   graph coordinates (from 0 to 1)    /0.00, 1.00/
      3   x = timefmt     y = axis           [(as set by *note timefmt::), 2.45]
      4   x = date        y = axis           [31. 12. 1999, 2.45]
      5   x = time        y = axis           [23:59, 2.45]
      6   x = date time   y = axis           [31. 12. 1999 23:59, 2.45]
      7   format from *note mouseformat::, e.g. "mouse x,y = 1.23,     2.450"


File: gnuplot.info,  Node: scrolling,  Next: X11_mouse,  Prev: mouseformat,  Up: mouse

3.25.40.3 scrolling
...................

X and Y axis scaling in both 2D and 3D graphs can be adjusted using the
mouse wheel.  <wheel-up> scrolls up (increases both YMIN and YMAX by ten
percent of the Y range, and increases both Y2MIN and Y2MAX likewise),
and <wheel down> scrolls down.  <shift-wheel-up> scrolls left
(decreases both XMIN and XMAX, and both X2MIN and X2MAX), and
<shift-wheel-down> scrolls right.  <control-wheel-up> zooms in toward
the center of the plot, and <control-wheel-down> zooms out.
<shift-control-wheel-up> zooms in along the X and X2 axes only, and
<shift-control-wheel-down> zooms out along the X and X2 axes only.


File: gnuplot.info,  Node: X11_mouse,  Next: zoom,  Prev: scrolling,  Up: mouse

3.25.40.4 X11 mouse
...................

If multiple X11 plot windows have been opened using the `set term x11
<n>` terminal option, then only the current plot window supports the
entire range of mouse commands and hotkeys.  The other windows will,
however, continue to display mouse coordinates at the lower left.


File: gnuplot.info,  Node: zoom,  Prev: X11_mouse,  Up: mouse

3.25.40.5 zoom
..............

Zooming is usually accomplished by holding down the left mouse button
and dragging the mouse to delineate a zoom region.  Some platforms may
require using a different mouse button.  The original plot can be
restored by typing the 'u' hotkey in the plot window.  The hotkeys 'p'
and 'n' step back and forth through a history of zoom operations.

   The option `zoomcoordinates` determines if the coordinates of the
zoom box are drawn at the edges while zooming. This is on by default.

   If the option `zoomjump` is on, the mouse pointer will be
automatically offset a small distance after starting a zoom region with
button 3. This can be useful to avoid a tiny (or even empty) zoom
region. `zoomjump` is off by default.


File: gnuplot.info,  Node: multiplot,  Next: mx2tics,  Prev: mouse,  Up: set-show

3.25.41 multiplot
-----------------

The command *note multiplot:: places `gnuplot` in the multiplot mode,
in which several plots are placed on the same page, window, or screen.

   Syntax:
           set multiplot { layout <rows>,<cols>
                           {rowsfirst|columnsfirst} {downwards|upwards}
                           {title <page title>}
                           {scale <xscale>{,<yscale>}} {offset <xoff>{,<yoff>}}
                         }
           unset multiplot

   For some terminals, no plot is displayed until the command *note
multiplot:: is given, which causes the entire page to be drawn and then
returns gnuplot to its normal single-plot mode.  For other terminals,
each separate `plot` command produces an updated display, either by
redrawing all previous ones and the newly added plot, or by just adding
the new plot to the existing display.

   The area to be used by the next plot is not erased before doing the
new plot.  The *note clear:: command can be used to do this if wanted,
as is typically the case for "inset" plots.

   Any labels or arrows that have been defined will be drawn for each
plot according to the current size and origin (unless their coordinates
are defined in the `screen` system).  Just about everything else that
can be `set` is applied to each plot, too.  If you want something to
appear only once on the page, for instance a single time stamp, you'll
need to put a `set time`/`unset time` pair around one of the `plot`,
`splot` or *note replot:: commands within the *note multiplot::/*note
multiplot:: block.

   The multiplot title is separate from the individual plot titles, if
any.  Space is reserved for it at the top of the page, spanning the
full width of the canvas.

   The commands *note origin:: and *note size:: must be used to
correctly position each plot if no layout is specified or if fine
tuning is desired.  See *note origin:: and *note size:: for details of
their usage.

   Example:
           set multiplot
           set size 0.4,0.4
           set origin 0.1,0.1
           plot sin(x)
           set size 0.2,0.2
           set origin 0.5,0.5
           plot cos(x)
           unset multiplot

   This displays a plot of cos(x) stacked above a plot of sin(x).

   *note size:: and *note origin:: refer to the entire plotting area
used for each plot.  Please also see *note size::.  If you want to have
the axes themselves line up, you can guarantee that the margins are the
same size with the *note margin:: commands.  See *note margin:: for
their use.  Note that the margin settings are absolute, in character
units, so the appearance of the graph in the remaining space will
depend on the screen size of the display device, e.g., perhaps quite
different on a video display and a printer.

   With the `layout` option you can generate simple multiplots without
having to give the *note size:: and *note origin:: commands before each
plot:  Those are generated automatically, but can be overridden at any
time.  With `layout` the display will be divided by a grid with <rows>
rows and <cols> columns.  This grid is filled rows first or columns
first depending on whether the corresponding option is given in the
multiplot command.  The stack of plots can grow `downwards` or
`upwards`.  Default is `rowsfirst` and `downwards`.

   Each plot can be scaled by `scale` and shifted with `offset`; if the
y-values for scale or offset are omitted, the x-value will be used.
*note multiplot:: will turn off the automatic layout and restore the
values of *note size:: and *note origin:: as they were before `set
multiplot layout`.

   Example:
           set size 1,1
           set origin 0,0
           set multiplot layout 3,2 columnsfirst scale 1.1,0.9
           [ up to 6 plot commands here ]
           unset multiplot

   The above example will produce 6 plots in 2 columns filled top to
bottom, left to right.  Each plot will have a horizontal size of 1.1/2
and a vertical size of 0.9/3.

   See also multiplot demo (multiplt.dem)
(http://www.gnuplot.info/demo/multiplt.html)


File: gnuplot.info,  Node: mx2tics,  Next: mxtics,  Prev: multiplot,  Up: set-show

3.25.42 mx2tics
---------------

Minor tic marks along the x2 (top) axis are controlled by *note
mx2tics::.  Please see *note mxtics::.


File: gnuplot.info,  Node: mxtics,  Next: my2tics,  Prev: mx2tics,  Up: set-show

3.25.43 mxtics
--------------

Minor tic marks along the x axis are controlled by *note mxtics::.
They can be turned off with *note mxtics::.  Similar commands control
minor tics along the other axes.

   Syntax:
           set mxtics {<freq> | default}
           unset mxtics
           show mxtics

   The same syntax applies to *note mytics::, *note mztics::, *note
mx2tics::, *note my2tics:: and `mcbtics`.

   <freq> is the number of sub-intervals (NOT the number of minor tics)
between major tics (the default for a linear axis is either two or five
depending on the major tics, so there are one or four minor tics
between major tics). Selecting `default` will return the number of minor
ticks to its default value.

   If the axis is logarithmic, the number of sub-intervals will be set
to a reasonable number by default (based upon the length of a decade).
This will be overridden if <freq> is given.  However the usual minor
tics (2, 3, ..., 8, 9 between 1 and 10, for example) are obtained by
setting <freq> to 10, even though there are but nine sub-intervals.

   To set minor tics at arbitrary positions, use the ("<label>" <pos>
<level>, ...) form of `set {x|x2|y|y2|z}tics` with <label> empty and
<level> set to 1.

   The `set m{x|x2|y|y2|z}tics` commands work only when there are
uniformly spaced major tics.  If all major tics were placed explicitly
by `set {x|x2|y|y2|z}tics`, then minor tic commands are ignored.
Implicit major tics and explicit minor tics can be combined using `set
{x|x2|y|y2|z}tics` and `set {x|x2|y|y2|z}tics add`.

   Examples:
           set xtics 0, 5, 10
           set xtics add (7.5)
           set mxtics 5

   Major tics at 0,5,7.5,10, minor tics at 1,2,3,4,6,7,8,9
           set logscale y
           set ytics format ""
           set ytics 1e-6, 10, 1
           set ytics add ("1" 1, ".1" 0.1, ".01" 0.01, "10^-3" 0.001, \
                          "10^-4" 0.0001)
           set mytics 10

   Major tics with special formatting, minor tics at log positions

   By default, minor tics are off for linear axes and on for
logarithmic axes.  They inherit the settings for `axis|border` and
`{no}mirror` specified for the major tics.  Please see `set xtics` for
information about these.


File: gnuplot.info,  Node: my2tics,  Next: mytics,  Prev: mxtics,  Up: set-show

3.25.44 my2tics
---------------

Minor tic marks along the y2 (right-hand) axis are controlled by *note
my2tics::.  Please see *note mxtics::.


File: gnuplot.info,  Node: mytics,  Next: mztics,  Prev: my2tics,  Up: set-show

3.25.45 mytics
--------------

Minor tic marks along the y axis are controlled by *note mytics::.
Please see *note mxtics::.


File: gnuplot.info,  Node: mztics,  Next: object,  Prev: mytics,  Up: set-show

3.25.46 mztics
--------------

Minor tic marks along the z axis are controlled by *note mztics::.
Please see *note mxtics::.


File: gnuplot.info,  Node: object,  Next: offsets,  Prev: mztics,  Up: set-show

3.25.47 object
--------------

The *note object:: command defines a single object which will appear in
all subsequent 2D plots. You may define as many objects as you like.
Currently the supported object types are *note rectangle::, `circle`,
`ellipse`, and *note polygon::.  Rectangles inherit a default set of
style properties (fill, color, border) from those set by the command
*note rectangle::, but each object can also be given individual style
properties. Circles, ellipses, and polygons  inherit the fill style
from `set style fill`.

   Syntax:
         set object <index>
             <object-type> <object-properties>
             {front|back|behind} {fc|fillcolor <colorspec>} {fs <fillstyle>}
             {default} {lw|linewidth <width>}

   <object-type> is either *note rectangle::, `ellipse`, `circle`, or
*note polygon::.  Each object type has its own set of characteristic
properties.

   Setting `front` will draw the object in front of all plot elements,
but behind any labels that are also marked `front`. Setting `back` will
place the object behind all plot curves and labels. Setting `behind`
will place the object behind everything including the axes and `back`
rectangles, thus
         set object rectangle from screen 0,0 to screen 1,1 behind

   can be used to provide a colored background for the entire graph or
page.

   The fill color of the object is taken from the <colorspec>.
`fillcolor` may be abbreviated `fc`.  The fill style is taken from
<fillstyle>.  See *note colorspec:: and `fillstyle`.  If the keyword
`default` is given, these properties are inherited from the default
settings at the time a plot is drawn. See *note rectangle::.

* Menu:

* rectangle::
* ellipse::
* circle::
* polygon::


File: gnuplot.info,  Node: rectangle,  Next: ellipse,  Prev: object,  Up: object

3.25.47.1 rectangle
...................

Syntax:
         set object <index> rectangle
             {from <position> {to|rto} <position> |
              center <position> size <w>,<h> |
              at <position> size <w>,<h>}

   The position of the rectangle may be specified by giving the
position of two diagonal corners (bottom left and top right) or by
giving the position of the center followed by the width and the height.
In either case the positions may be given in axis, graph, or screen
coordinates. See `coordinates`.  The options `at` and `center` are
synonyms.

   Examples:
         # Force the entire area enclosed by the axes to have background color cyan
         set object 1 rect from graph 0, graph 0 to graph 1, graph 1 back
         set object 1 rect fc rgb "cyan" fillstyle solid 1.0

         # Position a red square with lower left at 0,0 and upper right at 2,3
         set object 2 rect from 0,0 to 2,3 fc lt 1

         # Position an empty rectangle (no fill) with a blue border
         set object 3 rect from 0,0 to 2,3 fs empty border rgb "blue"

         # Return fill and color to the default style but leave vertices unchanged
         set object 2 rect default

   Rectangle corners specified in screen coordinates may extend beyond
the edge of the current graph. Otherwise the rectangle is clipped to
fit in the graph.


File: gnuplot.info,  Node: ellipse,  Next: circle,  Prev: rectangle,  Up: object

3.25.47.2 ellipse
.................

Syntax:
         set object <index> ellipse {at|center} <position> size <w>,<h>
             {angle <orientation>} {units xy|xx|yy}
             {<other-object-properties>}

   The position of the ellipse is specified by giving the center
followed by the width and the height (actually the major and minor
axes). The keywords `at` and `center` are synonyms.  The center
position may be given in axis, graph, or screen coordinates. See
`coordinates`. The major and minor axis lengths must be given in axis
coordinates.  The orientation of the ellipse is specified by the angle
between the horizontal axis and the major diameter of the ellipse.  If
no angle is given, the default ellipse orientation will be used instead
(see `set style ellipse`).  The `units` keyword controls the scaling of
the axes of the ellipse. `units xy` means that the major axis is
interpreted in terms of units along the x axis, while the minor axis in
that of the y axis. `units xx` means that both axes of the ellipses are
scaled in the units of the x axis, while `units yy` means that both
axes are in units of the y axis.  The default is `xy` or whatever `set
style ellipse units` was set to.

   NB: If the x and y axis scales are not equal, (e.g. `units xy` is in
effect) then the major/minor axis ratio will no longer be correct after
rotation.

   Note that `set object ellipse size <2r>,<2r>` does not in general
produce the same result as `set object circle <r>`.  The circle radius
is always interpreted in terms of units along the x axis, and will
always produce a circle even if the x and y axis scales are different
and even if the aspect ratio of your plot is not 1.  If `units` is set
to `xy`, then 'set object ellipse' interprets the first <2r> in terms
of x axis units and the second <2r> in terms of y axis units. This will
only produce a circle if the x and y axis scales are identical and the
plot aspect ratio is 1.  On the other hand, if `units` is set to `xx`
or `yy`, then the diameters specified in the 'set object' command will
be interpreted in the same units, so the ellipse will have the correct
aspect ratio, and it will maintain its aspect ratio even if the plot is
resized.


File: gnuplot.info,  Node: circle,  Next: polygon,  Prev: ellipse,  Up: object

3.25.47.3 circle
................

Syntax:
         set object <index> circle {at|center} <position> size <radius>
             {arc [<begin>:<end>]}
             {<other-object-properties>}

   The position of the circle is specified by giving the position of
the center center followed by the radius.  The keywords `at` and
`center` are synonyms.  The position and radius may be given in x-axis,
graph, or canvas coordinates. See `coordinates`. In all cases the
radius is calculated relative to the horizontal scale of the axis,
graph, or canvas.  Any disparity between the horizontal and vertical
scaling will be corrected for so that the result is always a circle.

   By default a full circle is drawn. The optional qualifier `arc`
specifies a starting angle and ending angle, in degrees, for one arc of
the circle.  The arc is always drawn counterclockwise.


File: gnuplot.info,  Node: polygon,  Prev: circle,  Up: object

3.25.47.4 polygon
.................

Syntax:
         set object <index> polygon
             from <position> to <position> ... {to <position>}

   or
             from <position> rto <position> ... {rto <position>}

   The position of the polygon may be specified by giving the position
of a sequence of vertices. These may be given in axis, graph, or screen
coordinates.  If relative coordinates are used (rto) then the
coordinate type must match that of the previous vertex.  See
`coordinates`.

   Example:
         set object 1 polygon from 0,0 to 1,1 to 2,0
         set object 1 fc rgb "cyan" fillstyle solid 1.0 border lt -1


File: gnuplot.info,  Node: offsets,  Next: origin,  Prev: object,  Up: set-show

3.25.48 offsets
---------------

Offsets provide a mechanism to put an empty boundary around the data
inside an autoscaled graph.  The offsets only affect the x1 and y1
axes, and only in 2D `plot` commands.

   Syntax:
           set offsets <left>, <right>, <top>, <bottom>
           unset offsets
           show offsets

   Each offset may be a constant or an expression.  Each defaults to 0.
By default, the left and right offsets are given in units of the first
x axis, the top and bottom offsets in units of the first y axis.
Alternatively, you may specify the offsets as a fraction of the total
axis range by using the keyword "graph".  A positive offset expands the
axis range in the specified direction, e.g., a positive bottom offset
makes ymin more negative.  Negative offsets, while permitted, can have
unexpected interactions with autoscaling and clipping.  To prevent the
auto-scaling from further adjusting your axis ranges, it is useful to
also specify "set auto fix".

   Example:
           set auto fix
           set offsets graph 0.05, 0, 2, 2
           plot sin(x)

   This graph of sin(x) will have a y range [-3:3] because the function
will be autoscaled to [-1:1] and the vertical offsets are each two.
The x range will be [-11:10] because the default is [-10:10] and it has
been expanded to the left by 0.05 of that total range.


File: gnuplot.info,  Node: origin,  Next: output,  Prev: offsets,  Up: set-show

3.25.49 origin
--------------

The *note origin:: command is used to specify the origin of a plotting
surface (i.e., the graph and its margins) on the screen.  The
coordinates are given in the `screen` coordinate system (see
`coordinates` for information about this system).

   Syntax:
           set origin <x-origin>,<y-origin>


File: gnuplot.info,  Node: output,  Next: parametric_,  Prev: origin,  Up: set-show

3.25.50 output
--------------

By default, screens are displayed to the standard output. The *note
output:: command redirects the display to the specified file or device.

   Syntax:
           set output {"<filename>"}
           show output

   The filename must be enclosed in quotes.  If the filename is
omitted, any output file opened by a previous invocation of *note
output:: will be closed and new output will be sent to STDOUT.  (If you
give the command `set output "STDOUT"`, your output may be sent to a
file named "STDOUT"!  ["May be", not "will be", because some terminals,
like `x11` or `wxt`, ignore *note output::.])

   When both *note terminal:: and *note output:: are used together, it
is safest to give *note terminal:: first, because some terminals set a
flag which is needed in some operating systems.  This would be the
case, for example, if the operating system needs to know whether or not
a file is to be formatted in order to open it properly.

   On machines with popen functions (Unix), output can be piped through
a shell command if the first non-whitespace character of the filename
is '|'.  For instance,

           set output "|lpr -Plaser filename"
           set output "|lp -dlaser filename"

   On MSDOS machines, `set output "PRN"` will direct the output to the
default printer.  On VMS, output can be sent directly to any spooled
device.  It is also possible to send the output to DECnet transparent
tasks, which allows some flexibility.


File: gnuplot.info,  Node: parametric_,  Next: plot_,  Prev: output,  Up: set-show

3.25.51 parametric
------------------

The `set parametric` command changes the meaning of `plot` (`splot`)
from normal functions to parametric functions.  The command `unset
parametric` restores the plotting style to normal, single-valued
expression plotting.

   Syntax:
           set parametric
           unset parametric
           show parametric

   For 2D plotting, a parametric function is determined by a pair of
parametric functions operating on a parameter.  An example of a 2D
parametric function would be `plot sin(t),cos(t)`, which draws a circle
(if the aspect ratio is set correctly--see *note size::).  `gnuplot`
will display an error message if both functions are not provided for a
parametric `plot`.

   For 3D plotting, the surface is described as x=f(u,v), y=g(u,v),
z=h(u,v).  Therefore a triplet of functions is required.  An example of
a 3D parametric function would be `cos(u)*cos(v),cos(u)*sin(v),sin(u)`,
which draws a sphere.  `gnuplot` will display an error message if all
three functions are not provided for a parametric `splot`.

   The total set of possible plots is a superset of the simple f(x)
style plots, since the two functions can describe the x and y values to
be computed separately.  In fact, plots of the type t,f(t) are
equivalent to those produced with f(x) because the x values are
computed using the identity function.  Similarly, 3D plots of the type
u,v,f(u,v) are equivalent to f(x,y).

   Note that the order the parametric functions are specified is
xfunction, yfunction (and zfunction) and that each operates over the
common parametric domain.

   Also, the `set parametric` function implies a new range of values.
Whereas the normal f(x) and f(x,y) style plotting assume an xrange and
yrange (and zrange), the parametric mode additionally specifies a
trange, urange, and vrange.  These ranges may be set directly with
*note trange::, *note urange::, and *note vrange::, or by specifying
the range on the `plot` or `splot` commands.  Currently the default
range for these parametric variables is [-5:5].  Setting the ranges to
something more meaningful is expected.


File: gnuplot.info,  Node: plot_,  Next: pm3d,  Prev: parametric_,  Up: set-show

3.25.52 plot
------------

The `show plot` command shows the current plotting command as it results
from the last `plot` and/or `splot` and possible subsequent *note
replot:: commands.

   In addition, the `show plot add2history` command adds this current
plot command into the `history`. It is useful if you have used *note
replot:: to add more curves to the current plot and you want to edit
the whole command now.


File: gnuplot.info,  Node: pm3d,  Next: palette,  Prev: plot_,  Up: set-show

3.25.53 pm3d
------------

pm3d is an `splot` style for drawing palette-mapped 3d and 4d data as
color/gray maps and surfaces.  It uses an algorithm that allows plotting
gridded as well as non-gridded data without preprocessing, even when
the data scans do not have the same number of points.

   Syntax (the options can be given in any order):
           set pm3d {
                      { at <position> }
                      { interpolate <steps/points in scan, between scans> }
                      { scansautomatic | scansforward | scansbackward | depthorder }
                      { flush { begin | center | end } }
                      { ftriangles | noftriangles }
                      { clip1in | clip4in }
                      { corners2color { mean|geomean|median|min|max|c1|c2|c3|c4 } }
                      { hidden3d {<linestyle>} | nohidden3d }
                      { implicit | explicit }
                      { map }
                    }
           show pm3d
           unset pm3d

   A pm3d color surface is drawn if the splot command specifies *note
pm3d::, if the data or function *note style:: is set to pm3d globally,
or if the pm3d mode is `set pm3d implicit`.  In the latter two cases,
the pm3d surface is draw in addition to the mesh produced by the style
specified in the plot command. E.g.
           splot 'fred.dat' with lines, 'lola.dat' with lines

   would draw both a mesh of lines and a pm3d surface for each data set.
If the option `explicit` is on (or `implicit` is off) only plots
specified by the *note pm3d:: attribute are plotted with a pm3d
surface, e.g.:
           splot 'fred.dat' with lines, 'lola.dat' with pm3d

   would plot 'fred.dat' with lines (only) and 'lola.dat' with a pm3d
surface.

   On gnuplot start-up, the mode is `explicit`. For historical and
compatibility reasons, the commands `set pm3d;` (i.e. no options) and
`set pm3d at X ...` (i.e.  `at` is the first option) change the mode to
`implicit`.  The command `set pm3d;` sets other options to their
default state.

   If you set the default data or function style to *note pm3d::, e.g.:
           set style data pm3d

   then the options `implicit` and `explicit` have no effect.

   Note that when plotting several plots, they are plotted in the order
given on the command line. This can be of interest especially for
filled surfaces which can overwrite and therefore hide part of earlier
plots.

   The pm3d coloring can be drawn at any or all of three different
positions, `top`, `bottom`, or *note surface::. See *note position::.
The following command draws three color surfaces at different altitudes:
           set border 4095
           set pm3d at s
           splot 10*x with pm3d at b, x*x-y*y, x*x+y*y with pm3d at t

   See also help for *note palette::, *note cbrange::, `set colorbox`,
and definitely the demo file `demo/pm3d.dem`.

* Menu:

* algorithm::
* position::
* scanorder::
* clipping::
* color_assignment::
* hidden3d_::
* interpolate::
* deprecated_options::


File: gnuplot.info,  Node: algorithm,  Next: position,  Prev: pm3d,  Up: pm3d

3.25.53.1 algorithm
...................

Let us first describe how a map/surface is drawn.  The input data come
from an evaluated function or from an `splot data file`.  Each surface
consists of a sequence of separate scans (isolines).  The pm3d
algorithm fills the region between two neighbouring points in one scan
with another two points in the next scan by a gray (or color) according
to z-values (or according to an additional 'color' column, see help for
*note using::) of these 4 corners; by default the 4 corner values are
averaged, but this can be changed by the option `corners2color`.  In
order to get a reasonable surface, the neighbouring scans should not
cross and the number of points in the neighbouring scans should not
differ too much; of course, the best plot is with scans having same
number of points.  There are no other requirements (e.g. the data need
not be gridded).  Another advantage is that the pm3d algorithm does not
draw anything outside of the input (measured or calculated) region.

   Surface coloring works with the following input data:

   1. splot of function or of data file with one or three data columns:
The gray/color scale is obtained by mapping the averaged (or
`corners2color`) z-coordinate of the four corners of the
above-specified quadrangle into the range [min_color_z,max_color_z] of
*note zrange:: or *note cbrange:: providing a gray value in the range
[0:1].  This value can be used directly as the gray for gray maps.  The
normalized gray value can be further mapped into a color--see *note
palette:: for the complete description.

   2. splot of data file with two or four data columns: The gray/color
value is obtained by using the last-column coordinate instead of the
z-value, thus allowing the color and the z-coordinate be mutually
independent.  This can be used for 4d data drawing.

   Other notes:

   1. The term 'scan' referenced above is used more among physicists
than the term 'iso_curve' referenced in gnuplot documentation and
sources.  You measure maps recorded one scan after another scan, that's
why.

   2. The 'gray' or 'color' scale is a linear mapping of a continuous
variable onto a smoothly varying palette of colors. The mapping is
shown in a rectangle next to the main plot. This documentation refers
to this as a "colorbox", and refers to the indexing variable as lying
on the colorbox axis.  See `set colorbox`, *note cbrange::.

   3. To use pm3d coloring to generate a two-dimensional plot rather
than a 3D surface, use `set view map` or `set pm3d map`.


File: gnuplot.info,  Node: position,  Next: scanorder,  Prev: algorithm,  Up: pm3d

3.25.53.2 position
..................

Color surface can be drawn at the base or top (then it is a gray/color
planar map) or at z-coordinates of surface points (gray/color surface).
This is defined by the `at` option with a string of up to 6
combinations of `b`, `t` and `s`. For instance, `at b` plots at bottom
only, `at st` plots firstly surface and then top map, while `at bstbst`
will never by seriously used.

   Colored quadrangles are plotted one after another.  When plotting
surfaces (`at s`), the later quadrangles overlap (overdraw) the
previous ones.  (Gnuplot is not virtual reality tool to calculate
intersections of filled polygon meshes.)  You may try to switch between
`scansforward` and `scansbackward` to force the first scan of the data
to be plotted first or last.  The default is `scansautomatic` where
gnuplot makes a guess about scans order.  On the other hand, the
`depthorder` option completely reorders the quadrangles. The rendering
is performed after a depth sorting, which allows to visualize even
complicated surfaces; see `pm3d depthorder` for more details.


File: gnuplot.info,  Node: scanorder,  Next: clipping,  Prev: position,  Up: pm3d

3.25.53.3 scanorder
...................

By default the quadrangles making up a pm3d solid surface are rendered
in the order they are encountered along the surface grid points.  This
order may be controlled by the options
`scansautomatic`|`scansforward`|`scansbackward`.  These scan options
are not in general compatible with hidden-surface removal.

   If two successive scans do not have same number of points, then it
has to be decided whether to start taking points for quadrangles from
the beginning of both scans (`flush begin`), from their ends (`flush
end`) or to center them (`flush center`).  Note, that `flush
(center|end)` are incompatible with `scansautomatic`: if you specify
`flush center` or `flush end` and `scansautomatic` is set, it is
silently switched to `scansforward`.

   If two subsequent scans do not have the same number of points, the
option `ftriangles` specifies whether color triangles are drawn at the
scan tail(s) where there are not enough points in either of the scan.
This can be used to draw a smooth map boundary.

   Gnuplot does not do true hidden surface removal for solid surfaces,
but often it is sufficient to render the component quadrangles in order
from furthest to closest.  This mode may be selected using the options
           set pm3d depthorder hidden3d

   The `depthorder` option orders the solid quadrangles; the *note
hidden3d:: option similarly orders the bounding lines (if drawn).  Note
that the global option *note hidden3d:: does not affect pm3d surfaces.


File: gnuplot.info,  Node: clipping,  Next: color_assignment,  Prev: scanorder,  Up: pm3d

3.25.53.4 clipping
..................

Clipping with respect to x, y coordinates of quadrangles can be done in
two ways.  `clip1in`: all 4 points of each quadrangle must be defined
and at least 1 point of the quadrangle must lie in the x and y ranges.
`clip4in`: all 4 points of each quadrangle must lie in the x and y
ranges.


File: gnuplot.info,  Node: color_assignment,  Next: hidden3d_,  Prev: clipping,  Up: pm3d

3.25.53.5 color_assignment
..........................

`3 columns of data (x,y,z)`:

   The coloring setup as well as the color box drawing are determined by
*note palette::.  There can be only one palette for the current plot.
Drawing of several surfaces with different palettes can be achieved by
*note multiplot:: with fixed *note origin:: and *note size::; don't
forget to use `set palette maxcolors` when your terminal is running out
of available colors.

   There is a single gray/color value associated to each drawn pm3d
quadrangle (no smooth color change among vertices).  The value is
calculated from z-coordinates from the surrounding corners according to
`corners2color <option>`.  The options 'mean' (default), 'geomean' and
'median' produce various kinds of surface color smoothing, while
options 'min' and 'max' choose minimal or maximal value, respectively.
This may not be desired for pixel images or for maps with sharp and
intense peaks, in which case the options 'c1', 'c2', 'c3' or 'c4' can
be used instead to assign the quadrangle color based on the
z-coordinate of only one corner.  Some experimentation may be needed to
determine which corner corresponds to 'c1', as the orientation depends
on the drawing direction.  Because the pm3d algorithm does not extend
the colored surface outside the range of the input data points, the
'c<j>' coloring options will result in pixels along two edges of the
grid not contributing to the color of any quadrangle.  For example,
applying the pm3d algorithm to the 4x4 grid of data points in script
`demo/pm3d.dem` (please have a look) produces only (4-1)x(4-1)=9
colored rectangles.

   `4 columns of data (x,y,z,color)`:

   If a fourth column of data is provided, it is normally interpreted
as a separate palette-mapped gray value. The coloring of individual
quadrangles works as above, except that the color value is distinct
from the z value.  As a separate coloring option, the fourth data
column may provide instead an RGB color. See `rgbcolor variable`. In
this case the plotting command must be

           splot ... using 1:2:3:4 with pm3d lc rgb variable

   Another drawing algorithm, which would draw quadrangles around a
given node by taking corners from averaged (x,y)-coordinates of its
surrounding 4 nodes while using node's color, could be implemented in
the future. This is already done for drawing images (2D grids) via
`image` and *note rgbimage:: styles.

   Notice that ranges of z-values and color-values for surfaces are
adjustable independently by *note zrange::, *note cbrange::, as well as
`set log` for z or cb.  Maps can be adjusted by the cb-axis only; see
also `set view map` and `set colorbox`.


File: gnuplot.info,  Node: hidden3d_,  Next: interpolate,  Prev: color_assignment,  Up: pm3d

3.25.53.6 hidden3d
..................

The option *note hidden3d:: draws the bounding lines of each quadrangle
at the same time that the quadrangle itself is drawn. Normally it is
used in conjunction with the `depthorder` option to achieve an
approximation to true hidden line removal.  This is far more efficient
than using the command *note hidden3d::.  The command takes an optional
linestyle controlling the appearance of the bounding lines.  If the
linestyle parameter is negative, or omitted, then the line properties
given in the plot command are used.  Example of recommended usage:

           set pm3d at s hidden3d depthorder
           unset hidden3d
           unset surf
           splot x*x+y*y linecolor rgb "black" linewidth 0.5


File: gnuplot.info,  Node: interpolate,  Next: deprecated_options,  Prev: hidden3d_,  Up: pm3d

3.25.53.7 interpolate
.....................

The option `interpolate m,n` will interpolate grid points into a finer
mesh, and color each quadrangle appropriately.  For data files, this
will smoothen the color surface, and enhance spikes in a color surface.
For functions, interpolation makes little sense, except to trade off
precision for memory.  It would usually make more sense to use *note
samples:: and *note isosamples:: when working with functions. For
positive m and n, each quadrangle or triangle is interpolated m-times
and n-times in the respective direction.  For negative m and n, the
interpolation frequency is chosen so that there will be at least |m|
and |n| points drawn; you can consider this as a special gridding
function.  Zeros, i.e. `interpolate 0,0`, will automatically choose an
optimal number of interpolated surface points.


File: gnuplot.info,  Node: deprecated_options,  Prev: interpolate,  Up: pm3d

3.25.53.8 deprecated_options
............................

There used to be an option {transparent|solid} to this command.  Now
you get the same effect from `set grid {front|layerdefault}`,
respectively.

   The command `set pm3d map` is equivalent to `set pm3d at b`; `set
view map`; *note pm3d::; *note pm3d::;.  It is used for backwards
compatibility, when `set view map` was not available.  Take care that
you properly use *note zrange:: and *note cbrange:: for input data point
filtering and color range scaling, respectively; and also `set
(no)surface` seems to have a (side?) effect.


File: gnuplot.info,  Node: palette,  Next: pointintervalbox,  Prev: pm3d,  Up: set-show

3.25.54 palette
---------------

Palette is a color storage for use by *note pm3d::, filled color
contours or polygons, color histograms, color gradient background, and
whatever it is or it will be implemented...  Here it stands for a
palette of smooth "continuous" colors or grays, but let's call it just
a palette.

   Color palettes require terminal entries for filled color polygons and
palettes of smooth colors, are currently available for terminals listed
in help for *note pm3d::. The range of color values are adjustable
independently by *note cbrange:: and `set log cb`. The whole color
palette is visualized in the `colorbox`.

   Syntax:
           set palette
           set palette {
                      { gray | color }
                      { gamma <gamma> }
                      {   rgbformulae <r>,<g>,<b>
                        | defined { ( <gray1> <color1> {, <grayN> <colorN>}... ) }
                        | file '<filename>' {datafile-modifiers}
                        | functions <R>,<G>,<B>
                      }
                      { cubehelix {start <val>} {cycles <val>} {saturation <val>} }
                      { model { RGB | HSV | CMY | YIQ | XYZ } }
                      { positive | negative }
                      { nops_allcF | ps_allcF }
                      { maxcolors <maxcolors> }
                    }
           show palette
           show palette palette <n> {{float | int}}
           show palette gradient
           show palette fit2rgbformulae
           show palette rgbformulae
           show colornames

   *note palette:: (i.e. without options) sets up the default values.
Otherwise, the options can be given in any order.  *note palette::
shows the current palette properties.

   `show palette gradient` displays the gradient defining the palette
(if appropriate).  *note rgbformulae:: prints the available fixed gray
-> color transformation formulae.  *note colornames:: prints the known
color names.

   `show palette palette <n>` prints to the screen or to the file given
by *note print:: a table of RGB triplets calculated for the current
palette settings and a palette having <n> discrete colors.  The default
wide table can be limited to 3 columns of r,g,b float values [0..1] or
integer values [0..255] by options float or int, respectively.  This
way, the current gnuplot color palette can be loaded into other imaging
applications, for example Octave.  Additionally to this textual list of
RGB table, you can use the *note palette:: command to plot the R,G,B
profiles for the current palette.

   The following options determine the coloring properties.

   Figure using this palette can be `gray` or `color`.  For instance,
in *note pm3d:: color surfaces the gray of each small spot is obtained
by mapping the averaged z-coordinate of the 4 corners of surface
quadrangles into the range [min_z,max_z] providing range of grays
[0:1]. This value can be used directly as the gray for gray maps. The
color map requires a transformation gray -> (R,G,B), i.e. a mapping
[0:1] -> ([0:1],[0:1],[0:1]).

   Basically two different types of mappings can be used:  Analytic
formulae to convert gray to color, or discrete mapping tables which are
interpolated.  *note rgbformulae:: and *note functions:: use analytic
formulae whereas *note defined:: and `palette file` use interpolated
tables.  *note rgbformulae:: reduces the size of postscript output to a
minimum.

   The command `show palette fit2rgbformulae` finds the best matching
*note rgbformulae:: for the current *note palette::. Naturally, it
makes sense to use it for non-rgbformulae palettes. This command can be
found useful mainly for external programs using the same rgbformulae
definition of palettes as gnuplot, like zimg (
http://zimg.sourceforge.net (http://zimg.sourceforge.net) ).

   `set palette gray` switches to a gray only palette. *note
rgbformulae::, *note defined::, `set palette file` and *note
functions:: switch to a color mapping. `set palette color` is an easy
way to switch back from the gray palette to the last color mapping.

   Automatic gamma correction via `set palette gamma <gamma>` can be
done for gray maps (`set palette gray`) and for the *note cubehelix::
color palette schemes.  Gamma = 1 produces a linear ramp of intensity.
See *note palette::.

   Many terminals support only discrete number of colors (e.g. 256
colors in gif).  After the default gnuplot linetype colors are
allocated, the rest of the available colors are by default reserved for
pm3d.  Thus a multiplot using multiple palettes could fail because the
first palette has used all the available color positions.  You can
mitigate this limitation by using `set palette maxcolors <N>` with a
reasonably small value of N.  This option causes N discrete colors to
be selected from a continuous palette sampled at equally spaced
intervals.  If you want unequal spacing of N discrete colors, use *note
defined:: instead of a single continuous palette.

   RGB color space might not be the most useful color space to work in.
For that reason you may change the color space with `model` to one of
`RGB`, `HSV`, `CMY`, `YIQ` and `XYZ`.  Using color names for *note
defined:: tables and a color space other than RGB will result in funny
colors.  All explanation have been written for RGB color space, so
please note, that `R` can be `H`, `C`, `Y`, or `X`, depending on the
actual color space (`G` and `B` accordingly).

   All values for all color spaces are limited to [0,1].

   RGB stands for Red, Green and Blue;  CMY stands for Cyan, Magenta
and Yellow; HSV stands for Hue, Saturation, and Value;  YIQ is the
color model used by the U.S. Commercial Color Television Broadcasting,
it is basically an RGB recoding with downward compatibility for black
and white television; XYZ are the three primary colors of the color
model defined by the 'Commission Internationale de l'Eclairage' (CIE).
For more information on color models see:
http://en.wikipedia.org/wiki/Color_space
(http://en.wikipedia.org/wiki/Color_space)

* Menu:

* rgbformulae::
* defined_::
* functions__::
* cubehelix::
* file::
* gamma_correction::
* postscript::


File: gnuplot.info,  Node: rgbformulae,  Next: defined_,  Prev: palette,  Up: palette

3.25.54.1 rgbformulae
.....................

For *note rgbformulae:: three suitable mapping functions have to be
chosen.  This is done via `rgbformulae <r>,<g>,<b>`.  The available
mapping functions are listed by *note rgbformulae::.  Default is
`7,5,15`, some other examples are `3,11,6`, `21,23,3` or `3,23,21`.
Negative numbers, like `3,-11,-6`, mean inverted color (i.e.  1-gray
passed into the formula, see also `positive` and `negative` options
below).

   Some nice schemes in RGB color space
        7,5,15   ... traditional pm3d (black-blue-red-yellow)
        3,11,6   ... green-red-violet
        23,28,3  ... ocean (green-blue-white); try also all other permutations
        21,22,23 ... hot (black-red-yellow-white)
        30,31,32 ... color printable on gray (black-blue-violet-yellow-white)
        33,13,10 ... rainbow (blue-green-yellow-red)
        34,35,36 ... AFM hot (black-red-yellow-white)

   A full color palette in HSV color space
        3,2,2    ... red-yellow-green-cyan-blue-magenta-red

   Please note that even if called *note rgbformulae:: the formulas
might actually determine the <H>,<S>,<V> or <X>,<Y>,<Z> or ... color
components as usual.

   Use `positive` and `negative` to invert the figure colors.

   Note that it is possible to find a set of the best matching
rgbformulae for any other color scheme by the command
        show palette fit2rgbformulae


File: gnuplot.info,  Node: defined_,  Next: functions__,  Prev: rgbformulae,  Up: palette

3.25.54.2 defined
.................

Gray-to-rgb mapping can be manually set by use of *note defined::: A
color gradient is defined and used to give the rgb values.  Such a
gradient is a piecewise linear mapping from gray values in [0,1] to the
RGB space [0,1]x[0,1]x[0,1].  You must specify the gray values and the
corresponding RGB values between which linear interpolation will be
done.

   Syntax:
           set palette  defined { ( <gray1> <color1> {, <grayN> <colorN>}... ) }

   <grayX> are gray values which are mapped to [0,1] and <colorX> are
the corresponding rgb colors.  The color can be specified in three
different ways:

          <color> :=  { <r> <g> <b> | '<color-name>' | '#rrggbb' }

   Either by three numbers (each in [0,1]) for red, green and blue,
separated by whitespace, or the name of the color in quotes or X style
color specifiers also in quotes.  You may freely mix the three types in
a gradient definition, but the named color "red" will be something
strange if RGB is not selected as color space.  Use *note colornames::
for a list of known color names.

   Please note, that even if written as <r>, this might actually be the
<H> component in HSV color space or <X> in CIE-XYZ space, or ...
depending on the selected color model.

   The <gray> values have to form an ascending sequence of real
numbers; the sequence will be automatically rescaled to [0,1].

   *note defined:: (without a gradient definition in braces) switches to
RGB color space and uses a preset full-spectrum color gradient.  Use
`show palette gradient` to display the gradient.

   Examples:

   To produce a gray palette (useless but instructive) use:
           set palette model RGB
           set palette defined ( 0 "black", 1 "white" )

   To produce a blue yellow red palette use (all equivalent):
           set palette defined ( 0 "blue", 1 "yellow", 2 "red" )
           set palette defined ( 0 0 0 1, 1 1 1 0, 2 1 0 0 )
           set palette defined ( 0 "#0000ff", 1 "#ffff00", 2 "#ff0000" )

   To produce some rainbow-like palette use:
           set palette defined ( 0 "blue", 3 "green", 6 "yellow", 10 "red" )

   Full color spectrum within HSV color space:
           set palette model HSV
           set palette defined ( 0 0 1 1, 1 1 1 1 )
           set palette defined ( 0 0 1 0, 1 0 1 1, 6 0.8333 1 1, 7 0.8333 0 1)

   Approximate the default palette used by MATLAB:
           set pal defined (1 '#00008f', 8 '#0000ff', 24 '#00ffff', \
                            40 '#ffff00', 56 '#ff0000', 64 '#800000')

   To produce a palette with only a few, equally-spaced colors:
           set palette model RGB maxcolors 4
           set palette defined ( 0 "yellow", 1 "red" )

   'Traffic light' palette (non-smooth color jumps at gray = 1/3 and
2/3).
           set palette model RGB
           set palette defined (0 "dark-green", 1 "green", \
                                1 "yellow",     2 "dark-yellow", \
                                2 "red",        3 "dark-red" )


File: gnuplot.info,  Node: functions__,  Next: cubehelix,  Prev: defined_,  Up: palette

3.25.54.3 functions
...................

Use `set palette functions <Rexpr>, <Gexpr>, <Bexpr>` to define three
formulae for the R(gray), G(gray) and B(gray) mapping.  The three
formulae may depend on the variable `gray` which will take values in
[0,1] and should also produce values in [0,1].  Please note that
<Rexpr> might be a formula for the H-value if HSV color space has been
chosen (same for all other formulae and color spaces).

   Examples:

   To produce a full color palette use:
           set palette model HSV functions gray, 1, 1

   A nice black to gold palette:
           set palette model XYZ functions gray**0.35, gray**0.5, gray**0.8

   A gamma-corrected black and white palette
           gamma = 2.2
           color(gray) = gray**(1./gamma)
           set palette model RGB functions color(gray), color(gray), color(gray)


File: gnuplot.info,  Node: cubehelix,  Next: file,  Prev: functions__,  Up: palette

3.25.54.4 cubehelix
...................

The "cubehelix" option defines a family of palettes in which color
(hue) varies along the standard color wheel while at the same time the
net intensity increases monotonically as the gray value goes from 0 to
1.
           D A Green (2011) http://arxiv.org/abs/1108.5083

   `start` defines the starting point along the color wheel in radians.
`cycles` defines how many color wheel cycles span the palette range.
Larger values of `saturation` produce more saturated color; saturation
> 1 may lead to clipping of the individual RGB components and to
intensity becoming non-monotonic. The palette is also affected by `set
palette gamma`.  The default values are
           set palette cubehelix start 0.5 cycles -1.5 saturation 1
           set palette gamma 1.5


File: gnuplot.info,  Node: file,  Next: gamma_correction,  Prev: cubehelix,  Up: palette

3.25.54.5 file
..............

`set palette file` is basically a `set palette defined (<gradient>)`
where <gradient> is read from a datafile.  Either 4 columns
(gray,R,G,B) or just three columns (R,G,B) have to be selected via the
*note using:: data file modifier.  In the three column case, the line
number will be used as gray.  The gray range is automatically rescaled
to [0,1].  The file is read as a normal data file, so all datafile
modifiers can be used.  Please note, that `R` might actually be e.g.
`H` if HSV color space is selected.

   As usual <filename> may be `'-'` which means that the data follow
the command inline and are terminated by a single `e` on a line of its
own.

   Use `show palette gradient` to display the gradient.

   Examples:

   Read in a palette of RGB triples each in range [0,255]:
           set palette file 'some-palette' using ($1/255):($2/255):($3/255)

   Equidistant rainbow (blue-green-yellow-red) palette:
           set palette model RGB file "-"
           0 0 1
           0 1 0
           1 1 0
           1 0 0
           e

   Binary palette files are supported as well, see *note general::.
Example: put 64 triplets of R,G,B doubles into file palette.bin and
load it by
           set palette file "palette.bin" binary record=64 using 1:2:3


File: gnuplot.info,  Node: gamma_correction,  Next: postscript,  Prev: file,  Up: palette

3.25.54.6 gamma correction
..........................

For gray mappings gamma correction can be turned on by `set palette
gamma <gamma>`.  <gamma> defaults to 1.5 which is quite suitable for
most terminals.

   The gamma correction is applied to the cubehelix color palette
family, but not to other palette coloring schemes. However, you may
easily implement gamma correction for explicit color functions.

   Example:
           set palette model RGB
           set palette functions gray**0.64, gray**0.67, gray**0.70

   To use gamma correction with interpolated gradients specify
intermediate gray values with appropriate colors.  Instead of

           set palette defined ( 0 0 0 0, 1 1 1 1 )

   use e.g.

           set palette defined ( 0 0 0 0, 0.5 .73 .73 .73, 1 1 1 1 )

   or even more intermediate points until the linear interpolation fits
the "gamma corrected" interpolation well enough.


File: gnuplot.info,  Node: postscript,  Prev: gamma_correction,  Up: palette

3.25.54.7 postscript
....................

In order to reduce the size of postscript files, the gray value and not
all three calculated r,g,b values are written to the file.  Therefore
the analytical formulae are coded directly in the postscript language
as a header just before the pm3d drawing, see /g and /cF definitions.
Usually, it makes sense to write therein definitions of only the 3
formulae used.  But for multiplot or any other reason you may want to
manually edit the transformations directly in the postscript file.
This is the default option `nops_allcF`.  Using the option `ps_allcF`
writes postscript definitions of all formulae.  This you may find
interesting if you want to edit the postscript file in order to have
different palettes for different surfaces in one graph.  Well, you can
achieve this functionality by *note multiplot:: with fixed *note
origin:: and *note size::.

   If pm3d map has been plotted from gridded or almost regular data
with an output to a postscript file, then it is possible to reduce the
size of this postscript file up to at about 50% by the enclosed awk
script `pm3dCompress.awk`.  This you may find  interesting if you
intend to keep the file for including it into your publication or
before downloading a very large file into a slow printer. Usage:
         awk -f pm3dCompress.awk thefile.ps >smallerfile.ps

   If pm3d map has been plotted from rectangular gridded data with an
output to a postscript file, then it is possible to reduce the file
size even more by the enclosed awk script `pm3dConvertToImage.awk`.
Usage:
         awk -f pm3dConvertToImage.awk <thefile.ps >smallerfile.ps

   You may manually change the postscript output from gray to color and
vice versa and change the definition of <maxcolors>.


File: gnuplot.info,  Node: pointintervalbox,  Next: pointsize,  Prev: palette,  Up: set-show

3.25.55 pointintervalbox
------------------------

The `pointinterval` property of line types is used in plot style *note
linespoints::.  A negative value of pointinterval, e.g. -N, means that
point symbols are drawn only for every Nth point, and that a box
(actually circle) behind each point symbol is blanked out by filling
with the background color.  The command *note pointintervalbox::
controls the radius of this blanked-out region.  It is a multiplier for
the default radius, which is equal to the point size.


File: gnuplot.info,  Node: pointsize,  Next: polar_,  Prev: pointintervalbox,  Up: set-show

3.25.56 pointsize
-----------------

The *note pointsize:: command scales the size of the points used in
plots.

   Syntax:
           set pointsize <multiplier>
           show pointsize

   The default is a multiplier of 1.0.  Larger pointsizes may be useful
to make points more visible in bitmapped graphics.

   The pointsize of a single plot may be changed on the `plot` command.
See *note with:: for details.

   Please note that the pointsize setting is not supported by all
terminal types.


File: gnuplot.info,  Node: polar_,  Next: print_,  Prev: pointsize,  Up: set-show

3.25.57 polar
-------------

The `set polar` command changes the meaning of the plot from rectangular
coordinates to polar coordinates.

   Syntax:
           set polar
           unset polar
           show polar

   In polar coordinates, the dummy variable (t) is an angle.  The
default range of t is [0:2*pi], or, if degree units have been selected,
to [0:360] (see *note angles::).

   The command `unset polar` changes the meaning of the plot back to
the default rectangular coordinate system.

   The `set polar` command is not supported for `splot`s.  See the
*note mapping:: command for similar functionality for `splot`s.

   While in polar coordinates the meaning of an expression in t is
really r = f(t), where t is an angle of rotation.  The trange controls
the domain (the angle) of the function. The r, x and y ranges control
the extent of the graph in the x and y directions.  Each of these
ranges, as well as the rrange, may be autoscaled or set explicitly.
For details, see *note rrange:: and *note xrange::.

   Example:
           set polar
           plot t*sin(t)
           set trange [-2*pi:2*pi]
           set rrange [0:3]
           plot t*sin(t)

   The first `plot` uses the default polar angular domain of 0 to 2*pi.
The radius and the size of the graph are scaled automatically.  The
second `plot` expands the domain, and restricts the size of the graph
to the area within 3 units of the origin.  This has the effect of
limiting x and y to [-3:3].

   You may want to `set size square` to have `gnuplot` try to make the
aspect ratio equal to unity, so that circles look circular.  See also
polar demos (polar.dem) (http://www.gnuplot.info/demo/polar.html) and
polar data plot (poldat.dem). (http://www.gnuplot.info/demo/poldat.html)


File: gnuplot.info,  Node: print_,  Next: psdir,  Prev: polar_,  Up: set-show

3.25.58 print
-------------

The *note print:: command redirects the output of the *note print::
command to a file.

   Syntax:
           set print
           set print "-"
           set print "<filename>"
           set print "<filename>" append
           set print "|<shell_command>"

   Without "<filename>", the output file is restored to <STDERR>.  The
<filename> "-" means <STDOUT>. The `append` flag causes the file to be
opened in append mode.  A <filename> starting with "|" is opened as a
pipe to the <shell_command> on platforms that support piping.


File: gnuplot.info,  Node: psdir,  Next: raxis,  Prev: print_,  Up: set-show

3.25.59 psdir
-------------

The `set psdir <directory>` command controls the search path used by the
postscript terminal to find prologue.ps and character encoding files.
You can use this mechanism to switch between different sets of
locally-customized prolog files.  The search order is
           1) The directory specified by *note psdir::, if any
           2) The directory specified by environmental variable GNUPLOT_PS_DIR
           3) A built-in header or one from the default system directory
           4) Directories set by *note loadpath::


File: gnuplot.info,  Node: raxis,  Next: rmargin,  Prev: psdir,  Up: set-show

3.25.60 raxis
-------------

The commands *note raxis:: and *note raxis:: toggle whether the polar
axis is drawn separately from grid lines and the x axis.  If the
minimum of the current rrange is non-zero (and not autoscaled), then a
white circle is drawn at the center of the polar plot to indicate that
the plot lines and axes do not reach 0.  The axis line is drawn using
the same line type as the plot border.  See `polar`, *note rrange::,
*note rtics::, `set grid`.


File: gnuplot.info,  Node: rmargin,  Next: rrange,  Prev: raxis,  Up: set-show

3.25.61 rmargin
---------------

The command *note rmargin:: sets the size of the right margin.  Please
see *note margin:: for details.


File: gnuplot.info,  Node: rrange,  Next: rtics,  Prev: rmargin,  Up: set-show

3.25.62 rrange
--------------

The *note rrange:: command sets the range of the radial coordinate for
a graph in polar mode.  This has the effect of setting both xrange and
yrange as well.  The resulting xrange and yrange are both [-(rmax-rmin)
: +(rmax-rmin)].  However if you later change the x or y range, for
example by zooming, this does not change rrange, so data points
continue to be clipped against rrange.  Autoscaling of rmin always
results in rmin = 0.


File: gnuplot.info,  Node: rtics,  Next: samples,  Prev: rrange,  Up: set-show

3.25.63 rtics
-------------

The *note rtics:: command places tics along the polar axis. These will
only be shown in polar plot mode.  The tics and labels are drawn to the
right of the origin. The `mirror` keyword causes them to be drawn also
to the left of the origin. See `polar`, and see `set xtics` for
discussion of other keywords.


File: gnuplot.info,  Node: samples,  Next: size,  Prev: rtics,  Up: set-show

3.25.64 samples
---------------

The sampling rate of functions, or for interpolating data, may be
changed by the *note samples:: command.

   Syntax:
           set samples <samples_1> {,<samples_2>}
           show samples

   By default, sampling is set to 100 points.  A higher sampling rate
will produce more accurate plots, but will take longer.  This parameter
has no effect on data file plotting unless one of the
interpolation/approximation options is used.  See *note smooth:: re 2D
data and *note cntrparam:: and *note dgrid3d:: re 3D data.

   When a 2D graph is being done, only the value of <samples_1> is
relevant.

   When a surface plot is being done without the removal of hidden
lines, the value of samples specifies the number of samples that are to
be evaluated for the isolines.  Each iso-v line will have <sample_1>
samples and each iso-u line will have <sample_2> samples.  If you only
specify <samples_1>, <samples_2> will be set to the same value as
<samples_1>.  See also *note isosamples::.


File: gnuplot.info,  Node: size,  Next: style,  Prev: samples,  Up: set-show

3.25.65 size
------------

Syntax:
           set size {{no}square | ratio <r> | noratio} {<xscale>,<yscale>}
           show size

   The <xscale> and <yscale> values are scale factors for the size of
the plot, which includes the graph, labels, and margins.

   Important note:
           In earlier versions of gnuplot, some terminal types used the values from
           *note size:: to control also the size of the output canvas; others did not.
           In version 4.6 almost all terminals now follow the following convention:

   `set term <terminal_type> size <XX>, <YY>` controls the size of the
output file, or `canvas`. Please see individual terminal documentation
for allowed values of the size parameters.  By default, the plot will
fill this canvas.

   `set size <XX>, <YY>` scales the plot itself relative to the size of
the canvas.  Scale values less than 1 will cause the plot to not fill
the entire canvas.  Scale values larger than 1 will cause only a
portion of the plot to fit on the canvas.  Please be aware that setting
scale values larger than 1 may cause problems on some terminal types.

   `ratio` causes `gnuplot` to try to create a graph with an aspect
ratio of <r> (the ratio of the y-axis length to the x-axis length)
within the portion of the plot specified by <xscale> and <yscale>.

   The meaning of a negative value for <r> is different.  If <r>=-1,
gnuplot tries to set the scales so that the unit has the same length on
both the x and y axes.  This is equivalent to `set view equal xy`.  See
`set view equal`.  If <r>=-2, the unit on y has twice the length of the
unit on x, and so on.

   The success of `gnuplot` in producing the requested aspect ratio
depends on the terminal selected.  The graph area will be the largest
rectangle of aspect ratio <r> that will fit into the specified portion
of the output (leaving adequate margins, of course).

   `square` is a synonym for `ratio 1`.

   Both `noratio` and `nosquare` return the graph to the default aspect
ratio of the terminal, but do not return <xscale> or <yscale> to their
default values (1.0).

   `ratio` and `square` have no effect on 3D plots, but do affect 3D
projections created using `set view map`.  See also `set view equal`,
which forces the x and y axes of a 3D onto the same scale.

   Examples:

   To set the size so that the plot fills the available canvas:
           set size 1,1

   To make the graph half size and square use:
           set size square 0.5,0.5

   To make the graph twice as high as wide use:
           set size ratio 2


File: gnuplot.info,  Node: style,  Next: surface,  Prev: size,  Up: set-show

3.25.66 style
-------------

Default plotting styles are chosen with the `set style data` and `set
style function` commands.  See *note with:: for information about how to
override the default plotting style for individual functions and data
sets.  See `plotting styles` for a complete list of styles.

   Syntax:
           set style function <style>
           set style data <style>
           show style function
           show style data

   Default styles for specific plotting elements may also be set.

   Syntax:
           set style arrow <n> <arrowstyle>
           set style fill <fillstyle>
           set style histogram <histogram style options>
           set style line <n> <linestyle>

   If `gnuplot` was built with the support of objects, then the
following options are also available:

   Syntax:
           set style rectangle <object options> <linestyle> <fillstyle>
           set style circle radius <size>
           set style ellipse size <size> units {xy|xx|yy}

* Menu:

* set_style_arrow::
* boxplot_::
* set_style_data::
* set_style_fill::
* set_style_function::
* set_style_increment::
* set_style_line::
* set_style_circle::
* set_style_rectangle::
* set_style_ellipse::


File: gnuplot.info,  Node: set_style_arrow,  Next: boxplot_,  Prev: style,  Up: style

3.25.66.1 set style arrow
.........................

Each terminal has a default set of arrow and point types, which can be
seen by using the command *note test::.  *note arrow:: defines a set of
arrow types and widths and point types and sizes so that you can refer
to them later by an index instead of repeating all the information at
each invocation.

   Syntax:
           set style arrow <index> default
           set style arrow <index> {nohead | head | heads}
                                   {size <length>,<angle>{,<backangle>}}
                                   {filled | empty | nofilled}
                                   {front | back}
                                   { {linestyle | ls <line_style>}
                                     | {linetype | lt <line_type>}
                                       {linewidth | lw <line_width} }
           unset style arrow
           show style arrow

   <index> is an integer that identifies the arrowstyle.

   If `default` is given all arrow style parameters are set to their
default values.

   If the linestyle <index> already exists, only the given parameters
are changed while all others are preserved.  If not, all undefined
values are set to the default values.

   Specifying `nohead` produces arrows drawn without a head--a line
segment.  This gives you yet another way to draw a line segment on the
plot.  By default, arrows have one head. Specifying `heads` draws arrow
heads on both ends of the line.

   Head size can be controlled by `size <length>,<angle>` or `size
<length>,<angle>,<backangle>`, where `<length>` defines length of each
branch of the arrow head and `<angle>` the angle (in degrees) they make
with the arrow.  `<Length>` is in x-axis units; this can be changed by
`first`, `second`, `graph`, `screen`, or `character` before the
<length>;  see `coordinates` for details.  `<Backangle>` only takes
effect when `filled` or `empty` is also used.  Then, `<backangle>` is
the angle (in degrees) the back branches make with the arrow (in the
same direction as `<angle>`).  The `fig` terminal has a restricted
backangle function. It supports three different angles. There are two
thresholds: Below 70 degrees, the arrow head gets an indented back
angle. Above 110 degrees, the arrow head has an acute back angle.
Between these thresholds, the back line is straight.

   Specifying `filled` produces filled arrow heads (if heads are used).
Filling is supported on filled-polygon capable terminals, see help of
*note pm3d:: for their list, otherwise the arrow heads are closed but
not filled.  The same result (closed but not filled arrow head) is
reached by specifying `empty`.  Further, filling and outline is
obviously not supported on terminals drawing arrows by their own
specific routines, like `metafont`, `metapost`, `latex` or `tgif`.

   The line style may be selected from a user-defined list of line
styles (see `set style line`) or may be defined here by providing
values for `<line_type>` (an index from the default list of styles)
and/or `<line_width>` (which is a  multiplier for the default width).

   Note, however, that if a user-defined line style has been selected,
its properties (type and width) cannot be altered merely by issuing
another *note arrow:: command with the appropriate index and `lt` or
`lw`.

   If `front` is given, the arrows are written on top of the graphed
data. If `back` is given (the default), the arrow is written underneath
the graphed data.  Using `front` will prevent a arrow from being
obscured by dense data.

   Examples:

   To draw an arrow without an arrow head and double width, use:
           set style arrow 1 nohead lw 2
           set arrow arrowstyle 1

   See also *note arrow:: for further examples.


File: gnuplot.info,  Node: boxplot_,  Next: set_style_data,  Prev: set_style_arrow,  Up: style

3.25.66.2 boxplot
.................

The *note boxplot:: command allows you to change the layout of plots
created using the *note boxplot:: plot style.

   Syntax:
           set style boxplot {range <r> | fraction <f>}
                             {{no}outliers} {pointtype <p>}
                             {candlesticks | financebars}
                             {separation <x>}
                             {labels off | auto | x | x2}
                             {sorted | unsorted}

   The box in the boxplot always spans the range of values from the
first quartile to the third quartile of the data points.  The limit of
the whiskers that extend from the box can be controlled in two
different ways. By default the whiskers extend from each end of the box
for a range equal to 1.5 times the interquartile range (i.e. the
vertical height of the box proper).  Each whisker is truncated back
toward the median so that it terminates at a y value belonging to some
point in the data set. Since there may be no point whose value is
exactly 1.5 times the interquartile distance, the whisker may be
shorter than its nominal range.  This default corresponds to
           set style boxplot range 1.5

   Alternatively, you can specify the fraction of the total number of
points that the whiskers should span.  In this case the range is
extended symmetrically from the median value until it encompasses the
requested fraction of the data set.  Here again each whisker is
constrained to end at a point in the data set.  To span 95% of the
points in the set
           set style boxplot fraction 0.95

   Any points that lie outside the range of the whiskers are considered
outliers.  By default these are drawn as individual circles (pointtype
7).  The option `nooutliers` disables this.

   By default boxplots are drawn in a style similar to candlesticks,
but you have the option of using instead a style similar to finance
bars.

   If the using specification for a boxplot contains a fourth column,
the values in that column will be interpreted as the discrete leveles
of a factor variable.  In this case more than one boxplots may be
drawn, as many as the number of levels of the factor variable.  These
boxplots will be drawn next to each other, the distance between them is
1.0 by default (in x-axis units).  This distance can be changed by the
option `separation`.

   The *note labels:: option governs how and where these boxplots (each
representing a part of the dataset) are labeled.  By default the value
of the factor is put as a tick label on the horizontal axis - x or x2,
depending on which one is used for the plot itself.  This setting
corresponds to option `labels auto`.  The labels can be forced to use
either of the x or x2 axes - options `labels x` and `labels x2`,
respectively -, or they can be turned off altogether with the option
`labels off`.

   By default the boxplots corresponding to different levels of the
factor variable are not sorted; they will be drawn in the same order
the levels are encountered in the data file. This behavior corresponds
to the `unsorted` option. If the `sorted` option is active, the levels
are first sorted alphabetically, and the boxplots are drawn in the
sorted order.

   The `separation`, *note labels::, `sorted` and `unsorted` option
only have an effect if a fourth column is given the plot specification.

   See *note boxplot::, *note candlesticks::, *note financebars::.


File: gnuplot.info,  Node: set_style_data,  Next: set_style_fill,  Prev: boxplot_,  Up: style

3.25.66.3 set style data
........................

The `set style data` command changes the default plotting style for data
plots.

   Syntax:
           set style data <plotting-style>
           show style data

   See `plotting styles` for the choices.  If no choice is given, the
choices are listed.  `show style data` shows the current default data
plotting style.


File: gnuplot.info,  Node: set_style_fill,  Next: set_style_function,  Prev: set_style_data,  Up: style

3.25.66.4 set style fill
........................

The `set style fill` command is used to set the default style of the
plot elements in plots with boxes, histograms, candlesticks and
filledcurves.  This default can be superseded by fillstyles attached to
individual plots.  See also 'set style rectangle'.

   Syntax:
           set style fill {empty
                           | {transparent} solid {<density>}
                           | {transparent} pattern {<n>}}
                          {border {lt} {lc <colorspec>} | noborder}

   The default fillstyle is `empty`.

   The `solid` option causes filling with a solid color, if the terminal
supports that. The <density> parameter specifies the intensity of the
fill color. At a <density> of 0.0, the box is empty, at <density> of
1.0, the inner area is of the same color as the current linetype.  Some
terminal types can vary the density continuously; others implement only
a few levels of partial fill.  If no <density> parameter is given, it
defaults to 1.

   The `pattern` option causes filling to be done with a fill pattern
supplied by the terminal driver.  The kind and number of available fill
patterns depend on the terminal driver.  If multiple datasets using
filled boxes are plotted, the pattern cycles through all available
pattern types, starting from pattern <n>, much as the line type cycles
for multiple line plots.

   The `empty` option causes filled boxes not to be filled. This is the
default.

   By default, *note border::, the box is bounded by a solid line of
the current linetype. `border <colorspec>` allows you to change the
color of the border.  `noborder` specifies that no bounding lines are
drawn.

-- SET STYLE FILL TRANSPARENT --

   Some terminals support the attribute `transparent` for filled areas.
In the case of transparent solid fill areas, the `density` parameter is
interpreted as an alpha value; that is, density 0 is fully transparent,
density 1 is fully opaque.  In the case of transparent pattern fill, the
background of the pattern is either fully transparent or fully opaque.

           terminal   solid pattern    pm3d
           --------------------------------
           gif           no     yes      no
           jpeg         yes      no     yes
           pdf          yes     yes     yes
           png    TrueColor   index     yes
           post          no     yes      no
           svg          yes      no     yes
           win          yes     yes     yes
           wxt          yes     yes     yes
           x11           no     yes      no

   Note that there may be additional limitations on the creation or
viewing of graphs containing transparent fill areas.  For example, the
png terminal can only use transparent fill if the "truecolor" option is
set.  Some pdf viewers may not correctly display the fill areas even if
they are correctly described in the pdf file. Ghostscript/gv does not
correctly display pattern-fill areas even though actual PostScript
printers generally have no problem.


File: gnuplot.info,  Node: set_style_function,  Next: set_style_increment,  Prev: set_style_fill,  Up: style

3.25.66.5 set style function
............................

The `set style function` command changes the default plotting style for
function plots (e.g. lines, points, filledcurves).  See `plotting
styles`.

   Syntax:
           set style function <plotting-style>
           show style function


File: gnuplot.info,  Node: set_style_increment,  Next: set_style_line,  Prev: set_style_function,  Up: style

3.25.66.6 set style increment
.............................

`Note`:  This command has been deprecated.  Instead please use the newer
command `set linetype`, which redefines the linetypes themselves rather
than searching for a suitable temporary line style to substitute.  See
`set linetype`

   Syntax:
           set style increment {default|userstyles}
           show style increment

   By default, successive plots within the same graph will use
successive linetypes from the default set for the current terminal type.
However, choosing `set style increment user` allows you to step through
the user-defined line styles rather than through the default linetypes.

   Example:

           set style line 1 lw 2 lc rgb "gold"
           set style line 2 lw 2 lc rgb "purple"
           set style line 4 lw 1 lc rgb "sea-green"
           set style increment user

           plot f1(x), f2(x), f3(x), f4(x)

   should plot functions f1, f2, f4 in your 3 newly defined line styles.
If a user-defined line style is not found then the corresponding default
linetype is used instead.  E.g. in the example above, f3(x) will be
plotted using the default linetype 3.


File: gnuplot.info,  Node: set_style_line,  Next: set_style_circle,  Prev: set_style_increment,  Up: style

3.25.66.7 set style line
........................

Each terminal has a default set of line and point types, which can be
seen by using the command *note test::.  `set style line` defines a set
of line types and widths and point types and sizes so that you can
refer to them later by an index instead of repeating all the
information at each invocation.

   Syntax:
           set style line <index> default
           set style line <index> {{linetype  | lt} <line_type> | <colorspec>}
                                  {{linecolor | lc} <colorspec>}
                                  {{linewidth | lw} <line_width>}
                                  {{pointtype | pt} <point_type>}
                                  {{pointsize | ps} <point_size>}
                                  {{pointinterval | pi} <interval>}
                                  {palette}
           unset style line
           show style line

   `default` sets all line style parameters to those of the linetype
with that same index.

   If the linestyle <index> already exists, only the given parameters
are changed while all others are preserved.  If not, all undefined
values are set to the default values.

   Line styles created by this mechanism do not replace the default
linetype styles; both may be used.  Line styles are temporary. They are
lost whenever you execute a *note reset:: command.  To redefine the
linetype itself, please see `set linetype`.

   The line and point types default to the index value. The exact
symbol that is drawn for that index value may vary from one terminal
type to another.

   The line width and point size are multipliers for the current
terminal's default width and size (but note that <point_size> here is
unaffected by the multiplier given by the command*note pointsize::).

   The `pointinterval` controls the spacing between points in a plot
drawn with style *note linespoints::.  The default is 0 (every point is
drawn). For example, `set style line N pi 3` defines a linestyle that
uses pointtype N, pointsize and linewidth equal to the current defaults
for the terminal, and will draw every 3rd point in plots using *note
linespoints::.  A negative value for the interval is treated the same
as a positive value, except that some terminals will try to interrupt
the line where it passes through the point symbol.

   Not all terminals support the `linewidth` and *note pointsize::
features; if not supported, the option will be ignored.

   Terminal-independent colors may be assigned using either `linecolor
<colorspec>` or `linetype <colorspec>`, abbreviated `lc` or `lt`.  This
requires giving a RGB color triple, a known palette color name, a
fractional index into the current palette, or a constant value from the
current mapping of the palette onto cbrange.  See `colors`, *note
colorspec::, *note palette::, *note colornames::, *note cbrange::.

   `set style line <n> linetype <lt>` will set both a
terminal-dependent dot/dash pattern and color. The commands`set style
line <n> linecolor <colorspec>` or `set style line <n> linetype
<colorspec>` will set a new line color while leaving the existing
dot-dash pattern unchanged.

   In 3d mode (`splot` command), the special keyword *note palette:: is
allowed as a shorthand for "linetype palette z".  The color value
corresponds to the z-value (elevation) of the splot, and varies
smoothly along a line or surface.

   Examples: Suppose that the default lines for indices 1, 2, and 3 are
red, green, and blue, respectively, and the default point shapes for
the same indices are a square, a cross, and a triangle, respectively.
Then

           set style line 1 lt 2 lw 2 pt 3 ps 0.5

   defines a new linestyle that is green and twice the default width
and a new pointstyle that is a half-sized triangle.  The commands

           set style function lines
           plot f(x) lt 3, g(x) ls 1

   will create a plot of f(x) using the default blue line and a plot of
g(x) using the user-defined wide green line.  Similarly the commands

           set style function linespoints
           plot p(x) lt 1 pt 3, q(x) ls 1

   will create a plot of p(x) using the default triangles connected by
a red line and q(x) using small triangles connected by a green line.

           splot sin(sqrt(x*x+y*y))/sqrt(x*x+y*y) w l pal

   creates a surface plot using smooth colors according to *note
palette::. Note, that this works only on some terminals. See also *note
palette::, *note pm3d::.

           set style line 10 linetype 1 linecolor rgb "cyan"

   will assign linestyle 10 to be a solid cyan line on any terminal that
supports rgb colors.


File: gnuplot.info,  Node: set_style_circle,  Next: set_style_rectangle,  Prev: set_style_line,  Up: style

3.25.66.8 set style circle
..........................

Syntax:
           set style circle {radius {graph|screen} <R>}

   This command sets the default radius used in plot style "with
circles".  It applies to data plots with only 2 columns of data (x,y)
and to function plots.  The default is "set style circle radius graph
0.02".


File: gnuplot.info,  Node: set_style_rectangle,  Next: set_style_ellipse,  Prev: set_style_circle,  Up: style

3.25.66.9 set style rectangle
.............................

Rectangles defined with the *note object:: command can have individual
styles.  However, if the object is not assigned a private style then it
inherits a default that is taken from the *note rectangle:: command.

   Syntax:
         set style rectangle {front|back} {lw|linewidth <lw>}
                             {fillcolor <colorspec>} {fs <fillstyle>}

   See *note colorspec:: and `fillstyle`.  `fillcolor` may be
abbreviated as `fc`.

   Examples:
         set style rectangle back fc rgb "white" fs solid 1.0 border lt -1
         set style rectangle fc linsestyle 3 fs pattern 2 noborder

   The default values correspond to solid fill with the background
color and a black border.


File: gnuplot.info,  Node: set_style_ellipse,  Prev: set_style_rectangle,  Up: style

3.25.66.10 set style ellipse
............................

Syntax:
           set style ellipse {units xx|xy|yy}
                             {size {graph|screen} <a>, {{graph|screen} <b>}}
                             {angle <angle>}

   This command governs whether the diameters of ellipses are
interpreted in the same units or not.  Default is `xy`, which means
that the major diameter (first axis) of ellipses will be interpreted in
the same units as the x (or x2) axis, while the minor (second) diameter
in those of the y (or y2) axis.  In this mode the ratio of the ellipse
axes depends on the scales of the plot axes and aspect ratio of the
plot.  When set to `xx` or `yy`, both axes of all ellipses will be
interpreted in the same units.  This means that the ratio of the axes
of the plotted ellipses will be correct even after rotation, but either
their vertical or horizontal extent will not be correct.

   This is a global setting that affects all ellipses, both those
defined as objects and those generated with the `plot` command,
however, the value of `units` can also be redefined on a per-plot and
per-object basis.

   It is also possible to set a default size for ellipses with the
*note size:: keyword.  This default size applies to data plots with only
2 columns of data (x,y) and to function plots.  The two values are
interpreted as the major and minor diameters (as opposed to semi-major
and semi-minor axes) of the ellipse.

   The default is "set style ellipse size graph 0.05,0.03".

   Last, but not least it is possible to set the default orientation
with the `angle` keyword. The orientation, which is defined as the
angle between the major axis of the ellipse and the plot's x axis, must
be given in degrees.

   For defining ellipse objects, see `set object ellipse`; for the 2D
plot style, see *note ellipses::.


File: gnuplot.info,  Node: surface,  Next: table,  Prev: style,  Up: set-show

3.25.67 surface
---------------

The command *note surface:: controls the display of surfaces by `splot`.

   Syntax:
           set surface
           unset surface
           show surface

   The surface is drawn with the style specified by *note with::, or
else the appropriate style, data or function.

   *note surface:: will cause `splot` to not draw points or lines
corresponding to any of the function or data file points.  If you want
to turn off the surface for an individual function or data file while
leaving the others active, use the `nosurface` keyword in the `splot`
command.  Contours may still be drawn on the surface, depending on the
*note contour:: option.  The combination `unset surface; set contour
base` is useful for displaying contours on the grid base.  See also
*note contour::.


File: gnuplot.info,  Node: table,  Next: terminal,  Prev: surface,  Up: set-show

3.25.68 table
-------------

When *note table:: mode is enabled, `plot` and `splot` commands print
out a multicolumn ASCII table of X Y {Z} R values rather than creating
an actual plot on the current terminal.  The character R takes on one
of three values: "i" if the point is in the active range, "o" if it is
out-of-range, or "u" if it is undefined.  The data format is determined
by the format of the axis labels (see `set format`), and the columns
are separated by single spaces.  This can be useful if you want to
generate contours and then save them for further use, perhaps for
plotting with `plot`;  see *note contour:: for example.  The same
method can be used to save interpolated data (see *note samples:: and
*note dgrid3d::).

   Syntax:
           set table {"outfile"}
           plot <whatever>
           unset table

   Tabular output is written to the named file, if any, otherwise it is
written to the current value of *note output::.  You must explicitly
*note table:: in order to go back to normal plotting on the current
terminal.


File: gnuplot.info,  Node: terminal,  Next: termoption,  Prev: table,  Up: set-show

3.25.69 terminal
----------------

`gnuplot` supports many different graphics devices.  Use *note
terminal:: to tell `gnuplot` what kind of output to generate. Use *note
output:: to redirect that output to a file or device.

   Syntax:
           set terminal {<terminal-type> | push | pop}
           show terminal

   If <terminal-type> is omitted, `gnuplot` will list the available
terminal types.  <terminal-type> may be abbreviated.

   If both *note terminal:: and *note output:: are used together, it is
safest to give *note terminal:: first, because some terminals set a
flag which is needed in some operating systems.

   Some terminals have many additional options.  The options used by a
previous invocation `set term <term> <options>` of a given `<term>` are
remembered, thus subsequent `set term <term>` does not reset them.
This helps in printing, for instance, when switching among different
terminals--previous options don't have to be repeated.

   The command `set term push` remembers the current terminal including
its settings while `set term pop` restores it. This is equivalent to
`save term` and `load term`, but without accessing the filesystem.
Therefore they can be used to achieve platform independent restoring of
the terminal after printing, for instance. After gnuplot's startup, the
default terminal or that from `startup` file is pushed automatically.
Therefore portable scripts can rely that `set term pop` restores the
default terminal on a given platform unless another terminal has been
pushed explicitly.

   For more information, see the `complete list of terminals`.


File: gnuplot.info,  Node: termoption,  Next: tics,  Prev: terminal,  Up: set-show

3.25.70 termoption
------------------

The *note termoption:: command allows you to change the behaviour of the
current terminal without requiring a new *note terminal:: command. Only
one option can be changed per command, and only a small number of
options can be changed this way. Currently the only options accepted are

          set termoption {no}enhanced
          set termoption font "<fontname>{,<fontsize>}"
          set termoption fontscale <scale>
          set termoption {solid|dashed}
          set termoption {linewidth <lw>}{lw <lw>}


File: gnuplot.info,  Node: tics,  Next: ticslevel,  Prev: termoption,  Up: set-show

3.25.71 tics
------------

Control of the major (labelled) tics on all axes at once is possible
with the `set tics` command.

   Fine control of the major (labelled) tics on all axes at once is
possible with the `set tics` command.  The tics may be turned off with
the `unset tics` command, and may be turned on (the default state) with
`set tics`.  Similar commands (by preceding 'tics' by the axis name)
control the major tics on a single axis.

   Syntax:
           set tics {axis | border} {{no}mirror}
                    {in | out} {scale {default | <major> {,<minor>}}}
                    {{no}rotate {by <ang>}} {offset <offset> | nooffset}
                    {left | right | center | autojustify}
                    { format "formatstring" } { font "name{,<size>}" }
                    { textcolor <colorspec> }
           set tics {front | back}
           unset tics
           show tics

   The options in the first set above can be applied individually to
any or all axes, i.e., x, y, z, x2, y2, and cb.

   Set tics `front` or `back` applies to all axes at once, but only for
2D plots (not splot).  It controls whether the tics are placed behind
or in front of the plot elements, in the case that there is overlap.

   `axis` or *note border:: tells `gnuplot` to put the tics (both the
tics themselves and the accompanying labels) along the axis or the
border, respectively.  If the axis is very close to the border, the
`axis` option will move the tic labels to outside the border in case
the border is printed (see *note border::).  The relevant margin
settings will usually be sized badly by the automatic layout algorithm
in this case.

   `mirror` tells `gnuplot` to put unlabelled tics at the same
positions on the opposite border.  `nomirror` does what you think it
does.

   `in` and `out` change the tic marks to be drawn inwards or outwards.

   With `scale`, the size of the tic marks can be adjusted. If <minor>
is not specified, it is 0.5*<major>.  The default size 1.0 for major
tics and 0.5 for minor tics is requested by `scale default`.

   `rotate` asks `gnuplot` to rotate the text through 90 degrees, which
will be done if the terminal driver in use supports text rotation.
`norotate` cancels this. `rotate by <ang>` asks for rotation by <ang>
degrees, supported by some terminal types.

   The defaults are `border mirror norotate` for tics on the x and y
axes, and `border nomirror norotate` for tics on the x2 and y2 axes.
For the z axis, the default is `nomirror`.

   The <offset> is specified by either x,y or x,y,z, and may be
preceded by `first`, `second`, `graph`, `screen`, or `character` to
select the coordinate system. <offset> is the offset of the tics texts
from their default positions, while the default coordinate system is
`character`.  See `coordinates` for details. `nooffset` switches off
the offset.

   By default, tic labels are justified automatically depending on the
axis and rotation angle to produce aesthetically pleasing results. If
this is not desired, justification can be overridden with an explicit
`left`, `right` or `center` keyword. `autojustify` restores the default
behavior.

   `set tics` with no options restores to place tics inwards. Every
other options are retained.

   See also `set xtics` for more control of major (labelled) tic marks
and *note mxtics:: for control of minor tic marks.  These commands
provide control at a axis by axis basis.


File: gnuplot.info,  Node: ticslevel,  Next: ticscale,  Prev: tics,  Up: set-show

3.25.72 ticslevel
-----------------

Deprecated. See *note xyplane::.


File: gnuplot.info,  Node: ticscale,  Next: timestamp,  Prev: ticslevel,  Up: set-show

3.25.73 ticscale
----------------

The *note ticscale:: command is deprecated, use `set tics scale`
instead.


File: gnuplot.info,  Node: timestamp,  Next: timefmt,  Prev: ticscale,  Up: set-show

3.25.74 timestamp
-----------------

The command *note timestamp:: places the time and date of the plot in
the left margin.

   Syntax:
           set timestamp {"<format>"} {top|bottom} {{no}rotate}
                         {offset <xoff>{,<yoff>}} {font "<fontspec>"}
           unset timestamp
           show timestamp

   The format string allows you to choose the format used to write the
date and time.  Its default value is what asctime() uses: "%a %b %d
%H:%M:%S %Y" (weekday, month name, day of the month, hours, minutes,
seconds, four-digit year).  With `top` or `bottom` you can place the
timestamp at the top or bottom of the left margin (default: bottom).
`rotate` lets you write the timestamp vertically, if your terminal
supports vertical text.  The constants <xoff> and <yoff> are offsets
that let you adjust the position more finely.  <font> is used to
specify the font with which the time is to be written.

   The abbreviation `time` may be used in place of *note timestamp::.

   Example:
           set timestamp "%d/%m/%y %H:%M" offset 80,-2 font "Helvetica"

   See *note timefmt:: for more information about time format strings.


File: gnuplot.info,  Node: timefmt,  Next: title_,  Prev: timestamp,  Up: set-show

3.25.75 timefmt
---------------

This command applies to timeseries where data are composed of
dates/times.  It has no meaning unless the command `set xdata time` is
given also.

   Syntax:
           set timefmt "<format string>"
           show timefmt

   The string argument tells `gnuplot` how to read timedata from the
datafile.  The valid formats are:

           Format       Explanation
           %d           day of the month, 1--31
           %m           month of the year, 1--12
           %y           year, 0--99
           %Y           year, 4-digit
           %j           day of the year, 1--365
           %H           hour, 0--24
           %M           minute, 0--60
           %s           seconds since the Unix epoch (1970-01-01, 00:00 UTC)
           %S           second, integer 0--60 on output, (double) on input
           %b           three-character abbreviation of the name of the month
           %B           name of the month

   Any character is allowed in the string, but must match exactly.  \t
(tab) is recognized.  Backslash-octals (\nnn) are converted to char.
If there is no separating character between the time/date elements,
then %d, %m, %y, %H, %M and %S read two digits each.  If a decimal
point immediately follows the field read by %S, the decimal and any
following digits are interpreted as a fractional second.  %Y reads four
digits. %j reads three digits.  %b requires three characters, and %B
requires as many as it needs.

   Spaces are treated slightly differently.  A space in the string
stands for zero or more whitespace characters in the file.  That is,
"%H %M" can be used to read "1220" and "12     20" as well as "12 20".

   Each set of non-blank characters in the timedata counts as one
column in the `using n:n` specification.  Thus `11:11  25/12/76  21.0`
consists of three columns.  To avoid confusion, `gnuplot` requires that
you provide a complete *note using:: specification if your file
contains timedata.

   If the date format includes the day or month in words, the format
string must exclude this text.  But it can still be printed with the
"%a", "%A", "%b", or "%B" specifier.  `gnuplot` will determine the
proper month and weekday from the numerical values.  See `set format`
for more details about these and other options for printing time data.

   When reading two-digit years with %y, values 69-99 refer to the 20th
century, while values 00-68 refer to the 21st century.   NB: This is in
accordance with the UNIX98 spec, but conventions vary widely and
two-digit year values are inherently ambiguous.

   See also *note xdata:: and `time/date` for more information.

   Example:
           set timefmt "%d/%m/%Y\t%H:%M"

   tells `gnuplot` to read date and time separated by tab.  (But look
closely at your data--what began as a tab may have been converted to
spaces somewhere along the line; the format string must match what is
actually in the file.)  See also time data demo.
(http://www.gnuplot.info/demo/timedat.html)


File: gnuplot.info,  Node: title_,  Next: tmargin,  Prev: timefmt,  Up: set-show

3.25.76 title
-------------

The *note title:: command produces a plot title that is centered at the
top of the plot.  *note title:: is a special case of `set label`.

   Syntax:
           set title {"<title-text>"} {offset <offset>} {font "<font>{,<size>}"}
                     {{textcolor | tc} {<colorspec> | default}} {{no}enhanced}
           show title

   If <offset> is specified by either x,y or x,y,z the title is moved
by the given offset.  It may be preceded by `first`, `second`, `graph`,
`screen`, or `character` to select the coordinate system.  See
`coordinates` for details.  By default, the `character` coordinate
system is used.  For example, "`set title offset 0,-1`" will change
only the y offset of the title, moving the title down by roughly the
height of one character.  The size of a character depends on both the
font and the terminal.

   <font> is used to specify the font with which the title is to be
written; the units of the font <size> depend upon which terminal is
used.

   `textcolor <colorspec>` changes the color of the text. <colorspec>
can be a linetype, an rgb color, or a palette mapping. See help for
*note colorspec:: and *note palette::.

   `noenhanced` requests that the title not be processed by the
enhanced text mode parser, even if enhanced text mode is currently
active.

   *note title:: with no parameters clears the title.

   See `syntax` for details about the processing of backslash sequences
and the distinction between single- and double-quotes.


File: gnuplot.info,  Node: tmargin,  Next: trange,  Prev: title_,  Up: set-show

3.25.77 tmargin
---------------

The command *note tmargin:: sets the size of the top margin.  Please
see *note margin:: for details.


File: gnuplot.info,  Node: trange,  Next: urange,  Prev: tmargin,  Up: set-show

3.25.78 trange
--------------

The *note trange:: command sets the parametric range used to compute x
and y values when in parametric or polar modes.  Please see *note
xrange:: for details.


File: gnuplot.info,  Node: urange,  Next: variables,  Prev: trange,  Up: set-show

3.25.79 urange
--------------

The *note urange:: and *note vrange:: commands set the parametric
ranges used to compute x, y, and z values when in `splot` parametric
mode.  Please see *note xrange:: for details.


File: gnuplot.info,  Node: variables,  Next: version,  Prev: urange,  Up: set-show

3.25.80 variables
-----------------

The *note variables:: command lists the current value of user-defined
and internal variables. Gnuplot internally defines variables whose
names begin with GPVAL_, MOUSE_, FIT_, and TERM_.

   Syntax:
           show variables      # show variables that do not begin with GPVAL_
           show variables all  # show all variables including those beginning GPVAL_
           show variables NAME # show only variables beginning with NAME


File: gnuplot.info,  Node: version,  Next: view,  Prev: variables,  Up: set-show

3.25.81 version
---------------

The *note version:: command lists the version of gnuplot being run, its
last modification date, the copyright holders, and email addresses for
the FAQ, the gnuplot-info mailing list, and reporting bugs-in short,
the information listed on the screen when the program is invoked
interactively.

   Syntax:
           show version {long}

   When the `long` option is given, it also lists the operating system,
the compilation options used when `gnuplot` was installed, the location
of the help file, and (again) the useful email addresses.


File: gnuplot.info,  Node: view,  Next: vrange,  Prev: version,  Up: set-show

3.25.82 view
------------

The *note view:: command sets the viewing angle for `splot`s.  It
controls how the 3D coordinates of the plot are mapped into the 2D
screen space.  It provides controls for both rotation and scaling of
the plotted data, but supports orthographic projections only.  It
supports both 3D projection or orthogonal 2D projection into a 2D
plot-like map.

   Syntax:
           set view <rot_x>{,{<rot_z>}{,{<scale>}{,<scale_z>}}}
           set view map
           set view {no}equal {xy|xyz}
           show view

   where <rot_x> and <rot_z> control the rotation angles (in degrees)
in a virtual 3D coordinate system aligned with the screen such that
initially (that is, before the rotations are performed) the screen
horizontal axis is x, screen vertical axis is y, and the axis
perpendicular to the screen is z.  The first rotation applied is
<rot_x> around the x axis.  The second rotation applied is <rot_z>
around the new z axis.

   Command `set view map` is used to represent the drawing as a map. It
can be used for *note contour:: plots, or for color *note pm3d:: maps.
In the latter, take care that you properly use *note zrange:: and *note
cbrange:: for input data point filtering and color range scaling,
respectively.

   <rot_x> is bounded to the [0:180] range with a default of 60
degrees, while <rot_z> is bounded to the [0:360] range with a default
of 30 degrees.  <scale> controls the scaling of the entire `splot`,
while <scale_z> scales the z axis only.  Both scales default to 1.0.

   Examples:
           set view 60, 30, 1, 1
           set view ,,0.5

   The first sets all the four default values.  The second changes only
scale, to 0.5.

* Menu:

* equal_axes::


File: gnuplot.info,  Node: equal_axes,  Prev: view,  Up: view

3.25.82.1 equal_axes
....................

The command `set view equal xy` forces the unit length of the x and y
axes to be on the same scale, and chooses that scale so that the plot
will fit on the page.  The command `set view equal xyz` additionally
sets the z axis scale to match the x and y axes; however there is no
guarantee that the current z axis range will fit within the plot
boundary.  By default all three axes are scaled independently to fill
the available area.

   See also *note xyplane::.


File: gnuplot.info,  Node: vrange,  Next: x2data,  Prev: view,  Up: set-show

3.25.83 vrange
--------------

The *note urange:: and *note vrange:: commands set the parametric
ranges used to compute x, y, and z values when in `splot` parametric
mode.  Please see *note xrange:: for details.


File: gnuplot.info,  Node: x2data,  Next: x2dtics,  Prev: vrange,  Up: set-show

3.25.84 x2data
--------------

The *note x2data:: command sets data on the x2 (top) axis to timeseries
(dates/times).  Please see *note xdata::.


File: gnuplot.info,  Node: x2dtics,  Next: x2label,  Prev: x2data,  Up: set-show

3.25.85 x2dtics
---------------

The *note x2dtics:: command changes tics on the x2 (top) axis to days
of the week.  Please see *note xdtics:: for details.


File: gnuplot.info,  Node: x2label,  Next: x2mtics,  Prev: x2dtics,  Up: set-show

3.25.86 x2label
---------------

The *note x2label:: command sets the label for the x2 (top) axis.
Please see *note xlabel::.


File: gnuplot.info,  Node: x2mtics,  Next: x2range,  Prev: x2label,  Up: set-show

3.25.87 x2mtics
---------------

The *note x2mtics:: command changes tics on the x2 (top) axis to months
of the year.  Please see *note xmtics:: for details.


File: gnuplot.info,  Node: x2range,  Next: x2tics,  Prev: x2mtics,  Up: set-show

3.25.88 x2range
---------------

The *note x2range:: command sets the horizontal range that will be
displayed on the x2 (top) axis.  Please see *note xrange:: for details.


File: gnuplot.info,  Node: x2tics,  Next: x2zeroaxis,  Prev: x2range,  Up: set-show

3.25.89 x2tics
--------------

The *note x2tics:: command controls major (labelled) tics on the x2
(top) axis.  Please see `set xtics` for details.


File: gnuplot.info,  Node: x2zeroaxis,  Next: xdata,  Prev: x2tics,  Up: set-show

3.25.90 x2zeroaxis
------------------

The *note x2zeroaxis:: command draws a line at the origin of the x2
(top) axis (y2 = 0).  For details, please see *note zeroaxis::.


File: gnuplot.info,  Node: xdata,  Next: xdtics,  Prev: x2zeroaxis,  Up: set-show

3.25.91 xdata
-------------

This command sets the datatype on the x axis to time/date.  A similar
command does the same thing for each of the other axes.

   Syntax:
           set xdata {time}
           show xdata

   The same syntax applies to *note ydata::, *note zdata::, *note
x2data::, *note y2data:: and *note cbdata::.

   The `time` option signals that the datatype is indeed time/date.  If
the option is not specified, the datatype reverts to normal.

   See *note timefmt:: to tell gnuplot how to read date or time data.
The time/date is converted to seconds from start of the century.  There
is currently only one timefmt, which implies that all the time/date
columns must conform to this format.  Specification of ranges should be
supplied as quoted strings according to this format to avoid
interpretation of the time/date as an expression.

   The function 'strftime' (type "man strftime" on unix to look it up)
is used to print tic-mark labels.  `gnuplot` tries to figure out a
reasonable format for this  unless the `set format x "string"` has
supplied something that does not look like a decimal format (more than
one '%' or neither %f nor %g).

   See also `time/date` for more information.


File: gnuplot.info,  Node: xdtics,  Next: xlabel,  Prev: xdata,  Up: set-show

3.25.92 xdtics
--------------

The *note xdtics:: commands converts the x-axis tic marks to days of
the week where 0=Sun and 6=Sat.  Overflows are converted modulo 7 to
dates.  `set noxdtics` returns the labels to their default values.
Similar commands do the same things for the other axes.

   Syntax:
           set xdtics
           unset xdtics
           show xdtics

   The same syntax applies to *note ydtics::, *note zdtics::, *note
x2dtics::, *note y2dtics:: and *note cbdtics::.

   See also the `set format` command.


File: gnuplot.info,  Node: xlabel,  Next: xmtics,  Prev: xdtics,  Up: set-show

3.25.93 xlabel
--------------

The *note xlabel:: command sets the x axis label.  Similar commands set
labels on the other axes.

   Syntax:
           set xlabel {"<label>"} {offset <offset>} {font "<font>{,<size>}"}
                      {textcolor <colorspec>} {{no}enhanced}
                      {rotate by <degrees> | rotate parallel | norotate}
           show xlabel

   The same syntax applies to *note x2label::, *note ylabel::, *note
y2label::, *note zlabel:: and *note cblabel::.

   If <offset> is specified by either x,y or x,y,z the label is moved
by the given offset.  It may be preceded by `first`, `second`, `graph`,
`screen`, or `character` to select the coordinate system.  See
`coordinates` for details.  By default, the `character` coordinate
system is used.  For example, "`set xlabel offset -1,0`" will change
only the x offset of the title, moving the label roughly one character
width to the left.  The size of a character depends on both the font
and the terminal.

   <font> is used to specify the font in which the label is written;
the units of the font <size> depend upon which terminal is used.

   `noenhanced` requests that the label text not be processed by the
enhanced text mode parser, even if enhanced text mode is currently
active.

   To clear a label, put no options on the command line, e.g., "*note
y2label::".

   The default positions of the axis labels are as follows:

   xlabel:  The x-axis label is centered below the bottom of the plot.

   ylabel:  The y-axis label is centered to the left of the plot,
defaulting to either horizontal or vertical orientation depending on
the terminal type.

   zlabel: The z-axis label is centered along the z axis and placed in
the space above the grid level.

   cblabel: The color box axis label is centered along the box and
placed below or to the right according to horizontal or vertical color
box gradient.

   y2label: The y2-axis label is placed to the right of the y2 axis.
The position is terminal-dependent in the same manner as is the y-axis
label.

   x2label: The x2-axis label is placed above the plot but below the
title.  It is also possible to create an x2-axis label by using new-line
characters to make a multi-line plot title, e.g.,

           set title "This is the title\n\nThis is the x2label"

   Note that double quotes must be used.  The same font will be used
for both lines, of course.

   The orientation (rotation angle) of the x, x2, y and y2 axis labels
in 2D plots can be changed by specifying `rotate by <degrees>`.  The
orientation of the x and y axis labels in 3D plots defaults to
horizontal but can be changed to run parallel to the axis by specifying
`rotate parallel`.

   If you are not satisfied with the default position of an axis label,
use `set label` instead-that command gives you much more control over
where text is placed.

   Please see `syntax` for further information about backslash
processing and the difference between single- and double-quoted strings.


File: gnuplot.info,  Node: xmtics,  Next: xrange,  Prev: xlabel,  Up: set-show

3.25.94 xmtics
--------------

The *note xmtics:: command converts the x-axis tic marks to months of
the year where 1=Jan and 12=Dec.  Overflows are converted modulo 12 to
months.  The tics are returned to their default labels by *note
xmtics::.  Similar commands perform the same duties for the other axes.

   Syntax:
           set xmtics
           unset xmtics
           show xmtics

   The same syntax applies to *note x2mtics::, *note ymtics::, *note
y2mtics::, *note zmtics:: and *note cbmtics::.

   See also the `set format` command.


File: gnuplot.info,  Node: xrange,  Next: xtics,  Prev: xmtics,  Up: set-show

3.25.95 xrange
--------------

The *note xrange:: command sets the horizontal range that will be
displayed.  A similar command exists for each of the other axes, as
well as for the polar radius r and the parametric variables t, u, and v.

   Syntax:
           set xrange { [{{<min>}:{<max>}}] {{no}reverse} {{no}writeback} }
                      | restore
           show xrange

   where <min> and <max> terms are constants, expressions or an
asterisk to set autoscaling.  See below for full autoscaling syntax.
If the data are time/date, you must give the range as a quoted string
according to the *note timefmt:: format.  Any value omitted will not be
changed.

   The same syntax applies to *note yrange::, *note zrange::, *note
x2range::, *note y2range::, *note cbrange::, *note rrange::, *note
trange::, *note urange:: and *note vrange::.

   The `reverse` option reverses the direction of the axis, e.g., `set
xrange [0:1] reverse` will produce an axis with 1 on the left and 0 on
the right.  This is identical to the axis produced by `set xrange
[1:0]`, of course.  `reverse` is intended primarily for use with *note
autoscale::.

   Autoscaling:  If <min> (the same applies for correspondingly to
<max>) is an asterisk "*" autoscaling is turned on.  The range in which
autoscaling is being performed may be limited by a lower bound <lb> or
an upper bound <ub> or both.  The syntax is
           { <lb> < } * { < <ub> }

   For example,
           0 < * < 200

   sets <lb> = 0 and <ub> = 200.  With such a setting <min> would be
autoscaled, but its final value will be between 0 and 200 (both
inclusive despite the '<' sign).  If no lower or upper bound is
specified, the '<' to also be ommited.  If <ub> is lower than <lb> the
constraints will be turned off and full autoscaling will happen.  This
feature is useful to plot measured data with autoscaling but providing
a limit on the range, to clip outliers, or to guarantee a minimum range
that will be displayed even if the data would not need such a big range.

   The `writeback` option essentially saves the range found by *note
autoscale:: in the buffers that would be filled by *note xrange::.
This is useful if you wish to plot several functions together but have
the range determined by only some of them.  The `writeback` operation
is performed during the `plot` execution, so it must be specified
before that command.  To restore, the last saved horizontal range use
`set xrange restore`.  For example,

           set xrange [-10:10]
           set yrange [] writeback
           plot sin(x)
           set yrange restore
           replot x/2

   results in a yrange of [-1:1] as found only from the range of
sin(x); the [-5:5] range of x/2 is ignored.  Executing *note yrange::
after each command in the above example should help you understand what
is going on.

   In 2D, *note xrange:: and *note yrange:: determine the extent of the
axes, *note trange:: determines the range of the parametric variable in
parametric mode or the range of the angle in polar mode.  Similarly in
parametric 3D, *note xrange::, *note yrange::, and *note zrange::
govern the axes and *note urange:: and *note vrange:: govern the
parametric variables.

   In polar mode, *note rrange:: determines the radial range plotted.
<rmin> acts as an additive constant to the radius, whereas <rmax> acts
as a clip to the radius--no point with radius greater than <rmax> will
be plotted.  *note xrange:: and *note yrange:: are affected--the ranges
can be set as if the graph was of r(t)-rmin, with rmin added to all the
labels.

   Any range may be partially or totally autoscaled, although it may
not make sense to autoscale a parametric variable unless it is plotted
with data.

   Ranges may also be specified on the `plot` command line.  A range
given on the plot line will be used for that single `plot` command; a
range given by a `set` command will be used for all subsequent plots
that do not specify their own ranges.  The same holds true for `splot`.

   Examples:

   To set the xrange to the default:
           set xrange [-10:10]

   To set the yrange to increase downwards:
           set yrange [10:-10]

   To change zmax to 10 without affecting zmin (which may still be
autoscaled):
           set zrange [:10]

   To autoscale xmin while leaving xmax unchanged:
           set xrange [*:]

   To autoscale xmin but keeping xmin positive:
           set xrange [0<*:]

   To autoscale x but keep minimum range of 10 to 50 (actual might be
larger):
           set xrange [*<10:50<*]

   Autoscaling but limit maximum xrange to -1000 to 1000, i.e.
autoscaling within [-1000:1000]
           set xrange [-1000<*:*<1000]

   Make sure xmin is somewhere between -200 and 100:
           set xrange [-200<*<100:]


File: gnuplot.info,  Node: xtics,  Next: xyplane,  Prev: xrange,  Up: set-show

3.25.96 xtics
-------------

Fine control of the major (labelled) tics on the x axis is possible
with the `set xtics` command.  The tics may be turned off with the
`unset xtics` command, and may be turned on (the default state) with
`set xtics`.  Similar commands control the major tics on the y, z, x2
and y2 axes.

   Syntax:
           set xtics {axis | border} {{no}mirror}
                     {in | out} {scale {default | <major> {,<minor>}}}
                     {{no}rotate {by <ang>}} {offset <offset> | nooffset}
                     {left | right | center | autojustify}
                     {add}
                     {  autofreq
                      | <incr>
                      | <start>, <incr> {,<end>}
                      | ({"<label>"} <pos> {<level>} {,{"<label>"}...) }
                     { format "formatstring" } { font "name{,<size>}" }
                     { rangelimited }
                     { textcolor <colorspec> }
           unset xtics
           show xtics

   The same syntax applies to *note ytics::, *note ztics::, *note
x2tics::, *note y2tics:: and *note cbtics::.

   `axis` or *note border:: tells `gnuplot` to put the tics (both the
tics themselves and the accompanying labels) along the axis or the
border, respectively.  If the axis is very close to the border, the
`axis` option will move the tic labels to outside the border.  The
relevant margin settings will usually be sized badly by the automatic
layout algorithm in this case.

   `mirror` tells `gnuplot` to put unlabelled tics at the same
positions on the opposite border.  `nomirror` does what you think it
does.

   `in` and `out` change the tic marks to be drawn inwards or outwards.

   With `scale`, the size of the tic marks can be adjusted. If <minor>
is not specified, it is 0.5*<major>.  The default size 1.0 for major
tics and 0.5 for minor tics is requested by `scale default`.

   `rotate` asks `gnuplot` to rotate the text through 90 degrees, which
will be done if the terminal driver in use supports text rotation.
`norotate` cancels this. `rotate by <ang>` asks for rotation by <ang>
degrees, supported by some terminal types.

   The defaults are `border mirror norotate` for tics on the x and y
axes, and `border nomirror norotate` for tics on the x2 and y2 axes.
For the z axis, the `{axis | border}` option is not available and the
default is `nomirror`.  If you do want to mirror the z-axis tics, you
might want to create a bit more room for them with *note border::.

   The <offset> is specified by either x,y or x,y,z, and may be
preceded by `first`, `second`, `graph`, `screen`, or `character` to
select the coordinate system. <offset> is the offset of the tics texts
from their default positions, while the default coordinate system is
`character`.  See `coordinates` for details. `nooffset` switches off
the offset.

   Example:

   Move xtics more closely to the plot.
           set xtics offset 0,graph 0.05

   By default, tic labels are justified automatically depending on the
axis and rotation angle to produce aesthetically pleasing results. If
this is not desired, justification can be overridden with an explicit
`left`, `right` or `center` keyword. `autojustify` restores the default
behavior.

   `set xtics` with no options restores the default border or axis if
xtics are being displayed;  otherwise it has no effect.  Any previously
specified tic frequency or position {and labels} are retained.

   Positions of the tics are calculated automatically by default or if
the `autofreq` option is given; otherwise they may be specified in
either of two forms:

   The implicit <start>, <incr>, <end> form specifies that a series of
tics will be plotted on the axis between the values <start> and <end>
with an increment of <incr>.  If <end> is not given, it is assumed to
be infinity.  The increment may be negative.  If neither <start> nor
<end> is given, <start> is assumed to be negative infinity, <end> is
assumed to be positive infinity, and the tics will be drawn at integral
multiples of <incr>.  If the axis is logarithmic, the increment will be
used as a multiplicative factor.

   If you specify to a negative <start> or <incr> after a numerical
value (e.g., `rotate by <angle>` or `offset <offset>`), the parser
fails because it subtracts <start> or <incr> from that value.  As a
workaround, specify `0-<start>` resp. `0-<incr>` in that case.

   Example:
           set xtics border offset 0,0.5 -5,1,5

   Fails with 'invalid expression' at the last comma.
           set xtics border offset 0,0.5 0-5,1,5

   or
           set xtics offset 0,0.5 border -5,1,5

   Sets tics at the border, tics text with an offset of 0,0.5
characters, and sets the start, increment, and end to -5, 1, and 5, as
requested.

   The `set grid` options 'front', 'back' and 'layerdefault' affect the
drawing order of the xtics, too.

   Examples:

   Make tics at 0, 0.5, 1, 1.5, ..., 9.5, 10.
           set xtics 0,.5,10

   Make tics at ..., -10, -5, 0, 5, 10, ...
           set xtics 5

   Make tics at 1, 100, 1e4, 1e6, 1e8.
           set logscale x; set xtics 1,100,1e8

   The explicit ("<label>" <pos> <level>, ...) form allows arbitrary tic
positions or non-numeric tic labels.  In this form, the tics do not
need to be listed in numerical order.  Each tic has a position,
optionally with a label.  Note that the label is a string enclosed by
quotes.  It may be a constant string, such as "hello", may contain
formatting information for converting the position into its label, such
as "%3f clients", or may be empty, "".  See `set format` for more
information.  If no string is given, the default label (numerical) is
used.

   An explicit tic mark has a third parameter, the "level".  The default
is level 0, a major tic.  A level of 1 generates a minor tic.  If the
level is specified, then the label must also be supplied.

   Examples:
           set xtics ("low" 0, "medium" 50, "high" 100)
           set xtics (1,2,4,8,16,32,64,128,256,512,1024)
           set ytics ("bottom" 0, "" 10, "top" 20)
           set ytics ("bottom" 0, "" 10 1, "top" 20)

   In the second example, all tics are labelled.  In the third, only
the end tics are labelled.  In the fourth, the unlabeled tic is a minor
tic.

   Normally if explicit tics are given, they are used instead of
auto-generated tics. Conversely if you specify `set xtics auto` or the
like it will erase any previously specified explicit tics. You can mix
explicit and auto- generated tics by using the keyword `add`, which
must appear before the tic style being added.

   Example:
           set xtics 0,.5,10
           set xtics add ("Pi" 3.14159)

   This will automatically generate tic marks every 0.5 along x, but
will also add an explicit labeled tic mark at pi.

   However they are specified, tics will only be plotted when in range.

   Format (or omission) of the tic labels is controlled by `set
format`, unless the explicit text of a label is included in the `set
xtics ("<label>")` form.

   Minor (unlabelled) tics can be added automatically by the *note
mxtics:: command, or at explicit positions by the `set xtics ("" <pos>
1, ...)` form.

* Menu:

* xtics_time_data::
* xtics_rangelimited::


File: gnuplot.info,  Node: xtics_time_data,  Next: xtics_rangelimited,  Prev: xtics,  Up: xtics

3.25.96.1 xtics time_data
.........................

In case of timeseries data, axis tic position values must be given as
quoted dates or times according to the format *note timefmt::. If the
<start>, <incr>, <end> form is used, <start> and <end> must be given
according to *note timefmt::, but <incr> must be in seconds.  Times
will be written out according to the format given on `set format`,
however.

   Examples:
           set xdata time
           set timefmt "%d/%m"
           set xtics format "%b %d"
           set xrange ["01/12":"06/12"]
           set xtics "01/12", 172800, "05/12"

           set xdata time
           set timefmt "%d/%m"
           set xtics format "%b %d"
           set xrange ["01/12":"06/12"]
           set xtics ("01/12", "" "03/12", "05/12")

   Both of these will produce tics "Dec 1", "Dec 3", and "Dec 5", but
in the second example the tic at "Dec 3" will be unlabelled.


File: gnuplot.info,  Node: xtics_rangelimited,  Prev: xtics_time_data,  Up: xtics

3.25.96.2 xtics rangelimited
............................

This option limits both the auto-generated axis tic labels and the
corresponding plot border to the range of values actually present in
the data that has been plotted.  Note that this is independent of the
current range limits for the plot. For example, suppose that the data
in "file.dat" all lies in the range 2 < y < 4.  Then the following
commands will create a plot for which the left-hand plot border (y
axis) is drawn for only this portion of the total y range, and only the
axis tics in this region are generated.  I.e., the plot will be scaled
to the full range on y, but there will be a gap between 0 and 2 on the
left border and another gap between 4 and 10. This style is sometimes
referred to as a `range-frame` graph.
           set border 3
           set yrange [0:10]
           set ytics nomirror rangelimited
           plot "file.dat"


File: gnuplot.info,  Node: xyplane,  Next: xzeroaxis,  Prev: xtics,  Up: set-show

3.25.97 xyplane
---------------

The *note xyplane:: command adjusts the position at which the xy plane
is drawn in a 3D plot.  The synonym "set ticslevel" is accepted for
backwards compatibility.

   Syntax:
           set xyplane at <zvalue>
           set xyplane relative <frac>
           set ticslevel <frac>        # equivalent to set xyplane relative
           show xyplane

   The form `set xyplane relative <frac>` places the xy plane below the
range in Z, where the distance from the xy plane to Zmin is given as a
fraction of the total range in z.  The default value is 0.5.  Negative
values are permitted, but tic labels on the three axes may overlap.
The older, deprecated, form *note ticslevel:: is retained for backwards
compatibility.

   To place the xy-plane at a position 'pos' on the z-axis, *note
ticslevel:: may be set equal to  (pos - zmin) / (zmin - zmax).
However, this position will change if the z range is changed.

   The alternative form `set xyplane at <zvalue>` fixes the placement
of the xy plane at a specific Z value regardless of the current z
range. Thus to force the x, y, and z axes to meet at a common origin
one would specify `set xyplane at 0`.

   See also *note view::, and *note zeroaxis::.


File: gnuplot.info,  Node: xzeroaxis,  Next: y2data,  Prev: xyplane,  Up: set-show

3.25.98 xzeroaxis
-----------------

The *note xzeroaxis:: command draws a line at y = 0.  For details,
please see *note zeroaxis::.


File: gnuplot.info,  Node: y2data,  Next: y2dtics,  Prev: xzeroaxis,  Up: set-show

3.25.99 y2data
--------------

The *note y2data:: command sets y2 (right-hand) axis data to timeseries
(dates/times).  Please see *note xdata::.


File: gnuplot.info,  Node: y2dtics,  Next: y2label,  Prev: y2data,  Up: set-show

3.25.100 y2dtics
----------------

The *note y2dtics:: command changes tics on the y2 (right-hand) axis to
days of the week.  Please see *note xdtics:: for details.


File: gnuplot.info,  Node: y2label,  Next: y2mtics,  Prev: y2dtics,  Up: set-show

3.25.101 y2label
----------------

The *note y2label:: command sets the label for the y2 (right-hand) axis.
Please see *note xlabel::.


File: gnuplot.info,  Node: y2mtics,  Next: y2range,  Prev: y2label,  Up: set-show

3.25.102 y2mtics
----------------

The *note y2mtics:: command changes tics on the y2 (right-hand) axis to
months of the year.  Please see *note xmtics:: for details.


File: gnuplot.info,  Node: y2range,  Next: y2tics,  Prev: y2mtics,  Up: set-show

3.25.103 y2range
----------------

The *note y2range:: command sets the vertical range that will be
displayed on the y2 (right-hand) axis.  Please see *note xrange:: for
details.


File: gnuplot.info,  Node: y2tics,  Next: y2zeroaxis,  Prev: y2range,  Up: set-show

3.25.104 y2tics
---------------

The *note y2tics:: command controls major (labelled) tics on the y2
(right-hand) axis.  Please see `set xtics` for details.


File: gnuplot.info,  Node: y2zeroaxis,  Next: ydata,  Prev: y2tics,  Up: set-show

3.25.105 y2zeroaxis
-------------------

The *note y2zeroaxis:: command draws a line at the origin of the y2
(right-hand) axis (x2 = 0).  For details, please see *note zeroaxis::.


File: gnuplot.info,  Node: ydata,  Next: ydtics,  Prev: y2zeroaxis,  Up: set-show

3.25.106 ydata
--------------

The *note ydata:: commands sets y-axis data to timeseries (dates/times).
Please see *note xdata::.


File: gnuplot.info,  Node: ydtics,  Next: ylabel,  Prev: ydata,  Up: set-show

3.25.107 ydtics
---------------

The *note ydtics:: command changes tics on the y axis to days of the
week.  Please see *note xdtics:: for details.


File: gnuplot.info,  Node: ylabel,  Next: ymtics,  Prev: ydtics,  Up: set-show

3.25.108 ylabel
---------------

This command sets the label for the y axis.  Please see *note xlabel::.


File: gnuplot.info,  Node: ymtics,  Next: yrange,  Prev: ylabel,  Up: set-show

3.25.109 ymtics
---------------

The *note ymtics:: command changes tics on the y axis to months of the
year.  Please see *note xmtics:: for details.


File: gnuplot.info,  Node: yrange,  Next: ytics,  Prev: ymtics,  Up: set-show

3.25.110 yrange
---------------

The *note yrange:: command sets the vertical range that will be
displayed on the y axis.  Please see *note xrange:: for details.


File: gnuplot.info,  Node: ytics,  Next: yzeroaxis,  Prev: yrange,  Up: set-show

3.25.111 ytics
--------------

The *note ytics:: command controls major (labelled) tics on the y axis.
Please see `set xtics` for details.


File: gnuplot.info,  Node: yzeroaxis,  Next: zdata,  Prev: ytics,  Up: set-show

3.25.112 yzeroaxis
------------------

The *note yzeroaxis:: command draws a line at x = 0.  For details,
please see *note zeroaxis::.


File: gnuplot.info,  Node: zdata,  Next: zdtics,  Prev: yzeroaxis,  Up: set-show

3.25.113 zdata
--------------

The *note zdata:: command sets zaxis data to timeseries (dates/times).
Please see *note xdata::.


File: gnuplot.info,  Node: zdtics,  Next: zzeroaxis,  Prev: zdata,  Up: set-show

3.25.114 zdtics
---------------

The *note zdtics:: command changes tics on the z axis to days of the
week.  Please see *note xdtics:: for details.


File: gnuplot.info,  Node: zzeroaxis,  Next: cbdata,  Prev: zdtics,  Up: set-show

3.25.115 zzeroaxis
------------------

The *note zzeroaxis:: command draws a line through (x=0,y=0).  This has
no effect on 2D plots, including splot with `set view map`. For
details, please see *note zeroaxis:: and *note xyplane::.


File: gnuplot.info,  Node: cbdata,  Next: cbdtics,  Prev: zzeroaxis,  Up: set-show

3.25.116 cbdata
---------------

Set color box axis data to timeseries (dates/times).  Please see *note
xdata::.


File: gnuplot.info,  Node: cbdtics,  Next: zero,  Prev: cbdata,  Up: set-show

3.25.117 cbdtics
----------------

The *note cbdtics:: command changes tics on the color box axis to days
of the week. Please see *note xdtics:: for details.


File: gnuplot.info,  Node: zero,  Next: zeroaxis,  Prev: cbdtics,  Up: set-show

3.25.118 zero
-------------

The `zero` value is the default threshold for values approaching 0.0.

   Syntax:
           set zero <expression>
           show zero

   `gnuplot` will not plot a point if its imaginary part is greater in
magnitude than the `zero` threshold.  This threshold is also used in
various other parts of `gnuplot` as a (crude) numerical-error
threshold.  The default `zero` value is 1e-8.  `zero` values larger
than 1e-3 (the reciprocal of the number of pixels in a typical bitmap
display) should probably be avoided, but it is not unreasonable to set
`zero` to 0.0.


File: gnuplot.info,  Node: zeroaxis,  Next: zlabel,  Prev: zero,  Up: set-show

3.25.119 zeroaxis
-----------------

The x axis may be drawn by *note xzeroaxis:: and removed by *note
xzeroaxis::.  Similar commands behave similarly for the y, x2, y2, and
z axes.

   Syntax:
           set {x|x2|y|y2|z}zeroaxis { {linestyle | ls <line_style>}
                                      | { linetype | lt <line_type>}
                                        { linewidth | lw <line_width>}}
           unset {x|x2|y|y2|z}zeroaxis
           show {x|y|z}zeroaxis

   By default, these options are off.  The selected zero axis is drawn
with a line of type <line_type> and width <line_width> (if supported by
the terminal driver currently in use), or a user-defined style
<line_style>.

   If no linetype is specified, any zero axes selected will be drawn
using the axis linetype (linetype 0).

   *note zeroaxis:: is equivalent to *note yzeroaxis::.  Note that the
z-axis must be set separately using *note zzeroaxis::.

   Examples:

   To simply have the y=0 axis drawn visibly:

            set xzeroaxis

   If you want a thick line in a different color or pattern, instead:

            set xzeroaxis linetype 3 linewidth 2.5


File: gnuplot.info,  Node: zlabel,  Next: zmtics,  Prev: zeroaxis,  Up: set-show

3.25.120 zlabel
---------------

This command sets the label for the z axis.  Please see *note xlabel::.


File: gnuplot.info,  Node: zmtics,  Next: zrange,  Prev: zlabel,  Up: set-show

3.25.121 zmtics
---------------

The *note zmtics:: command changes tics on the z axis to months of the
year.  Please see *note xmtics:: for details.


File: gnuplot.info,  Node: zrange,  Next: ztics,  Prev: zmtics,  Up: set-show

3.25.122 zrange
---------------

The *note zrange:: command sets the range that will be displayed on the
z axis.  The zrange is used only by `splot` and is ignored by `plot`.
Please see *note xrange:: for details.


File: gnuplot.info,  Node: ztics,  Next: cblabel,  Prev: zrange,  Up: set-show

3.25.123 ztics
--------------

The *note ztics:: command controls major (labelled) tics on the z axis.
Please see `set xtics` for details.


File: gnuplot.info,  Node: cblabel,  Next: cbmtics,  Prev: ztics,  Up: set-show

3.25.124 cblabel
----------------

This command sets the label for the color box axis.  Please see *note
xlabel::.


File: gnuplot.info,  Node: cbmtics,  Next: cbrange,  Prev: cblabel,  Up: set-show

3.25.125 cbmtics
----------------

The *note cbmtics:: command changes tics on the color box axis to
months of the year. Please see *note xmtics:: for details.


File: gnuplot.info,  Node: cbrange,  Next: cbtics,  Prev: cbmtics,  Up: set-show

3.25.126 cbrange
----------------

The *note cbrange:: command sets the range of values which are colored
using the current *note palette:: by styles *note pm3d::, `with image`
and *note palette::.  Values outside of the color range use color of
the nearest extreme.

   If the cb-axis is autoscaled in `splot`, then the colorbox range is
taken from *note zrange::.  Points drawn in `splot ... pm3d|palette`
can be filtered by using different *note zrange:: and *note cbrange::.

   Please see *note xrange:: for details on *note cbrange:: syntax. See
also *note palette:: and `set colorbox`.


File: gnuplot.info,  Node: cbtics,  Prev: cbrange,  Up: set-show

3.25.127 cbtics
---------------

The *note cbtics:: command controls major (labelled) tics on the color
box axis.  Please see `set xtics` for details.


File: gnuplot.info,  Node: shell,  Next: splot,  Prev: set-show,  Up: Commands

3.26 shell
==========

The *note shell:: command spawns an interactive shell.  To return to
`gnuplot`, type `logout` if using VMS, *note exit:: or the END-OF-FILE
character if using Unix, or *note exit:: if using MS-DOS or OS/2.

   There are two ways of spawning a shell command: using *note system::
command or via `!` ($ if using VMS). The former command takes a string
as a parameter and thus it can be used anywhere among other gnuplot
commands, while the latter syntax requires to be the only command on
the line. Control will return immediately to `gnuplot` after this
command is executed.  For example, in MS-DOS or OS/2,

           ! dir

   or
           system "dir"

   prints a directory listing and then returns to `gnuplot`.

   Other examples of the former syntax:
            system "date"; set time; plot "a.dat"
            print=1; if (print) replot; set out; system "lpr x.ps"


File: gnuplot.info,  Node: splot,  Next: stats_(Statistical_Summary),  Prev: shell,  Up: Commands

3.27 splot
==========

`splot` is the command for drawing 3D plots (well, actually projections
on a 2D surface, but you knew that).  It can create a plot from
functions or data read from files in a manner very similar to the
`plot` command.  `splot` provides only a single x, y, and z axis; there
is no equivalent to the x2 and y2 secondary axes provided by `plot`.

   See the `plot` command for many options available in both 2D and 3D
plots.

   Syntax:
           splot {<ranges>}
                 {<iteration>}
                 <function> | "<datafile>" {datafile-modifiers}}
                 {<title-spec>} {with <style>}
                 {, {definitions{,}} <function> ...}

   where either a <function> or the name of a data file enclosed in
quotes is supplied.  The function can be a mathematical expression, or
a triple of mathematical expressions in parametric mode.

   By default `splot` draws the xy plane completely below the plotted
data.  The offset between the lowest ztic and the xy plane can be
changed by *note xyplane::.  The orientation of a `splot` projection is
controlled by *note view::.  See *note view:: and *note xyplane:: for
more information.

   The syntax for setting ranges on the `splot` command is the same as
for `plot`.  In non-parametric mode, the order in which ranges must be
given is *note xrange::, *note yrange::, and *note zrange::.  In
parametric mode, the order is *note urange::, *note vrange::, *note
xrange::, *note yrange::, and *note zrange::.

   The *note title:: option is the same as in `plot`.  The operation of
*note with:: is also the same as in `plot`, except that the plotting
styles available to `splot` are limited to `lines`, `points`, *note
linespoints::, *note dots::, and *note impulses::;  the error-bar
capabilities of `plot` are not available for `splot`.

   The *note datafile:: options have more differences.

   See also `show plot`.

* Menu:

* data-file::
* grid_data::
* splot_surfaces::


File: gnuplot.info,  Node: data-file,  Next: grid_data,  Prev: splot,  Up: splot

3.27.1 data-file
----------------

`Splot`, like `plot`, can display from a file.

   Syntax:
           splot '<file_name>' {binary <binary list>}
                               {{nonuniform} matrix}
                               {index <index list>}
                               {every <every list>}
                               {using <using list>}

   The special filenames `""` and `"-"` are permitted, as in `plot`.
See *note special-filenames::.

   In brief, *note binary:: and *note matrix:: indicate that the data
are in a special form, *note index:: selects which data sets in a
multi-data-set file are to be plotted, *note every:: specifies which
datalines (subsets) within a single data set are to be plotted, and
*note using:: determines how the columns within a single record are to
be interpreted.

   The options *note index:: and *note every:: behave the same way as
with `plot`;  *note using:: does so also, except that the *note using::
list must provide three entries instead of two.

   The `plot` options *note thru:: and *note smooth:: are not available
for `splot`, but *note cntrparam:: and *note dgrid3d:: provide limited
smoothing capabilities.

   Data file organization is essentially the same as for `plot`, except
that each point is an (x,y,z) triple.  If only a single value is
provided, it will be used for z, the datablock number will be used for
y, and the index of the data point in the datablock will be used for x.
If two or four values are provided, `gnuplot` uses the last value for
calculating the color in pm3d plots.  Three values are interpreted as
an (x,y,z) triple.  Additional values are generally used as errors,
which can be used by *note fit::.

   Single blank records separate datablocks in a `splot` datafile;
`splot` treats datablocks as the equivalent of function y-isolines.  No
line will join points separated by a blank record.  If all datablocks
contain the same number of points, `gnuplot` will draw cross-isolines
between datablocks, connecting corresponding points.  This is termed
"grid data", and is required for drawing a surface, for contouring
(*note contour::) and hidden-line removal (*note hidden3d::). See also
`splot grid_data`.

   It is no longer necessary to specify `parametric` mode for
three-column `splot`s.

* Menu:

* matrix::
* example_datafile_::


File: gnuplot.info,  Node: matrix,  Next: example_datafile_,  Prev: data-file,  Up: data-file

3.27.1.1 matrix
...............

Gnuplot can interpret matrix input in two different ways.  The first of
these assumes a uniform grid of x and y coordinates, and assigns each
value in the input matrix to one element of this uniform grid.  This is
the default for ascii data input, but not for binary input.  Example
commands for plotting uniform matrix data:
          splot 'file' matrix using 1:2:3          # ascii input
          splot 'file' binary general using 1:2:3  # binary input

   In a uniform grid matrix the z-values are read in a row at a time,
i. e.,
         z11 z12 z13 z14 ...
         z21 z22 z23 z24 ...
         z31 z32 z33 z34 ...

   and so forth.

   For ascii input, a blank line or comment line ends the matrix, and
starts a new surface mesh.  You can select among the meshes inside a
file by the *note index:: option to the `splot` command, as usual.  

   The second interpretation assumes a non-uniform grid with explicit x
and y coordinates. The first row of input data contains the y
coordinates; the first column of input data contains the x coordinates.
For binary input data, the first element of the first row must contain
the number of data columns. (This number is ignored for ascii input).
Both the coordinates and the data values in a binary input are treated
as single precision floats.  Example commands for plotting non-uniform
matrix data:
          splot 'file' nonuniform matrix using 1:2:3  # ascii input
          splot 'file' binary matrix using 1:2:3      # binary input

   Thus the data organization for non-uniform matrix input is

           <N+1>  <y0>   <y1>   <y2>  ...  <yN>
            <x0> <z0,0> <z0,1> <z0,2> ... <z0,N>
            <x1> <z1,0> <z1,1> <z1,2> ... <z1,N>
             :      :      :      :   ...    :

   which is then converted into triplets:
           <x0> <y0> <z0,0>
           <x0> <y1> <z0,1>
           <x0> <y2> <z0,2>
            :    :     :
           <x0> <yN> <z0,N>

           <x1> <y0> <z1,0>
           <x1> <y1> <z1,1>
            :    :     :

   These triplets are then converted into `gnuplot` iso-curves and then
`gnuplot` proceeds in the usual manner to do the rest of the plotting.

   A collection of matrix and vector manipulation routines (in C) is
provided in `binary.c`.  The routine to write binary data is

           int fwrite_matrix(file,m,nrl,nrl,ncl,nch,row_title,column_title)

   An example of using these routines is provided in the file
`bf_test.c`, which generates binary files for the demo file
`demo/binary.dem`.

   Usage in `plot`:
         plot `a.dat` matrix
         plot `a.dat` matrix using 1:3
         plot 'a.gpbin' {matrix} binary using 1:3

   will plot rows of the matrix, while using 2:3 will plot matrix
columns, and using 1:2 the point coordinates (rather useless). Applying
the *note every:: option you can specify explicit rows and columns.

   Example - rescale axes of a matrix in an ascii file:
         splot `a.dat` matrix using (1+$1):(1+$2*10):3

   Example - plot the 3rd row of a matrix in an ascii file:
         plot 'a.dat' matrix using 1:3 every 1:999:1:2

   (rows are enumerated from 0, thus 2 instead of 3).

   Gnuplot can read matrix binary files by use of the option *note
binary:: appearing without keyword qualifications unique to general
binary, i.e., *note array::, *note record::, `format`, or *note
filetype::.  Other general binary keywords for translation should also
apply to matrix binary.  (See *note general:: for more details.)


File: gnuplot.info,  Node: example_datafile_,  Prev: matrix,  Up: data-file

3.27.1.2 example datafile
.........................

A simple example of plotting a 3D data file is

           splot 'datafile.dat'

   where the file "datafile.dat" might contain:

           # The valley of the Gnu.
              0 0 10
              0 1 10
              0 2 10

              1 0 10
              1 1 5
              1 2 10

              2 0 10
              2 1 1
              2 2 10

              3 0 10
              3 1 0
              3 2 10

   Note that "datafile.dat" defines a 4 by 3 grid ( 4 rows of 3 points
each ).  Rows (datablocks) are separated by blank records.

   Note also that the x value is held constant within each dataline.
If you instead keep y constant, and plot with hidden-line removal
enabled, you will find that the surface is drawn 'inside-out'.

   Actually for grid data it is not necessary to keep the x values
constant within a datablock, nor is it necessary to keep the same
sequence of y values.  `gnuplot` requires only that the number of
points be the same for each datablock.  However since the surface mesh,
from which contours are derived, connects sequentially corresponding
points, the effect of an irregular grid on a surface plot is
unpredictable and should be examined on a case-by-case basis.


File: gnuplot.info,  Node: grid_data,  Next: splot_surfaces,  Prev: data-file,  Up: splot

3.27.2 grid data
----------------

The 3D routines are designed for points in a grid format, with one
sample, datapoint, at each mesh intersection; the datapoints may
originate from either evaluating a function, see *note isosamples::, or
reading a datafile, see *note datafile::.  The term "isoline" is
applied to the mesh lines for both functions and data.  Note that the
mesh need not be rectangular in x and y, as it may be parameterized in
u and v, see *note isosamples::.

   However, `gnuplot` does not require that format.  In the case of
functions, 'samples' need not be equal to 'isosamples', i.e., not every
x-isoline sample need intersect a y-isoline. In the case of data files,
if there are an equal number of scattered data points in each
datablock, then "isolines" will connect the points in a datablock, and
"cross-isolines" will connect the corresponding points in each
datablock to generate a "surface".  In either case, contour and
hidden3d modes may give different plots than if the points were in the
intended format.  Scattered data can be converted to a {different} grid
format with *note dgrid3d::.

   The contour code tests for z intensity along a line between a point
on a y-isoline and the corresponding point in the next y-isoline.  Thus
a `splot` contour of a surface with samples on the x-isolines that do
not coincide with a y-isoline intersection will ignore such samples.
Try:
            set xrange [-pi/2:pi/2]; set yrange [-pi/2:pi/2]
            set style function lp
            set contour
            set isosamples 10,10; set samples 10,10;
            splot cos(x)*cos(y)
            set samples 4,10; replot
            set samples 10,4; replot


File: gnuplot.info,  Node: splot_surfaces,  Prev: grid_data,  Up: splot

3.27.3 splot surfaces
---------------------

`splot` can display a surface as a collection of points, or by
connecting those points.  As with `plot`, the points may be read from a
data file or result from evaluation of a function at specified
intervals, see *note isosamples::.  The surface may be approximated by
connecting the points with straight line segments, see *note surface::,
in which case the surface can be made opaque with `set hidden3d.`  The
orientation from which the 3d surface is viewed can be changed with
*note view::.

   Additionally, for points in a grid format, `splot` can interpolate
points having a common amplitude (see *note contour::) and can then
connect those new points to display contour lines, either directly with
straight-line segments or smoothed lines (see *note cntrparam::).
Functions are already evaluated in a grid format, determined by *note
isosamples:: and *note samples::, while file data must either be in a
grid format, as described in *note data-file::, or be used to generate
a grid (see *note dgrid3d::).

   Contour lines may be displayed either on the surface or projected
onto the base.  The base projections of the contour lines may be
written to a file, and then read with `plot`, to take advantage of
`plot`'s additional formatting capabilities.


File: gnuplot.info,  Node: stats_(Statistical_Summary),  Next: system_,  Prev: splot,  Up: Commands

3.28 stats (Statistical Summary)
================================

Syntax:
          stats 'filename' [using N[:M]] [name 'prefix'] [[no]output]]

   This command prepares a statistical summary of the data in one or
two columns of a file. The using specifier is interpreted in the same
way as for plot commands. See `plot` for details on the *note index::,
*note every::, and *note using:: directives. Data points are filtered
against both xrange and yrange before analysis. See *note xrange::. The
summary is printed to the screen by default.  Output can be redirected
to a file by prior use of the command *note print::, or suppressed
altogether using the `nooutput` option.

   In addition to printed output, the program stores the individual
statistics into three sets of variables.  The first set of variables
reports how the data is laid out in the file:
          STATS_records           # total number of in-range data records
          STATS_outofrange        # number of records filtered out by range limits
          STATS_invalid           # number of invalid/incomplete/missing records
          STATS_blank             # number of blank lines in the file
          STATS_blocks            # number of indexable data blocks in the file

   The second set reports properties of the in-range data from a single
column.  If the corresponding axis is autoscaled (x-axis for the 1st
column, y-axis for the optional second column) then no range limits are
applied. If two columns are being analysed in a single `stats` command,
the the suffix "_x" or "_y" is appended to each variable name.  I.e.
STATS_min_x is the minimum value found in the first column, while
STATS_min_y is the minimum value found in the second column.
          STATS_min               # minimum value of in-range data points
          STATS_max               # maximum value of in-range data points
          STATS_index_min         # index i for which data[i] == STATS_min
          STATS_index_max         # index i for which data[i] == STATS_max
          STATS_lo_quartile       # value of the lower (1st) quartile boundary
          STATS_median            # median value
          STATS_up_quartile       # value of the upper (3rd) quartile boundary
          STATS_mean              # mean value of in-range data points
          STATS_stddev            # standard deviation of the in-range data points
          STATS_sum               # sum
          STATS_sumsq             # sum of squares

   The third set of variables is only relevant to analysis of two data
columns.
          STATS_correlation       # correlation coefficient between x and y values
          STATS_slope             # A corresponding to a linear fit y = Ax + B
          STATS_intercept         # B corresponding to a linear fit y = Ax + B
          STATS_sumxy             # sum of x*y
          STATS_pos_min_y         # x coordinate of a point with minimum y value
          STATS_pos_max_y         # x coordinate of a point with maximum y value

   It may be convenient to track the statistics from more than one file
at the same time. The `name` option causes the default prefix "STATS"
to be replaced by a user-specified string.  For example, the mean value
of column 2 data from two different files could be compared by
          stats "file1.dat" using 2 name "A"
          stats "file2.dat" using 2 name "B"
          if (A_mean < B_mean) {...}

   The index reported in STATS_index_xxx corresponds to the value of
pseudo-column 0 ($0) in plot commands.  I.e. the first point has index
0, the last point has index N-1.

   Data values are sorted to find the median and quartile boundaries.
If the total number of points N is odd, then the median value is taken
as the value of data point (N+1)/2. If N is even, then the median is
reported as the mean value of points N/2 and (N+2)/2. Equivalent
treatment is used for the quartile boundaries.

   For an example of using the `stats` command to help annotate a
subsequent plot, see stats.dem.
(http://www.gnuplot.info/demo/stats.html)

   The current implementation does not allow analysis if either the X
or Y axis is set to log-scaling.  This restriction may be removed in a
later version.


File: gnuplot.info,  Node: system_,  Next: test,  Prev: stats_(Statistical_Summary),  Up: Commands

3.29 system
===========

`system "command"` executes "command" using the standard shell. See
*note shell::.  If called as a function, `system("command")` returns
the resulting character stream from stdout as a string.  One optional
trailing newline is ignored.

   This can be used to import external functions into gnuplot scripts:

           f(x) = real(system(sprintf("somecommand %f", x)))


File: gnuplot.info,  Node: test,  Next: undefine,  Prev: system_,  Up: Commands

3.30 test
=========

This command graphically tests or presents terminal and palette
capabilities.

   Syntax:
           test {terminal | palette [rgb|rbg|grb|gbr|brg|bgr]}

   *note test:: or *note terminal:: creates a display of line and point
styles and other useful things appropriate for and supported by the
*note terminal:: you are just using.

   *note palette:: plots profiles of R(z),G(z),B(z), where 0<=z<=1.
These are the RGB components of the current color *note palette::. It
also plots the apparent net intensity as calculated using NTSC
coefficients to map RGB onto a grayscale.  The optional parameter, a
permutation of letters rgb, determines the sequence in which the r,g,b
profiles are drawn.


File: gnuplot.info,  Node: undefine,  Next: unset,  Prev: test,  Up: Commands

3.31 undefine
=============

Clear one or more previously defined user variables.  This is useful in
order to reset the state of a script containing an initialization test.

   A variable name can contain the wildcard character `*` as last
character. If the wildcard character is found, all variables with names
that begin with the prefix preceding the wildcard will be removed. This
is useful to remove several variables sharing a common prefix. Note
that the wildcard character is only allowed at the end of the variable
name! Specifying the wildcard character as sole argument to *note
undefine:: has no effect.

   Example:

           undefine foo foo1 foo2
           if (!exists("foo")) load "initialize.gp"

           bar = 1; bar1 = 2; bar2 = 3
           undefine bar*                 # removes all three variables


File: gnuplot.info,  Node: unset,  Next: update,  Prev: undefine,  Up: Commands

3.32 unset
==========

Options set using the `set` command may be returned to their default
state by the corresponding *note unset:: command.  The *note unset::
command may contain an optional iteration clause. See *note iteration::.

   Examples:
           set xtics mirror rotate by -45 0,10,100
           ...
           unset xtics

           # Unset labels numbered between 100 and 200
           unset for [i=100:200] label i


File: gnuplot.info,  Node: update,  Next: While,  Prev: unset,  Up: Commands

3.33 update
===========

This command writes the current values of the fit parameters into the
given file, formatted as an initial-value file (as described in the
*note fit::section).  This is useful for saving the current values for
later use or for restarting a converged or stopped fit.

   Syntax:
           update <filename> {<filename>}

   If a second filename is supplied, the updated values are written to
this file, and the original parameter file is left unmodified.

   Otherwise, if the file already exists, `gnuplot` first renames it by
appending `.old` and then opens a new file.  That is, "`update 'fred'`"
behaves the same as "`!rename fred fred.old; update 'fred.old' 'fred'`".
[On DOS and other systems that use the twelve-character "filename.ext"
naming convention, "ext" will be "`old`" and "filename" will be related
(hopefully recognizably) to the initial name.  Renaming is not done at
all on VMS systems, since they use file-versioning.]

   Please see *note fit:: for more information.


File: gnuplot.info,  Node: While,  Prev: update,  Up: Commands

3.34 While
==========

Syntax:
           while (<expr>) {
               <commands>
           }

   Execute a block of commands repeatedly so long as <expr> evaluates to
a non-zero value.  This command cannot be mixed with old-style
(un-bracketed) if/else statements.  See `if`.


File: gnuplot.info,  Node: Terminal_types,  Next: Bugs,  Prev: Commands,  Up: Top

4 Terminal types
****************

* Menu:

* complete_list_of_terminals::


File: gnuplot.info,  Node: complete_list_of_terminals,  Prev: Terminal_types,  Up: Terminal_types

4.1 complete list of terminals
==============================

Gnuplot supports a large number of output formats. These are selected by
choosing an appropriate terminal type, possibly with additional
modifying options. See *note terminal::.

   This document may describe terminal types that are not available to
you because they were not configured or installed on your system. To
see a list of terminals available on a particular gnuplot installation,
type 'set terminal' with no modifiers.  @c <3 - all terminal stuff is
pulled from the .trm files

* Menu:

* aed767::
* aifm::
* aqua::
* be::
* epscairo::
* canvas::
* cgi::
* cgm::
* context::
* corel::
* debug::
* svga::
* dumb::
* dxf::
* dxy800a::
* eepic::
* emf::
* emxvga::
* epson_180dpi::
* excl::
* fig::
* png_::
* ggi::
* gpic::
* grass::
* hp2623a::
* hp2648::
* hp500c::
* hpgl::
* hpljii::
* hppj::
* imagen::
* kyo::
* latex::
* linux::
* lua::
* macintosh::
* mf::
* mp::
* mif::
* next::
* Openstep_(next)::
* pbm::
* dospc::
* pdf::
* pstricks::
* qms::
* regis::
* sun::
* svg::
* tek410x::
* tek40::
* texdraw::
* tgif::
* tkcanvas::
* tpic::
* unixpc::
* vx384::
* vgagl::
* VWS::
* windows::
* wxt::
* x11::
* xlib::


File: gnuplot.info,  Node: aed767,  Next: aifm,  Prev: complete_list_of_terminals,  Up: complete_list_of_terminals

4.1.0.1 aed767
..............

The `aed512` and `aed767` terminal drivers support AED graphics
terminals.  The two drivers differ only in their horizontal ranges,
which are 512 and 768 pixels, respectively.  Their vertical range is
575 pixels.  There are no options for these drivers."


File: gnuplot.info,  Node: aifm,  Next: aqua,  Prev: aed767,  Up: complete_list_of_terminals

4.1.0.2 aifm
............

*note terminal::, originally written for Adobe Illustrator 3.0+.  Since
Adobe Illustrator understands PostScript level 1 commands directly, you
should use `set terminal post level1` instead.

   Syntax:
           set terminal aifm {color|monochrome} {"<fontname>"} {<fontsize>}


File: gnuplot.info,  Node: aqua,  Next: be,  Prev: aifm,  Up: complete_list_of_terminals

4.1.0.3 aqua
............

This terminal relies on AquaTerm.app for display on Mac OS X.

   Syntax:
           set terminal aqua {<n>} {title "<wintitle>"} {size <x> <y>}
                             {font "<fontname>{,<fontsize>}"}
                             {{no}enhanced} {solid|dashed} {dl <dashlength>}}

   where <n> is the number of the window to draw in (default is 0),
<wintitle> is the name shown in the title bar (default "Figure <n>"),
<x> <y> is the size of the plot (default is 846x594 pt = 11.75x8.25 in).

   Use <fontname> to specify the font (default is "Times-Roman"), and
<fontsize> to specify the font size (default is 14.0 pt).

   The aqua terminal supports enhanced text mode (see `enhanced`),
except for overprint. Font support is limited to the fonts available on
the system.  Character encoding can be selected by *note encoding:: and
currently supports iso_latin_1, iso_latin_2, cp1250, and UTF8 (default).

   Lines can be drawn either solid or dashed, (default is solid) and
the dash spacing can be modified by <dashlength> which is a multiplier
> 0.


File: gnuplot.info,  Node: be,  Next: epscairo,  Prev: aqua,  Up: complete_list_of_terminals

4.1.0.4 be
..........

The `be` terminal type is present if gnuplot is built for the `beos`
operating system and for use with X servers.  It is selected at program
startup if the `DISPLAY` environment variable is set, if the `TERM`
environment variable is set to `xterm`, or if the `-display` command
line option is used.

   Syntax:
               set terminal be {reset} {<n>}

   Multiple plot windows are supported: `set terminal be <n>` directs
the output to plot window number n.  If n>0, the terminal number will be
appended to the window title and the icon will be labeled `gplt <n>`.
The active window may distinguished by a change in cursor (from default
to crosshair.)

   Plot windows remain open even when the `gnuplot` driver is changed
to a different device.  A plot window can be closed by pressing the
letter q while that window has input focus, or by choosing `close` from
a window manager menu.  All plot windows can be closed by specifying
*note reset::, which actually terminates the subprocess which maintains
the windows (unless `-persist` was specified).

   Plot windows will automatically be closed at the end of the session
unless the `-persist` option was given.

   The size or aspect ratio of a plot may be changed by resizing the
`gnuplot` window.

   Linewidths and pointsizes may be changed from within `gnuplot` with
`set linestyle`.

   For terminal type `be`, `gnuplot` accepts (when initialized) the
standard X Toolkit options and resources such as geometry, font, and
name from the command line arguments or a configuration file.  See the
X(1) man page (or its equivalent) for a description of such options.

   A number of other `gnuplot` options are available for the `be`
terminal.  These may be specified either as command-line options when
`gnuplot` is invoked or as resources in the configuration file
".Xdefaults".  They are set upon initialization and cannot be altered
during a `gnuplot` session.

-- COMMAND-LINE_OPTIONS --

   In addition to the X Toolkit options, the following options may be
specified on the command line when starting `gnuplot` or as resources
in your ".Xdefaults" file:

      `-mono`        forces monochrome rendering on color displays.
      `-gray`        requests grayscale rendering on grayscale or color displays.
                             (Grayscale displays receive monochrome rendering by default.)
      `-clear`   requests that the window be cleared momentarily before a
                             new plot is displayed.
      `-raise`   raises plot window after each plot
      `-noraise` does not raise plot window after each plot
      `-persist` plots windows survive after main gnuplot program exits

   The options are shown above in their command-line syntax.  When
entered as resources in ".Xdefaults", they require a different syntax.

   Example:
               gnuplot*gray: on

   `gnuplot` also provides a command line option (`-pointsize <v>`) and
a resource, `gnuplot*pointsize: <v>`, to control the size of points
plotted with the `points` plotting style.  The value `v` is a real
number (greater than 0 and less than or equal to ten) used as a scaling
factor for point sizes.  For example, `-pointsize 2` uses points twice
the default size, and `-pointsize 0.5` uses points half the normal size.

-- MONOCHROME_OPTIONS --

   For monochrome displays, `gnuplot` does not honor foreground or
background colors.  The default is black-on-white.  `-rv` or
`gnuplot*reverseVideo: on` requests white-on-black.

-- COLOR_RESOURCES --

   For color displays, `gnuplot` honors the following resources (shown
here with their default values) or the greyscale resources.  The values
may be color names as listed in the BE rgb.txt file on your system,
hexadecimal RGB color specifications (see BE documentation), or a color
name followed by a comma and an `intensity` value from 0 to 1.  For
example, `blue, 0.5` means a half intensity blue.

      gnuplot*background:  white
      gnuplot*textColor:   black
      gnuplot*borderColor: black
      gnuplot*axisColor:   black
      gnuplot*line1Color:  red
      gnuplot*line2Color:  green
      gnuplot*line3Color:  blue
      gnuplot*line4Color:  magenta
      gnuplot*line5Color:  cyan
      gnuplot*line6Color:  sienna
      gnuplot*line7Color:  orange
      gnuplot*line8Color:  coral

   The command-line syntax for these is, for example,

   Example:
               gnuplot -background coral

-- GRAYSCALE_RESOURCES --

   When `-gray` is selected, `gnuplot` honors the following resources
for grayscale or color displays (shown here with their default values).
Note that the default background is black.

      gnuplot*background: black
      gnuplot*textGray:   white
      gnuplot*borderGray: gray50
      gnuplot*axisGray:   gray50
      gnuplot*line1Gray:  gray100
      gnuplot*line2Gray:  gray60
      gnuplot*line3Gray:  gray80
      gnuplot*line4Gray:  gray40
      gnuplot*line5Gray:  gray90
      gnuplot*line6Gray:  gray50
      gnuplot*line7Gray:  gray70
      gnuplot*line8Gray:  gray30

-- LINE_RESOURCES --

   `gnuplot` honors the following resources for setting the width (in
pixels) of plot lines (shown here with their default values.)  0 or 1
means a minimal width line of 1 pixel width.  A value of 2 or 3 may
improve the appearance of some plots.

      gnuplot*borderWidth: 2
      gnuplot*axisWidth:   0
      gnuplot*line1Width:  0
      gnuplot*line2Width:  0
      gnuplot*line3Width:  0
      gnuplot*line4Width:  0
      gnuplot*line5Width:  0
      gnuplot*line6Width:  0
      gnuplot*line7Width:  0
      gnuplot*line8Width:  0

   `gnuplot` honors the following resources for setting the dash style
used for plotting lines.  0 means a solid line.  A two-digit number
`jk` (`j` and `k` are >= 1  and <= 9) means a dashed line with a
repeated pattern of `j` pixels on followed by `k` pixels off.  For
example, '16' is a "dotted" line with one pixel on followed by six
pixels off.  More elaborate on/off patterns can be specified with a
four-digit value.  For example, '4441' is four on, four off, four on,
one off.  The default values shown below are for monochrome displays or
monochrome rendering on color or grayscale displays.  For color
displays, the default for each is 0 (solid line) except for
`axisDashes` which defaults to a '16' dotted line.

      gnuplot*borderDashes:   0
      gnuplot*axisDashes:        16
      gnuplot*line1Dashes:        0
      gnuplot*line2Dashes:   42
      gnuplot*line3Dashes:   13
      gnuplot*line4Dashes:   44
      gnuplot*line5Dashes:   15
      gnuplot*line6Dashes: 4441
      gnuplot*line7Dashes:   42
      gnuplot*line8Dashes:   13


File: gnuplot.info,  Node: epscairo,  Next: canvas,  Prev: be,  Up: complete_list_of_terminals

4.1.0.5 epscairo
................

The `epscairo` terminal device generates encapsulated PostScript
(*.eps) using the cairo and pango support libraries.  cairo verion >=
1.6 is required.

   Please read the help for the `pdfcairo` terminal."


File: gnuplot.info,  Node: canvas,  Next: cgi,  Prev: epscairo,  Up: complete_list_of_terminals

4.1.0.6 canvas
..............

The `canvas` terminal creates a set of javascript commands that draw
onto the HTML5 canvas element.  Syntax:
           set terminal canvas {size <xsize>, <ysize>} {background <rgb_color>}
                               {font {<fontname>}{,<fontsize>}} | {fsize <fontsize>}
                               {{no}enhanced} {linewidth <lw>}
                               {rounded | butt}
                               {solid | dashed {dashlength <dl>}}
                               {standalone {mousing} | name '<funcname>'}
                               {jsdir 'URL/for/javascripts'}
                               {title '<some string>'}

   where <xsize> and <ysize> set the size of the plot area in pixels.
The default size in standalone mode is 600 by 400 pixels.  The default
font size is 10.

   NB: Only one font is available, the ascii portion of Hershey simplex
Roman provided in the file canvastext.js. You can replace this with the
file canvasmath.js, which contains also UTF-8 encoded Hershey simplex
Greek and math symbols. For consistency with other terminals, it is
also possible to use `font "name,size"`. Currently the font `name` is
ignored, but browser support for named fonts is likely to arrive
eventually.

   The default `standalone` mode creates an html page containing
javascript code that renders the plot using the HTML 5 canvas element.
The html page links to two required javascript files 'canvastext.js'
and 'gnuplot_common.js'.  An additional file 'gnuplot_dashedlines.js'
is needed to support dashed lines.  By default these point to local
files, on unix-like systems usually in directory
/usr/local/share/gnuplot/<version>/js.  See installation notes for
other platforms. You can change this by using the `jsdir` option to
specify either a different local directory or a general URL.  The
latter is usually appropriate if the plot is exported for viewing on
remote client machines.

   All plots produced by the canvas terminal are mouseable.  The
additional keyword `mousing` causes the `standalone` mode to add a
mouse-tracking box underneath the plot. It also adds a link to a
javascript file 'gnuplot_mouse.js' and to a stylesheet for the mouse
box 'gnuplot_mouse.css' in the same local or URL directory as
'canvastext.js'.

   The `name` option creates a file containing only javascript. Both the
javascript function it contains and the id of the canvas element that it
draws onto are taken from the following string parameter.  The commands
           set term canvas name 'fishplot'
           set output 'fishplot.js'

   will create a file containing a javascript function fishplot() that
will draw onto a canvas with id=fishplot.  An html page that invokes
this javascript function must also load the canvastext.js function as
described above.  A minimal html file to wrap the fishplot created
above might be:

           <html>
           <head>
               <script src="canvastext.js"></script>
               <script src="gnuplot_common.js"></script>
           </head>
           <body onload="fishplot();">
               <script src="fishplot.js"></script>
               <canvas id="fishplot" width=600 height=400>
                   <div id="err_msg">No support for HTML 5 canvas element</div>
               </canvas>
           </body>
           </html>

   The individual plots drawn on this canvas will have names
fishplot_plot_1, fishplot_plot_2, and so on. These can be referenced by
external javascript routines, for example
gnuplot.toggle_visibility("fishplot_plot_2").


File: gnuplot.info,  Node: cgi,  Next: cgm,  Prev: canvas,  Up: complete_list_of_terminals

4.1.0.7 cgi
...........

The `cgi` and `hcgi` terminal drivers support SCO CGI drivers.  `hcgi`
is for printers; the environment variable CGIPRNT must be set.  `cgi`
may be used for either a display or hardcopy; the environment variable
CGIDISP is checked, first, then CGIPRNT.  These terminals have no
options."


File: gnuplot.info,  Node: cgm,  Next: context,  Prev: cgi,  Up: complete_list_of_terminals

4.1.0.8 cgm
...........

The `cgm` terminal generates a Computer Graphics Metafile, Version 1.
This file format is a subset of the ANSI X3.122-1986 standard entitled
"Computer Graphics - Metafile for the Storage and Transfer of Picture
Description Information".

   Syntax:
           set terminal cgm {color | monochrome} {solid | dashed} {{no}rotate}
                            {<mode>} {width <plot_width>} {linewidth <line_width>}
                            {font "<fontname>,<fontsize>"}
                            {background <rgb_color>}
       [deprecated]         {<color0> <color1> <color2> ...}

   `solid` draws all curves with solid lines, overriding any dashed
patterns; <mode> is `landscape`, `portrait`, or `default`; <plot_width>
is the assumed width of the plot in points; <line_width> is the line
width in points (default 1); <fontname> is the name of a font (see list
of fonts below) <fontsize> is the size of the font in points (default
12).

   The first six options can be in any order.  Selecting `default` sets
all options to their default values.

   The mechanism of setting line colors in the `set term` command is
deprecated.  Instead you should set the background using a separate
keyword and set the line colors using `set linetype`.  The deprecated
mechanism accepted colors of the form 'xrrggbb', where x is the literal
character 'x' and 'rrggbb' are the red, green and blue components in
hex. The first color was used for the background, subsequent colors are
assigned to successive line types.

   Examples:
           set terminal cgm landscape color rotate dashed width 432 \\
                          linewidth 1  'Helvetica Bold' 12       # defaults
           set terminal cgm linewidth 2  14  # wider lines & larger font
           set terminal cgm portrait "Times Italic" 12
           set terminal cgm color solid      # no pesky dashes!

-- CGM FONT --

   The first part of a Computer Graphics Metafile, the metafile
description, includes a font table.  In the picture body, a font is
designated by an index into this table.  By default, this terminal
generates a table with the following 35 fonts, plus six more with
`italic` replaced by `oblique`, or vice-versa (since at least the
Microsoft Office and Corel Draw CGM import filters treat `italic` and
`oblique` as equivalent):

           Helvetica
           Helvetica Bold
           Helvetica Oblique
           Helvetica Bold Oblique
           Times Roman
           Times Bold
           Times Italic
           Times Bold Italic
           Courier
           Courier Bold
           Courier Oblique
           Courier Bold Oblique
           Symbol
           Hershey/Cartographic_Roman
           Hershey/Cartographic_Greek
           Hershey/Simplex_Roman
           Hershey/Simplex_Greek
           Hershey/Simplex_Script
           Hershey/Complex_Roman
           Hershey/Complex_Greek
           Hershey/Complex_Script
           Hershey/Complex_Italic
           Hershey/Complex_Cyrillic
           Hershey/Duplex_Roman
           Hershey/Triplex_Roman
           Hershey/Triplex_Italic
           Hershey/Gothic_German
           Hershey/Gothic_English
           Hershey/Gothic_Italian
           Hershey/Symbol_Set_1
           Hershey/Symbol_Set_2
           Hershey/Symbol_Math
           ZapfDingbats
           Script
           15

   The first thirteen of these fonts are required for WebCGM.  The
Microsoft Office CGM import filter implements the 13 standard fonts
listed above, and also 'ZapfDingbats' and 'Script'.  However, the
script font may only be accessed under the name '15'.  For more on
Microsoft import filter font substitutions, check its help file which
you may find here:
       C:\\Program Files\\Microsoft Office\\Office\\Cgmimp32.hlp

   and/or its configuration file, which you may find here:
       C:\\Program Files\\Common Files\\Microsoft Shared\\Grphflt\\Cgmimp32.cfg

   In the `set term` command, you may specify a font name which does not
appear in the default font table.  In that case, a new font table is
constructed with the specified font as its first entry. You must ensure
that the spelling, capitalization, and spacing of the name are
appropriate for the application that will read the CGM file.  (Gnuplot
and any MIL-D-28003A compliant application ignore case in font names.)
If you need to add several new fonts, use several `set term` commands.

   Example:
           set terminal cgm 'Old English'
           set terminal cgm 'Tengwar'
           set terminal cgm 'Arabic'
           set output 'myfile.cgm'
           plot ...
           set output

   You cannot introduce a new font in a `set label` command.

-- CGM FONTSIZE --

   Fonts are scaled assuming the page is 6 inches wide.  If the *note
size:: command is used to change the aspect ratio of the page or the
CGM file is converted to a different width, the resulting font sizes
will be scaled up or down accordingly.  To change the assumed width,
use the `width` option.

-- CGM LINEWIDTH --

   The `linewidth` option sets the width of lines in pt.  The default
width is 1 pt.  Scaling is affected by the actual width of the page, as
discussed under the `fontsize` and `width` options.

-- CGM ROTATE --

   The `norotate` option may be used to disable text rotation.  For
example, the CGM input filter for Word for Windows 6.0c can accept
rotated text, but the DRAW editor within Word cannot.  If you edit a
graph (for example, to label a curve), all rotated text is restored to
horizontal.  The Y axis label will then extend beyond the clip boundary.
With `norotate`, the Y axis label starts in a less attractive location,
but the page can be edited without damage.  The `rotate` option confirms
the default behavior.

-- CGM SOLID --

   The `solid` option may be used to disable dashed line styles in the
plots.  This is useful when color is enabled and the dashing of the
lines detracts from the appearance of the plot. The `dashed` option
confirms the default behavior, which gives a different dash pattern to
each line type.

-- CGM SIZE --

   Default size of a CGM plot is 32599 units wide and 23457 units high
for landscape, or 23457 units wide by 32599 units high for portrait.

-- CGM WIDTH --

   All distances in the CGM file are in abstract units.  The application
that reads the file determines the size of the final plot.  By default,
the width of the final plot is assumed to be 6 inches (15.24 cm).  This
distance is used to calculate the correct font size, and may be changed
with the `width` option.  The keyword should be followed by the width in
points.  (Here, a point is 1/72 inch, as in PostScript.  This unit is
known as a "big point" in TeX.)  Gnuplot `expressions` can be used to
convert from other units.

   Example:
           set terminal cgm width 432            # default
           set terminal cgm width 6*72           # same as above
           set terminal cgm width 10/2.54*72     # 10 cm wide

-- CGM NOFONTLIST --

   The default font table includes the fonts recommended for WebCGM,
which are compatible with the Computer Graphics Metafile input filter
for Microsoft Office and Corel Draw.  Another application might use
different fonts and/or different font names, which may not be
documented.  The `nofontlist` (synonym `winword6`) option deletes the
font table from the CGM file.  In this case, the reading application
should use a default table.  Gnuplot will still use its own default
font table to select font indices.  Thus, 'Helvetica' will give you an
index of 1, which should get you the first entry in your application's
default font table. 'Helvetica Bold' will give you its second entry,
etc.


File: gnuplot.info,  Node: context,  Next: corel,  Prev: cgm,  Up: complete_list_of_terminals

4.1.0.9 context
...............

ConTeXt is a macro package for TeX, highly integrated with Metapost
(for drawing figures) and intended for creation of high-quality PDF
documents.  The terminal outputs Metafun source, which can be edited
manually, but you should be able to configure most things from outside.

   For an average user of ConTeXt + gnuplot module it's recommended to
refer to `Using ConTeXt` rather than reading this page or to read the
manual of the gnuplot module for ConTeXt.

   The `context` terminal supports the following options:

   Syntax:
          set term context {default}
                  {defaultsize | size <scale> | size <xsize>{in|cm}, <ysize>{in|cm}}
                  {input | standalone}
                  {timestamp | notimestamp}
                  {noheader | header "<header>"}
                  {color | colour | monochrome}
                  {rounded | mitered | beveled} {round | butt | squared}
                  {dashed | solid} {dashlength | dl <dl>}
                  {linewidth | lw <lw>}
                  {fontscale <fontscale>}
                  {mppoints | texpoints}
                  {inlineimages | externalimages}
                  {defaultfont | font "{<fontname>}{,<fontsize>}"}

   In non-standalone (`input`) graphic only parameters *note size:: to
select graphic size, `fontscale` to scale all the labels for a factor
<fontscale> and font size, make sense, the rest is silently ignored and
should be configured in the .tex file which inputs the graphic.  It's
highly recommended to set the proper fontsize if document font differs
from 12pt, so that gnuplot will know how much space to reserve for
labels.

   `default` resets all the options to their default values.

   `defaultsize` sets the plot size to 5in,3in.  *note size:: <scale>
sets the plot size to <scale> times <default value>.  If two arguments
are given (separated with ','), the first one sets the horizontal size
and the second one the vertical size.  Size may be given without units
(in which case it means relative to the default value), with inches
('in') or centimeters ('cm').

   `input` (default) creates a graphic that can be included into
another ConTeXt document.  `standalone` adds some lines, so that the
document might be compiled as-is.  You might also want to add `header`
in that case.

   Use `header` for any additional settings/definitions/macros that you
might want to include in a standalone graphic. `noheader` is the
default.

   `notimestamp` prevents printing creation time in comments (if
version control is used, one may prefer not to commit new version when
only date changes).

   `color` to make color plots is the default, but `monochrome` doesn't
do anything special yet.  If you have any good ideas how the behaviour
should differ to suit the monochrome printers better, your suggestions
are welcome.

   `rounded` (default), `mitered` and `beveled` control the shape of
line joins.  `round` (default), `butt` and `squared` control the shape
of line caps.  See PostScript or PDF Reference Manual for explanation.
For wild-behaving functions and thick lines it is better to use
`rounded` and `round` to prevent sharp corners in line joins.  (Some
general support for this should be added to Gnuplot, so that the same
options could be set for each line (style) separately).

   `dashed` (default) uses different dash patterns for different line
types, `solid` draws all plots with solid lines.

   `dashlength` or `dl` scales the length of the dashed-line segments
by <dl>.  `linewidth` or `lw` scales all linewidths by <lw>.  (lw 1
stands for 0.5bp, which is the default line width when drawing with
Metapost.)  `fontscale` scales text labels for factor <fontscale>
relative to default document font.

   `mppoints` uses predefined point shapes, drawn in Metapost.
`texpoints` uses easily configurable set of symbols, defined with
ConTeXt in the following way:
          \\defineconversion[my own points][+,{\\ss x},\\mathematics{\\circ}]
          \\setupGNUPLOTterminal[context][points=tex,pointset=my own points]

   `inlineimages` writes binary images to a string and only works in
ConTeXt MKIV.  `externalimages` writes PNG files to disk and also works
with ConTeXt MKII.  Gnuplot needs to have support for PNG images built
in for this to work.

   With `font` you can set font name and size in standalone graphics.
In non-standalone (`input`) mode only the font size is important to
reserve enough space for text labels.  The command
          set term context font "myfont,ss,10"

   will result in
          \\setupbodyfont[myfont,ss,10pt]

   If you additionaly set `fontscale` to 0.8 for example, then the
resulting font will be 8pt big and
          set label ... font "myfont,12"

   will come out as 9.6pt.

   It is your own responsibility to provide proper typescripts (and
header), otherwise switching the font will have no effect.  For a
standard font in ConTeXt MKII (pdfTeX) you could use:
          set terminal context standalone header '\\usetypescript[iwona][ec]' \\
              font "iwona,ss,11"

   Please take a look into ConTeXt documentation, wiki or mailing list
(archives) for any up-to-date information about font usage.

   Examples:
          set terminal context size 10cm, 5cm     # 10cm, 5cm
          set terminal context size 4in, 3in      # 4in, 3in

   For standalone (whole-page) plots with labels in UTF-8 encoding:
          set terminal context standalone header '\\enableregime[utf-8]'

   , /* TODO: LaTeX formatting */

-- REQUIREMENTS --

   You need gnuplot module for ConTeXt
http://ctan.org/pkg/context-gnuplot
(http://ctan.org/pkg/context-gnuplot) and a recent version of ConTeXt.
If you want to call gnuplot on-the-fly, you also need write18 enabled.
In most TeX distributions this can be set with shell_escape=t in
texmf.cnf.

   See http://wiki.contextgarden.net/Gnuplot
(http://wiki.contextgarden.net/Gnuplot) for details about this terminal
and for more exhaustive help & examples.

-- CALLING GNUPLOT FROM CONTEXT --

   The easiest way to make plots in ConTeXt documents is
          \\usemodule[gnuplot]
          \\starttext
          \\title{How to draw nice plots with {\\sc gnuplot}?}
          \\startGNUPLOTscript[sin]
          set format y "%.1f"
          plot sin(x) t '$\\sin(x)$'
          \\stopGNUPLOTscript
          \\useGNUPLOTgraphic[sin]
          \\stoptext

   This will run gnuplot automatically and include the resulting figure
in the document."


File: gnuplot.info,  Node: corel,  Next: debug,  Prev: context,  Up: complete_list_of_terminals

4.1.0.10 corel
..............

The `corel` terminal driver supports CorelDraw.

   Syntax:
           set terminal corel {  default
                               | {monochrome | color
                                    {"<font>" {<fontsize>
                                       {<xsize> <ysize> {<linewidth> }}}}}

   where the fontsize and linewidth are specified in points and the
sizes in inches.  The defaults are monochrome, "SwitzerlandLight", 22,
8.2, 10 and 1.2."


File: gnuplot.info,  Node: debug,  Next: svga,  Prev: corel,  Up: complete_list_of_terminals

4.1.0.11 debug
..............

This terminal is provided to allow for the debugging of `gnuplot`.  It
is likely to be of use only for users who are modifying the source
code."


File: gnuplot.info,  Node: svga,  Next: dumb,  Prev: debug,  Up: complete_list_of_terminals

4.1.0.12 svga
.............

The `svga` terminal driver supports PCs with SVGA graphics.  It can
only be used if it is compiled with DJGPP.  Its only option is the font.

   Syntax:
           set terminal svga {"<fontname>"}"


File: gnuplot.info,  Node: dumb,  Next: dxf,  Prev: svga,  Up: complete_list_of_terminals

4.1.0.13 dumb
.............

The `dumb` terminal driver plots into a text block using ascii
characters.  It has an optional size specification and a trailing
linefeed flag.

   Syntax:
           set terminal dumb {size <xchars>,<ychars>} {[no]feed}
                             {[no]enhanced}

   where <xchars> and <ychars> set the size of the text block. The
default is 79 by 24. The last newline is printed only if `feed` is
enabled.

   Example:
           set term dumb size 60,15
           plot [-5:6.5] sin(x) with impulse

                1 +-------------------------------------------------+
              0.8 +|||++                   ++||||++   sin(x) +----+ |
              0.6 +|||||+                 ++|||||||+                |
              0.4 +||||||+               ++|||||||||+               |
              0.2 +|||||||+             ++|||||||||||+             +|
                0 ++++++++++++++++++++++++++++++++++++++++++++++++++|
             -0.2 +        +|||||||||||+              +|||||||||||+ |
             -0.4 +         +|||||||||+                +|||||||||+  |
             -0.6 +          +|||||||+                  +|||||||+   |
             -0.8 +   +       ++||||+   +       +        ++||||+  + |
               -1 +---+--------+--------+-------+--------+--------+-+
                     -4       -2        0       2        4        6  "


File: gnuplot.info,  Node: dxf,  Next: dxy800a,  Prev: dumb,  Up: complete_list_of_terminals

4.1.0.14 dxf
............

The `dxf` terminal driver creates pictures that can be imported into
AutoCad (Release 10.x).  It has no options of its own, but some
features of its plots may be modified by other means.  The default size
is 120x80 AutoCad units, which can be changed by *note size::.  `dxf`
uses seven colors (white, red, yellow, green, cyan, blue and magenta),
which can be changed only by modifying the source file.  If a
black-and-white plotting device is used, the colors are mapped to
differing line thicknesses.  See the description of the AutoCad
print/plot command."


File: gnuplot.info,  Node: dxy800a,  Next: eepic,  Prev: dxf,  Up: complete_list_of_terminals

4.1.0.15 dxy800a
................

This terminal driver supports the Roland DXY800A plotter.  It has no
options."


File: gnuplot.info,  Node: eepic,  Next: emf,  Prev: dxy800a,  Up: complete_list_of_terminals

4.1.0.16 eepic
..............

The `eepic` terminal driver supports the extended LaTeX picture
environment.  It is an alternative to the `latex` driver.

   The output of this terminal is intended for use with the "eepic.sty"
macro package for LaTeX.  To use it, you need "eepic.sty", "epic.sty"
and a printer driver that supports the "tpic" \\specials.  If your
printer driver doesn't support those \\specials, "eepicemu.sty" will
enable you to use some of them.  dvips and dvipdfm do support the
"tpic" \\specials.

   Syntax:
        set terminal eepic {default} {color|dashed} {rotate} {size XX,YY}
                           {small|tiny|<fontsize>}

   Options: You can give options in any order you wish.  'color' causes
gnuplot to produce \\color{...} commands so that the graphs are
colored. Using this option, you must include \\usepackage{color} in the
preambel of your latex document.  'dashed' will allow dashed line
types; without this option, only solid lines with varying thickness
will be used.  'dashed' and 'color' are mutually exclusive; if 'color'
is specified, then 'dashed' will be ignored.  'rotate' will enable true
rotated text (by 90 degrees). Otherwise, rotated text will be typeset
with letters stacked above each other. If you use this option you must
include \\usepackage{graphicx} in the preamble.  'small' will use
\\scriptsize symbols as point markers (Probably does not work with TeX,
only LaTeX2e). Default is to use the default math size.  'tiny' uses
\\scriptscriptstyle symbols.  'default' resets all options to their
defaults = no color, no dashed lines, pseudo-rotated (stacked) text,
large point symbols.  <fontsize> is a number which specifies the font
size inside the picture environment; the unit is pt (points), i.e., 10
pt equals approx. 3.5 mm.  If fontsize is not specified, then all text
inside the picture will be set in \\footnotesize.

   Notes: Remember to escape the # character (or other chars meaningful
to (La-)TeX) by \\\\ (2 backslashes).  It seems that dashed lines
become solid lines when the vertices of a plot are too close. (I do not
know if that is a general problem with the tpic specials, or if it is
caused by a bug in eepic.sty or dvips/dvipdfm.)  The default size of an
eepic plot is 5x3 inches. You can change this using the *note size::
terminal option.  Points, among other things, are drawn using the LaTeX
commands "\\Diamond", "\\Box", etc.  These commands no longer belong to
the LaTeX2e core; they are included in the latexsym package, which is
part of the base distribution and thus part of any LaTeX
implementation. Please do not forget to use this package.  Instead of
latexsym, you can also include the amssymb package.  All drivers for
LaTeX offer a special way of controlling text positioning: If any text
string begins with '{', you also need to include a '}' at the end of
the text, and the whole text will be centered both horizontally and
vertically.  If the text string begins with '[', you need to follow
this with a position specification (up to two out of t,b,l,r), ']{',
the text itself, and finally '}'.  The text itself may be anything
LaTeX can typeset as an LR-box.  '\\rule{}{}'s may help for best
positioning.

   Examples: set term eepic
       output graphs as eepic macros inside a picture environment;
       \\input the resulting file in your LaTeX document.

   set term eepic color tiny rotate 8
       eepic macros with \\color macros, \\scripscriptsize point markers,
       true rotated text, and all text set with 8pt.

   About label positioning: Use gnuplot defaults (mostly sensible, but
sometimes not really best):
            set title '\\LaTeX\\ -- $ \\gamma $'

   Force centering both horizontally and vertically:
            set label '{\\LaTeX\\ -- $ \\gamma $}' at 0,0

   Specify own positioning (top here):
            set xlabel '[t]{\\LaTeX\\ -- $ \\gamma $}'

   The other label - account for long ticlabels:
            set ylabel '[r]{\\LaTeX\\ -- $ \\gamma $\\rule{7mm}{0pt}}'"


File: gnuplot.info,  Node: emf,  Next: emxvga,  Prev: eepic,  Up: complete_list_of_terminals

4.1.0.17 emf
............

The `emf` terminal generates an Enhanced Metafile Format file.  This
file format is recognized by many Windows applications.

   Syntax:
           set terminal emf {color | monochrome} {solid | dashed}
                            {enhanced {noproportional}}
                            {rounded | butt}
                            {linewidth <LW>} {dashlength <DL>}
                            {size XX,YY} {background <rgb_color>}
                            {font "<fontname>{,<fontsize>}"}
                            {fontscale <scale>}

   In `monochrome` mode successive line types cycle through dash
patterns.  In `color` mode successive line types use successive colors,
and only after all 8 default colors are exhausted is the dash pattern
incremented.  `solid` draws all curves with solid lines, overriding any
dashed patterns; `linewidth <factor>` multiplies all line widths by
this factor.  `dashlength <factor>` is useful for thick lines.
<fontname> is the name of a font; and `<fontsize>` is the size of the
font in points.

   The nominal size of the output image defaults to 1024x768 in
arbitrary units. You may specify a different nominal size using the
*note size:: option.

   Enhanced text mode tries to approximate proportional character
spacing.  If you are using a monospaced font, or don't like the
approximation, you can turn off this correction using the
`noproportional` option.

   The default settings are `color solid font "Arial,12" size 1024,768`
Selecting `default` sets all options to their default values.

   Examples:
           set terminal emf 'Times Roman Italic, 12'
           set terminal emf dashed    # otherwise all lines are solid"


File: gnuplot.info,  Node: emxvga,  Next: epson_180dpi,  Prev: emf,  Up: complete_list_of_terminals

4.1.0.18 emxvga
...............

The `emxvga`, `emxvesa` and `vgal` terminal drivers support PCs with
SVGA, vesa SVGA and VGA graphics boards, respectively.  They are
intended to be compiled with "emx-gcc" under either DOS or OS/2.  They
also need VESA and SVGAKIT maintained by Johannes Martin
(JMARTIN@GOOFY.ZDV.UNI-MAINZ.DE) with additions by David J. Liu
(liu@phri.nyu.edu).

   Syntax:
           set terminal emxvga
           set terminal emxvesa {vesa-mode}
           set terminal vgal

   The only option is the vesa mode for `emxvesa`, which defaults to
G640x480x256."


File: gnuplot.info,  Node: epson_180dpi,  Next: excl,  Prev: emxvga,  Up: complete_list_of_terminals

4.1.0.19 epson_180dpi
.....................

This driver supports a family of Epson printers and derivatives.

   `epson_180dpi` and `epson_60dpi` are drivers for Epson LQ-style
24-pin printers with resolutions of 180 and 60 dots per inch,
respectively.

   `epson_lx800` is a generic 9-pin driver appropriate for printers
like the Epson LX-800, the Star NL-10 and NX-1000, the PROPRINTER, and
so forth.

   `nec_cp6` is generic 24-pin driver that can be used for printers
like the NEC CP6 and the Epson LQ-800.

   The `okidata` driver supports the 9-pin OKIDATA 320/321 Standard
printers.

   The `starc` driver is for the Star Color Printer.

   The `tandy_60dpi` driver is for the Tandy DMP-130 series of 9-pin,
60-dpi printers.

   The `dpu414` driver is for the Seiko DPU-414 thermal printer.

   `nec_cp6` has the options:

   Syntax:
           set terminal nec_cp6 {monochrome | colour | draft}

   which defaults to monochrome.

   `dpu414` has the options:

   Syntax:
           set terminal dpu414 {small | medium | large} {normal | draft}

   which defaults to medium (=font size) and normal.  Preferred
combinations are `medium normal` and `small draft`.

   With each of these drivers, a binary copy is required on a PC to
print.  Do not use *note print::--use instead `copy file /b lpt1:`.


File: gnuplot.info,  Node: excl,  Next: fig,  Prev: epson_180dpi,  Up: complete_list_of_terminals

4.1.0.20 excl
.............

The `excl` terminal driver supports Talaris printers such as the EXCL
Laser printer and the 1590.  It has no options."


File: gnuplot.info,  Node: fig,  Next: png_,  Prev: excl,  Up: complete_list_of_terminals

4.1.0.21 fig
............

The `fig` terminal device generates output in the Fig graphics language.

   Syntax:
           set terminal fig {monochrome | color}
                            {landscape | portrait}
                            {small | big | size <xsize> <ysize>}
                            {metric | inches}
                            {pointsmax <max_points>}
                            {solid | dashed}
                            {font "<fontname>{,<fontsize>}"}
                            {textnormal | {textspecial texthidden textrigid}}
                            {{thickness|linewidth} <units>}
                            {depth <layer>}
                            {version <number>}

   `monochrome` and `color` determine whether the picture is
black-and-white or `color`.  `small` and `big` produce a 5x3 or 8x5
inch graph in the default `landscape` mode and 3x5 or 5x8 inches in
`portrait` mode.  *note size:: sets (overrides) the size of the drawing
area to <xsize>*<ysize> in units of inches or centimeters depending on
the `inches` or `metric` setting in effect.  The latter settings is
also used as default units for editing with "xfig".

   `pointsmax <max_points>` sets the maximum number of points per
polyline.

   `solid` inhibits automatic usage of `dash`ed lines when solid
linestyles are used up, which otherwise occurs.

   `font` sets the text font face to <fontname> and its size to
<fontsize> points. `textnormal` resets the text flags and selects
postscript fonts, `textspecial` sets the text flags for LaTeX specials,
`texthidden` sets the hidden flag and `textrigid` the rigid flag.

   `depth` sets the default depth layer for all lines and text.  The
default depth is 10 to leave room for adding material with "xfig" on
top of the plot.

   *note version:: sets the format version of the generated fig output.
Currently only versions 3.1 and 3.2 are supported.

   `thickness` sets the default line thickness, which is 1 if not
specified.  Overriding the thickness can be achieved by adding a
multiple of 100 to the `linetype` value for a `plot` command.  In a
similar way the `depth` of plot elements (with respect to the default
depth) can be controlled by adding a multiple of 1000 to <linetype>.
The depth is then <layer> + <linetype>/1000 and the thickness is
(<linetype>%1000)/100 or, if that is zero, the default line thickness.
`linewidth` is a synonym for `thickness`.

   Additional point-plot symbols are also available with the `fig`
driver. The symbols can be used through `pointtype` values % 100 above
50, with different fill intensities controlled by <pointtype> % 5 and
outlines in black (for <pointtype> % 10 < 5) or in the current color.
Available symbols are
             50 - 59:  circles
             60 - 69:  squares
             70 - 79:  diamonds
             80 - 89:  upwards triangles
             90 - 99:  downwards triangles

   The size of these symbols is linked to the font size.  The depth of
symbols is by default one less than the depth for lines to achieve nice
error bars.  If <pointtype> is above 1000, the depth is <layer> +
<pointtype>/1000-1.  If <pointtype>%1000 is above 100, the fill color
is (<pointtype>%1000)/100-1.

   Available fill colors are (from 1 to 9): black, blue, green, cyan,
red, magenta, yellow, white and dark blue (in monochrome mode: black
for 1 to 6 and white for 7 to 9).

   See *note with:: for details of <linetype> and <pointtype>.

   The `big` option is a substitute for the `bfig` terminal in earlier
versions, which is no longer supported.

   Examples:
           set terminal fig monochrome small pointsmax 1000  # defaults

           plot 'file.dat' with points linetype 102 pointtype 759

   would produce circles with a blue outline of width 1 and yellow fill
color.

           plot 'file.dat' using 1:2:3 with err linetype 1 pointtype 554

   would produce errorbars with black lines and circles filled red.
These circles are one layer above the lines (at depth 9 by default).

   To plot the error bars on top of the circles use
           plot 'file.dat' using 1:2:3 with err linetype 1 pointtype 2554"


File: gnuplot.info,  Node: png_,  Next: ggi,  Prev: fig,  Up: complete_list_of_terminals

4.1.0.22 png
............

Syntax:
           set terminal png
                  {{no}enhanced}
                  {{no}transparent} {{no}interlace}
                  {{no}truecolor} {rounded|butt}
                  {linewidth <lw>} {dashlength <dl>}
                  {tiny | small | medium | large | giant}
                  {font "<face> {,<pointsize>}"} {fontscale <scale>}
                  {size <x>,<y>} {{no}crop}
                  {background <rgb_color>}

   PNG, JPEG and GIF images are created using the external library
libgd.  PNG plots may be viewed interactively by piping the output to
the 'display' program from the ImageMagick package as follows:
                    set term png
                    set output '| display png:-'

   You can view the output from successive plot commands interactively
by typing <space> in the display window.  To save the current plot to a
file, left click in the display window and choose *note save::.

   `transparent` instructs the driver to make the background color
transparent.  Default is `notransparent`.

   `interlace` instructs the driver to generate interlaced PNGs.
Default is `nointerlace`.

   The `linewidth` and `dashlength` options are scaling factors that
affect all lines drawn, i.e. they are multiplied by values requested in
various drawing commands.

   By default output png images use 256 indexed colors. The `truecolor`
option instead creates TrueColor images with 24 bits of color
information per pixel.  Transparent fill styles require the `truecolor`
option. See `fillstyle`.  A transparent background is possible in
either indexed or TrueColor images.

   `butt` instructs the driver to use a line drawing method that does
not overshoot the desired end point of a line.  This setting is only
applicable for line widths greater than 1.  This setting is most useful
when drawing horizontal or vertical lines.  Default is `rounded`.

   The details of font selection are complicated.  Two equivalent
simple examples are given below:
          set term png font arial 11
          set term png font "arial,11"

   For more information please see the separate section under `fonts`.

   The output plot size <x,y> is given in pixels--it defaults to
640x480.  Please see additional information under `canvas` and *note
size::.  Blank space at the edges of the finished plot may be trimmed
using the `crop` option, resulting in a smaller final image size.
Default is `nocrop`.

-- EXAMPLES --

           set terminal png medium size 640,480 background '#ffffff'

   Use the medium size built-in non-scaleable, non-rotatable font.  Use
white (24-bit RGB in hexadecimal) for the non-transparent background.

           set terminal png font arial 14 size 800,600

   Searches for a scalable font with face name 'arial' and sets the font
size to 14pt.  Please see `fonts` for details of how the font search is
done.

           set terminal png transparent truecolor enhanced

   Use 24 bits of color information per pixel, with a transparent
background.  Use the `enhanced text` mode to control the layout of
strings to be printed.


File: gnuplot.info,  Node: ggi,  Next: gpic,  Prev: png_,  Up: complete_list_of_terminals

4.1.0.23 ggi
............

The `ggi` driver can run on different targets as X or svgalib.

   Syntax:
        set terminal ggi [acceleration <integer>] [[mode] {mode}]

   In X the window cannot be resized using window manager handles, but
the mode can be given with the mode option, e.g.:
      - V1024x768
      - V800x600
      - V640x480
      - V320x200

   Please refer to the ggi documentation for other modes. The 'mode'
keyword is optional. It is recommended to select the target by
environment variables as explained in the libggi manual page. To get
DGA on X, you should for example
        bash> export GGI_DISPLAY=DGA
        csh>  setenv GGI_DISPLAY DGA

   'acceleration' is only used for targets which report relative pointer
motion events (e.g. DGA) and is a strictly positive integer
multiplication factor for the relative distances.  The default for
acceleration is 7.

   Examples:
        set term ggi acc 10
        set term ggi acc 1 mode V1024x768
        set term ggi V1024x768"


File: gnuplot.info,  Node: gpic,  Next: grass,  Prev: ggi,  Up: complete_list_of_terminals

4.1.0.24 gpic
.............

The `gpic` terminal driver generates GPIC graphs in the Free Software
Foundations's "groff" package.  The default size is 5 x 3 inches.  The
only option is the origin, which defaults to (0,0).

   Syntax:
           set terminal gpic {<x> <y>}

   where `x` and `y` are in inches.

   A simple graph can be formatted using

           groff -p -mpic -Tps file.pic > file.ps.

   The output from pic can be pipe-lined into eqn, so it is possible to
put complex functions in a graph with the `set label` and `set
{x/y}label` commands.  For instance,

           set ylab '@space 0 int from 0 to x alpha ( t ) roman d t@'

   will label the y axis with a nice integral if formatted with the
command:

           gpic filename.pic | geqn -d@@ -Tps | groff -m[macro-package] -Tps
               > filename.ps

   Figures made this way can be scaled to fit into a document.  The pic
language is easy to understand, so the graphs can be edited by hand if
need be.  All co-ordinates in the pic-file produced by `gnuplot` are
given as x+gnuplotx and y+gnuploty.  By default x and y are given the
value 0.  If this line is removed with an editor in a number of files,
one can put several graphs in one figure like this (default size is
5.0x3.0 inches):

           .PS 8.0
           x=0;y=3
           copy "figa.pic"
           x=5;y=3
           copy "figb.pic"
           x=0;y=0
           copy "figc.pic"
           x=5;y=0
           copy "figd.pic"
           .PE

   This will produce an 8-inch-wide figure with four graphs in two rows
on top of each other.

   One can also achieve the same thing by the command

           set terminal gpic x y

   for example, using

           .PS 6.0
           copy "trig.pic"
           .PE"


File: gnuplot.info,  Node: grass,  Next: hp2623a,  Prev: gpic,  Up: complete_list_of_terminals

4.1.0.25 grass
..............

The `grass` terminal driver gives `gnuplot` capabilities to users of the
GRASS geographic information system.  Contact
grassp-list@moon.cecer.army.mil for more information.  Pages are
written to the current frame of the GRASS Graphics Window.  There are
no options."


File: gnuplot.info,  Node: hp2623a,  Next: hp2648,  Prev: grass,  Up: complete_list_of_terminals

4.1.0.26 hp2623a
................

The `hp2623a` terminal driver supports the Hewlett Packard HP2623A.  It
has no options."


File: gnuplot.info,  Node: hp2648,  Next: hp500c,  Prev: hp2623a,  Up: complete_list_of_terminals

4.1.0.27 hp2648
...............

The `hp2648` terminal driver supports the Hewlett Packard HP2647 and
HP2648.  It has no options."


File: gnuplot.info,  Node: hp500c,  Next: hpgl,  Prev: hp2648,  Up: complete_list_of_terminals

4.1.0.28 hp500c
...............

The `hp500c` terminal driver supports the Hewlett Packard HP DeskJet
500c.  It has options for resolution and compression.

   Syntax:
           set terminal hp500c {<res>} {<comp>}

   where `res` can be 75, 100, 150 or 300 dots per inch and `comp` can
be "rle", or "tiff".  Any other inputs are replaced by the defaults,
which are 75 dpi and no compression.  Rasterization at the higher
resolutions may require a large amount of memory."


File: gnuplot.info,  Node: hpgl,  Next: hpljii,  Prev: hp500c,  Up: complete_list_of_terminals

4.1.0.29 hpgl
.............

The `hpgl` driver produces HPGL output for devices like the HP7475A
plotter.  There are two options which can be set: the number of pens
and `eject`, which tells the plotter to eject a page when done.  The
default is to use 6 pens and not to eject the page when done.

   The international character sets ISO-8859-1 and CP850 are recognized
via `set encoding iso_8859_1` or `set encoding cp850` (see *note
encoding:: for details).

   Syntax:
           set terminal hpgl {<number_of_pens>} {eject}

   The selection

           set terminal hpgl 8 eject

   is equivalent to the previous `hp7550` terminal, and the selection

           set terminal hpgl 4

   is equivalent to the previous `hp7580b` terminal.

   The `pcl5` driver supports plotters such as the Hewlett-Packard
Designjet 750C, the Hewlett-Packard Laserjet III, and the
Hewlett-Packard Laserjet IV.  It actually uses HPGL-2, but there is a
name conflict among the terminal devices.  It has several options which
must be specified in the order indicated below:

   Syntax:
           set terminal pcl5 {mode <mode>} {<plotsize>}
               {{color {<number_of_pens>}} | monochrome} {solid | dashed}
               {font <font>} {size <fontsize>} {pspoints | nopspoints}

   <mode> is `landscape` or `portrait`. <plotsize> is the physical
plotting size of the plot, which is one of the following: `letter` for
standard (8 1/2" X 11") displays, `legal` for (8 1/2" X 14") displays,
`noextended` for (36" X 48") displays (a letter size ratio) or,
`extended` for (36" X 55") displays (almost a legal size ratio).
`color` is for multi-pen (i.e. color) plots, and <number_of_pens> is
the number of pens (i.e. colors) used in color plots. `monochrome` is
for one (e.g. black) pen plots. `solid` draws all lines as solid lines,
or `dashed` will draw lines with different dashed and dotted line
patterns.  <font> is `stick`, `univers`, `cg_times`, `zapf_dingbats`,
`antique_olive`, `arial`, `courier`, `garamond_antigua`,
`letter_gothic`, `cg_omega`, `albertus`, `times_new_roman`,
`clarendon`, `coronet`, `marigold`, `truetype_symbols`, or `wingdings`.
<fontsize> is the font size in points.  The point type selection can be
the standard default set by specifying `nopspoints`, or the same set of
point types found in the postscript terminal by specifying `pspoints`.

   Note that built-in support of some of these options is printer device
dependent. For instance, all the fonts are supposedly supported by the
HP Laserjet IV, but only a few (e.g. univers, stick) may be supported
by the HP Laserjet III and the Designjet 750C. Also, color obviously
won't work on the the laserjets since they are monochrome devices.

   Defaults: landscape, noextended, color (6 pens), solid, univers, 12
point,
               and nopspoints.

   With `pcl5` international characters are handled by the printer; you
just put the appropriate 8-bit character codes into the text strings.
You don't need to bother with *note encoding::.

   HPGL graphics can be imported by many software packages."


File: gnuplot.info,  Node: hpljii,  Next: hppj,  Prev: hpgl,  Up: complete_list_of_terminals

4.1.0.30 hpljii
...............

The `hpljii` terminal driver supports the HP Laserjet Series II
printer.  The `hpdj` driver supports the HP DeskJet 500 printer.  These
drivers allow a choice of resolutions.

   Syntax:
           set terminal hpljii | hpdj {<res>}

   where `res` may be 75, 100, 150 or 300 dots per inch; the default is
75.  Rasterization at the higher resolutions may require a large amount
of memory.

   The `hp500c` terminal is similar to `hpdj`; `hp500c` additionally
supports color and compression."


File: gnuplot.info,  Node: hppj,  Next: imagen,  Prev: hpljii,  Up: complete_list_of_terminals

4.1.0.31 hppj
.............

The `hppj` terminal driver supports the HP PaintJet and HP3630
printers.  The only option is the choice of font.

   Syntax:
           set terminal hppj {FNT5X9 | FNT9X17 | FNT13X25}

   with the middle-sized font (FNT9X17) being the default."


File: gnuplot.info,  Node: imagen,  Next: kyo,  Prev: hppj,  Up: complete_list_of_terminals

4.1.0.32 imagen
...............

The `imagen` terminal driver supports Imagen laser printers.  It is
capable of placing multiple graphs on a single page.

   Syntax:
           set terminal imagen {<fontsize>} {portrait | landscape}
                               {[<horiz>,<vert>]}

   where `fontsize` defaults to 12 points and the layout defaults to
`landscape`.  `<horiz>` and `<vert>` are the number of graphs in the
horizontal and vertical directions; these default to unity.

   Example:
           set terminal imagen portrait [2,3]

   puts six graphs on the page in three rows of two in portrait
orientation."


File: gnuplot.info,  Node: kyo,  Next: latex,  Prev: imagen,  Up: complete_list_of_terminals

4.1.0.33 kyo
............

The `kyo` and `prescribe` terminal drivers support the Kyocera laser
printer.  The only difference between the two is that `kyo` uses
"Helvetica" whereas `prescribe` uses "Courier".  There are no options."


File: gnuplot.info,  Node: latex,  Next: linux,  Prev: kyo,  Up: complete_list_of_terminals

4.1.0.34 latex
..............

Syntax:
           set terminal {latex | emtex} {default | {courier|roman} {<fontsize>}}
                        {size <XX>{unit}, <YY>{unit}} {rotate | norotate}

   By default the plot will inherit font settings from the embedding
document.  You have the option of forcing either Courier (cmtt) or
Roman (cmr) fonts instead. In this case you may also specify a fontsize.
Unless your driver is capable of building fonts at any size (e.g.
dvips), stick to the standard 10, 11 and 12 point sizes.

   METAFONT users beware: METAFONT does not like odd sizes.

   All drivers for LaTeX offer a special way of controlling text
positioning: If any text string begins with '{', you also need to
include a '}' at the end of the text, and the whole text will be
centered both horizontally and vertically.  If the text string begins
with '[', you need to follow this with a position specification (up to
two out of t,b,l,r), ']{', the text itself, and finally '}'.  The text
itself may be anything LaTeX can typeset as an LR-box.  '\\rule{}{}'s
may help for best positioning.

   Points, among other things, are drawn using the LaTeX commands
"\\Diamond" and "\\Box".  These commands no longer belong to the
LaTeX2e core; they are included in the latexsym package, which is part
of the base distribution and thus part of any LaTeX implementation.
Please do not forget to use this package.  Other point types use
symbols from the amssymb package.

   The default size for the plot is 5 inches by 3 inches. The *note
size:: option changes this to whatever the user requests. By default
the X and Y sizes are taken to be in inches, but other units are
possible (currently only cm).

   If 'rotate' is specified, rotated text, especially a rotated y-axis
label, is possible (the packages graphics or graphicx are needed). The
'stacked' y-axis label mechanism is then deactivated.

   Examples: About label positioning: Use gnuplot defaults (mostly
sensible, but sometimes not really best):
            set title '\\LaTeX\\ -- $ \\gamma $'

   Force centering both horizontally and vertically:
            set label '{\\LaTeX\\ -- $ \\gamma $}' at 0,0

   Specify own positioning (top here):
            set xlabel '[t]{\\LaTeX\\ -- $ \\gamma $}'

   The other label - account for long ticlabels:
            set ylabel '[r]{\\LaTeX\\ -- $ \\gamma $\\rule{7mm}{0pt}}'"


File: gnuplot.info,  Node: linux,  Next: lua,  Prev: latex,  Up: complete_list_of_terminals

4.1.0.35 linux
..............

The `linux` driver has no additional options to specify.  It looks at
the environment variable GSVGAMODE for the default mode; if not set, it
uses 1024x768x256 as default mode or, if that is not possible,
640x480x16 (standard VGA)."


File: gnuplot.info,  Node: lua,  Next: macintosh,  Prev: linux,  Up: complete_list_of_terminals

4.1.0.36 lua
............

The `lua` generic terminal driver works in conjunction with an external
Lua script to create a target-specific plot file.  Currently the only
supported target is TikZ -> pdflatex.

   Information about Lua is available at http://www.lua.org .

   Syntax:
        set terminal lua <target name> | "<file name>"
                            {<script_args> ...}
                            {help}

   A 'target name' or 'file name' (in quotes) for a script is mandatory.
If a 'target name' for the script is given, the terminal will look for
"gnuplot-<target name>.lua" in the local directory and on failure in
the environmental variable GNUPLOT_LUA_DIR.

   All arguments will be provided to the selected script for further
evaluation. E.g. 'set term lua tikz help' will cause the script itself
to print additional help on options and choices for the script.


File: gnuplot.info,  Node: macintosh,  Next: mf,  Prev: lua,  Up: complete_list_of_terminals

4.1.0.37 macintosh
..................

Syntax:
          set terminal macintosh {singlewin | multiwin} {vertical | novertical}
                                 {size <width>, <height> | default}

   'singlewin' limits the output to a single window and is useful for
animations.  'multiwin' allows multiple windows.  'vertical' is only
valid under the gx option. With this option, rotated text will be drawn
vertically. novertical turns this option off.  size <width>, <height>
overrides the graph size set in the preferences dialog until it is
cleared with either 'set term mac size default' or 'set term mac
default'.

   'set term mac size default' sets the window size settings to those
set in the preferences dialog.

   'set term mac default' sets all options to their default values.
Default values: nogx, multiwin, novertical.

   If you generate graphs under the multiwin option and then switch to
singlewin, the next plot command will cause one more window to be
created. This new window will be reused as long as singlewin is in
effect. If you switch back to multiwin, generate some graphs, and then
switch to singlewin again, the orginal 'singlewin' window will be
resused if it is still open. Otherwise a new 'singlewin' window will be
created. The 'singlewin' window is not numbered."


File: gnuplot.info,  Node: mf,  Next: mp,  Prev: macintosh,  Up: complete_list_of_terminals

4.1.0.38 mf
...........

The `mf` terminal driver creates an input file to the METAFONT program.
Thus a figure may be used in the TeX document in the same way as is a
character.

   To use a picture in a document, the METAFONT program must be run
with the output file from `gnuplot` as input.  Thus, the user needs a
basic knowledge of the font creating process and the procedure for
including a new font in a document.  However, if the METAFONT program
is set up properly at the local site, an unexperienced user could
perform the operation without much trouble.

   The text support is based on a METAFONT character set.  Currently the
Computer Modern Roman font set is input, but the user is in principal
free to choose whatever fonts he or she needs.  The METAFONT source
files for the chosen font must be available.  Each character is stored
in a separate picture variable in METAFONT.  These variables may be
manipulated (rotated, scaled etc.) when characters are needed.  The
drawback is the interpretation time in the METAFONT program.  On some
machines (i.e. PC) the limited amount of memory available may also
cause problems if too many pictures are stored.

   The `mf` terminal has no options.

-- METAFONT INSTRUCTIONS --

   - Set your terminal to METAFONT:
       set terminal mf

   - Select an output-file, e.g.:
       set output "myfigures.mf"

   - Create your pictures. Each picture will generate a separate
character. Its default size will be 5*3 inches. You can change the size
by saying `set size 0.5,0.5` or whatever fraction of the default size
you want to have.

   - Quit `gnuplot`.

   - Generate a TFM and GF file by running METAFONT on the output of
`gnuplot`.  Since the picture is quite large (5*3 in), you will have to
use a version of METAFONT that has a value of at least 150000 for
memmax.  On Unix systems these are conventionally installed under the
name bigmf.  For the following assume that the command virmf stands for
a big version of METAFONT.  For example:

   - Invoke METAFONT:
         virmf '&plain'

   - Select the output device: At the METAFONT prompt ('*') type:
         \\mode:=CanonCX;     % or whatever printer you use

   - Optionally select a magnification:
         mag:=1;             % or whatever you wish

   - Input the `gnuplot`-file:
         input myfigures.mf

   On a typical Unix machine there will usually be a script called "mf"
that executes virmf '&plain', so you probably can substitute mf for
virmf &plain.  This will generate two files: mfput.tfm and mfput.$$$gf
(where $$$ indicates the resolution of your device).  The above can be
conveniently achieved by typing everything on the command line, e.g.:
virmf '&plain' '\\mode:=CanonCX; mag:=1; input myfigures.mf' In this
case the output files will be named myfigures.tfm and myfigures.300gf.

   - Generate a PK file from the GF file using gftopk:
       gftopk myfigures.300gf myfigures.300pk

   The name of the output file for gftopk depends on the DVI driver you
use.  Ask your local TeX administrator about the naming conventions.
Next, either install the TFM and PK files in the appropriate
directories, or set your environment variables properly.  Usually this
involves setting TEXFONTS to include the current directory and doing
the same thing for the environment variable that your DVI driver uses
(no standard name here...).  This step is necessary so that TeX will
find the font metric file and your DVI driver will find the PK file.

   - To include your pictures in your document you have to tell TeX the
font:
       \\font\\gnufigs=myfigures

   Each picture you made is stored in a single character.  The first
picture is character 0, the second is character 1, and so on...  After
doing the above step, you can use the pictures just like any other
characters.  Therefore, to place pictures 1 and 2 centered in your
document, all you have to do is:
       \\centerline{\\gnufigs\\char0}
       \\centerline{\\gnufigs\\char1}

   in plain TeX.  For LaTeX you can, of course, use the picture
environment and place the picture wherever you wish by using the
\\makebox and \\put macros.

   This conversion saves you a lot of time once you have generated the
font; TeX handles the pictures as characters and uses minimal time to
place them, and the documents you make change more often than the
pictures do.  It also saves a lot of TeX memory.  One last advantage of
using the METAFONT driver is that the DVI file really remains device
independent, because no \\special commands are used as in the eepic and
tpic drivers."


File: gnuplot.info,  Node: mp,  Next: mif,  Prev: mf,  Up: complete_list_of_terminals

4.1.0.39 mp
...........

The `mp` driver produces output intended to be input to the Metapost
program.  Running Metapost on the file creates EPS files containing the
plots. By default, Metapost passes all text through TeX.  This has the
advantage of allowing essentially  any TeX symbols in titles and labels.

   Syntax:
        set term mp {color | colour | monochrome}
                    {solid | dashed}
                    {notex | tex | latex}
                    {magnification <magsize>}
                    {psnfss | psnfss-version7 | nopsnfss}
                    {prologues <value>}
                    {a4paper}
                    {amstex}
                    {"<fontname> {,<fontsize>}"}

   The option `color` causes lines to be drawn in color (on a printer
or display that supports it), `monochrome` (or nothing) selects black
lines.  The option `solid` draws solid lines, while `dashed` (or
nothing) selects lines with different patterns of dashes.  If `solid`
is selected but `color` is not, nearly all lines will be identical.
This may occasionally be useful, so it is allowed.

   The option `notex` bypasses TeX entirely, therefore no TeX code can
be used in labels under this option.  This is intended for use on old
plot files or files that make frequent use of common characters like
`$` and `%` that require special handling in TeX.

   The option `tex` sets the terminal to output its text for TeX to
process.

   The option `latex` sets the terminal to output its text for
processing by LaTeX. This allows things like \\frac for fractions which
LaTeX knows about but TeX does not.  Note that you must set the
environment variable TEX to the name of your LaTeX executable (normally
latex) if you use this option or use `mpost -tex=<name of LaTeX
executable> ...`. Otherwise metapost will try and use TeX to process
the text and it won't work.

   Changing font sizes in TeX has no effect on the size of mathematics,
and there is no foolproof way to make such a change, except by globally
setting a magnification factor. This is the purpose of the
`magnification` option. It must be followed by a scaling factor. All
text (NOT the graphs) will be scaled by this factor. Use this if you
have math that you want at some size other than the default 10pt.
Unfortunately, all math will be the same size, but see the discussion
below on editing the MP output. `mag` will also work under `notex` but
there seems no point in using it as the font size option (below) works
as well.

   The option `psnfss` uses postscript fonts in combination with LaTeX.
Since this option only makes sense, if LaTeX is being used, the `latex`
option is selected automatically. This option includes the following
packages for LaTeX: inputenc(latin1), fontenc(T1), mathptmx,
helvet(scaled=09.2), courier, latexsym and textcomp.

   The option `psnfss-version7` uses also postscript fonts in LaTeX
(option `latex` is also automatically selected), but uses the following
packages with LaTeX: inputenc(latin1), fontenc(T1), times, mathptmx,
helvet and courier.

   The option `nopsnfss` is the default and uses the standard font
(cmr10 if not otherwise specified).

   The option `prologues` takes a value as an additional argument and
adds the line `prologues:=<value>` to the metapost file. If a value of
`2` is specified metapost uses postscript fonts to generate the
eps-file, so that the result can be viewed using e.g. ghostscript.
Normally the output of metapost uses TeX fonts and therefore has to be
included in a (La)TeX file before you can look at it.

   The option `noprologues` is the default. No additional line
specifying the prologue will be added.

   The option `a4paper` adds a `[a4paper]` to the documentclass.
Normally letter paper is used (default). Since this option is only used
in case of LaTeX, the `latex` option is selected automatically.

   The option `amstex` automatically selects the `latex` option and
includes the following LaTeX packages: amsfonts, amsmath(intlimits). By
default these packages are not included.

   A name in quotes selects the font that will be used when no explicit
font is given in a `set label` or *note title::.  A name recognized by
TeX (a TFM file exists) must be used.  The default is "cmr10" unless
`notex` is selected, then it is "pcrr8r" (Courier).  Even under
`notex`, a TFM file is needed by Metapost. The file `pcrr8r.tfm` is the
name given to Courier in LaTeX's psnfss package.  If you change the
font from the `notex` default, choose a font that matches the ASCII
encoding at least in the range 32-126.  `cmtt10` almost works, but it
has a nonblank character in position 32 (space).

   The size can be any number between 5.0 and 99.99.  If it is omitted,
10.0 is used.  It is advisable to use `magstep` sizes: 10 times an
integer or half-integer power of 1.2, rounded to two decimals, because
those are the most available sizes of fonts in TeX systems.

   All the options are optional.  If font information is given, it must
be at the end, with size (if present) last.  The size is needed to
select a size for the font, even if the font name includes size
information.  For example, `set term mp "cmtt12"` selects cmtt12 shrunk
to the default size 10.  This is probably not what you want or you
would have used cmtt10.

   The following common ascii characters need special treatment in TeX:
        $, &, #, %, _;  |, <, >;  ^, ~,  \\, {, and }

   The five characters $, #, &, _, and % can simply be escaped, e.g.,
`\\$`.  The three characters <, >, and | can be wrapped in math mode,
e.g., `$<$`.  The remainder require some TeX work-arounds.  Any good
book on TeX will give some guidance.

   If you type your labels inside double quotes, backslashes in TeX
code need to be escaped (doubled). Using single quotes will avoid
having to do this, but then you cannot use `\\n` for line breaks.  As
of this writing, version 3.7 of gnuplot processes titles given in a
`plot` command differently than in other places, and backslashes in TeX
commands need to be doubled regardless of the style of quotes.

   Metapost pictures are typically used in TeX documents.  Metapost
deals with fonts pretty much the same way TeX does, which is different
from most other document preparation programs.  If the picture is
included in a LaTeX document using the graphics package, or in a
plainTeX document via epsf.tex, and then converted to PostScript with
dvips (or other dvi-to-ps converter), the text in the plot will usually
be handled correctly.  However, the text may not appear if you send the
Metapost output as-is to a PostScript interpreter.

-- METAPOST INSTRUCTIONS --

   - Set your terminal to Metapost, e.g.:
        set terminal mp mono "cmtt12" 12

   - Select an output-file, e.g.:
        set output "figure.mp"

   - Create your pictures.  Each plot (or multiplot group) will
generate a separate Metapost beginfig...endfig group.  Its default size
will be 5 by 3 inches.  You can change the size by saying `set size
0.5,0.5` or whatever fraction of the default size you want to have.

   - Quit gnuplot.

   - Generate EPS files by running Metapost on the output of gnuplot:
        mpost figure.mp  OR  mp figure.mp

   The name of the Metapost program depends on the system, typically
`mpost` for a Unix machine and `mp` on many others.  Metapost will
generate one EPS file for each picture.

   - To include your pictures in your document you can use the graphics
package in LaTeX or epsf.tex in plainTeX:
        \\usepackage{graphics} % LaTeX
        \\input epsf.tex       % plainTeX

   If you use a driver other than dvips for converting TeX DVI output
to PS, you may need to add the following line in your LaTeX document:
        \\DeclareGraphicsRule{*}{eps}{*}{}

   Each picture you made is in a separate file.  The first picture is
in, e.g., figure.0, the second in figure.1, and so on....  To place the
third picture in your document, for example, all you have to do is:
        \\includegraphics{figure.2} % LaTeX
        \\epsfbox{figure.2}         % plainTeX

   The advantage, if any, of the mp terminal over a postscript terminal
is editable output.  Considerable effort went into making this output
as clean as possible.  For those knowledgeable in the Metapost
language, the default line types and colors can be changed by editing
the arrays `lt[]` and `col[]`.  The choice of solid vs dashed lines,
and color vs black lines can be change by changing the values assigned
to the booleans `dashedlines` and `colorlines`.  If the default `tex`
option was in effect, global changes to the text of labels can be
achieved by editing the `vebatimtex...etex` block.  In particular, a
LaTeX preamble can be added if desired, and then LaTeX's built-in size
changing commands can be used for maximum flexibility. Be sure to set
the appropriate MP configuration variable to force Metapost to run
LaTeX instead of plainTeX."


File: gnuplot.info,  Node: mif,  Next: next,  Prev: mp,  Up: complete_list_of_terminals

4.1.0.40 mif
............

The `mif` terminal driver produces Frame Maker MIF format version 3.00.
It plots in MIF Frames with the size 15*10 cm, and plot primitives with
the same pen will be grouped in the same MIF group.  Plot primitives in
a `gnuplot` page will be plotted in a MIF Frame, and several MIF Frames
are collected in one large MIF Frame.  The MIF font used for text is
"Times".

   Several options may be set in the MIF 3.00 driver.

   Syntax:
           set terminal mif {color | colour | monochrome} {polyline | vectors}
                            {help | ?}

   `colour` plots lines with line types >= 0 in colour (MIF sep. 2-7)
and `monochrome` plots all line types in black (MIF sep. 0).
`polyline` plots curves as continuous curves and *note vectors:: plots
curves as collections of vectors.  *note help:: and `?` print online
help on standard error output--both print a short description of the
usage; *note help:: also lists the options.

   Examples:
           set term mif colour polylines    # defaults
           set term mif                     # defaults
           set term mif vectors
           set term mif help"


File: gnuplot.info,  Node: next,  Next: Openstep_(next),  Prev: mif,  Up: complete_list_of_terminals

4.1.0.41 next
.............

Several options may be set in the next driver.

   Syntax:
           set terminal next {<mode>} {<type> } {<color>} {<dashed>}
                      {"<fontname>"} {<fontsize>} title {"<newtitle>"}

   where <mode> is  `default`, which sets all options to their defaults;
<type> is either `new` or `old`, where `old` invokes the old single
window; <color> is either `color` or `monochrome`; <dashed> is either
`solid` or `dashed`; "<fontname>" is the name of a valid PostScript
font; <fontsize> is the size of the font in PostScript points; and
<title> is the title for the GnuTerm window.  Defaults are  `new`,
`monochrome`, `dashed`, "Helvetica", 14pt.

   Examples:
           set term next default
           set term next 22
           set term next color "Times-Roman" 14
           set term next color "Helvetica" 12 title "MyPlot"
           set term next old

   Pointsizes may be changed with `set linestyle`."


File: gnuplot.info,  Node: Openstep_(next),  Next: pbm,  Prev: next,  Up: complete_list_of_terminals

4.1.0.42 Openstep (next)
........................

/* 

   */ Several options may be set in the openstep (next) driver.

   Syntax:
           set terminal openstep {<mode>} {<type> } {<color>} {<dashed>}
                      {"<fontname>"} {<fontsize>} title {"<newtitle>"}

   where <mode> is  `default`, which sets all options to their defaults;
<type> is either `new` or `old`, where `old` invokes the old single
window; <color> is either `color` or `monochrome`; <dashed> is either
`solid` or `dashed`; "<fontname>" is the name of a valid PostScript
font; <fontsize> is the size of the font in PostScript points; and
<title> is the title for the GnuTerm window.  Defaults are  `new`,
`monochrome`, `dashed`, "Helvetica", 14pt.

   Examples:
           set term openstep default
           set term openstep 22
           set term openstep color "Times-Roman" 14
           set term openstep color "Helvetica" 12 title "MyPlot"
           set term openstep old

   Pointsizes may be changed with `set linestyle`."


File: gnuplot.info,  Node: pbm,  Next: dospc,  Prev: Openstep_(next),  Up: complete_list_of_terminals

4.1.0.43 pbm
............

Syntax:
           set terminal pbm {<fontsize>} {<mode>} {size <x>,<y>}

   where <fontsize> is `small`, `medium`, or `large` and <mode> is
`monochrome`, `gray` or `color`.  The default plot size is 640 pixels
wide and 480 pixels high. The output size is white-space padded to the
nearest multiple of 8 pixels on both x and y. This empty space may be
cropped later if needed.

   The output of the `pbm` driver depends upon <mode>: `monochrome`
produces a portable bitmap (one bit per pixel), `gray` a portable
graymap (three bits per pixel) and `color` a portable pixmap (color,
four bits per pixel).

   The output of this driver can be used with various image conversion
and manipulation utilities provided by NETPBM.  Based on Jef Poskanzer's
PBMPLUS package, NETPBM provides programs to convert the above PBM
formats to GIF, TIFF, MacPaint, Macintosh PICT, PCX, X11 bitmap and
many others.  Complete information is available at
http://netpbm.sourceforge.net/.

   Examples:
           set terminal pbm small monochrome                # defaults
           set terminal pbm color medium size 800,600
           set output '| pnmrotate 45 | pnmtopng > tilted.png'  # uses NETPBM"


File: gnuplot.info,  Node: dospc,  Next: pdf,  Prev: pbm,  Up: complete_list_of_terminals

4.1.0.44 dospc
..............

The `dospc` terminal driver supports PCs with arbitrary graphics boards,
which will be automatically detected.  It should be used only if you are
not using the gcc or Zortec C/C++ compilers."


File: gnuplot.info,  Node: pdf,  Next: pstricks,  Prev: dospc,  Up: complete_list_of_terminals

4.1.0.45 pdf
............

This terminal produces files in the Adobe Portable Document Format
(PDF), useable for printing or display with tools like Acrobat Reader

   Syntax:
           set terminal pdf {monochrome|color|colour}
                            {{no}enhanced}
                            {fname "<font>"} {fsize <fontsize>}
                            {font "<fontname>{,<fontsize>}"} {fontscale <scale>}
                            {linewidth <lw>} {rounded|butt}
                            {solid|dashed} {dl <dashlength>}}
                            {size <XX>{unit},<YY>{unit}}

   The default is to use a different color for each line type. Selecting
`monochome` will use black for all linetypes, in which case you probably
want to select `dashed` to distinguish line types. Even in in mono mode
you can still use explicit colors for filled areas or linestyles.

   where <font> is the name of the default font to use (default
Helvetica) and <fontsize> is the font size (in points, default 12).
For help on which fonts are available or how to install new ones, please
see the documentation for your local installation of pdflib.

   The `enhanced` option enables enhanced text processing features
(subscripts, superscripts and mixed fonts). See `enhanced`.

   The width of all lines in the plot can be increased by the factor <n>
specified in `linewidth`. Similarly `dashlength` is a multiplier for the
default dash spacing.

   `rounded` sets line caps and line joins to be rounded; `butt` is the
default, butt caps and mitered joins.

   The default size for PDF output is 5 inches by 3 inches. The *note
size:: option changes this to whatever the user requests. By default
the X and Y sizes are taken to be in inches, but other units are
possible (currently only cm).

   * does not work.


File: gnuplot.info,  Node: pstricks,  Next: qms,  Prev: pdf,  Up: complete_list_of_terminals

4.1.0.46 pstricks
.................

The `pstricks` driver is intended for use with the "pstricks.sty" macro
package for LaTeX.  It is an alternative to the `eepic` and `latex`
drivers.  You need "pstricks.sty", and, of course, a printer that
understands PostScript, or a converter such as Ghostscript.

   PSTricks is available via anonymous ftp from the /pub directory at
Princeton.edu.  This driver definitely does not come close to using the
full capability of the PSTricks package.

   Syntax:
           set terminal pstricks {hacktext | nohacktext} {unit | nounit}

   The first option invokes an ugly hack that gives nicer numbers; the
second has to do with plot scaling.  The defaults are `hacktext` and
`nounit`."


File: gnuplot.info,  Node: qms,  Next: regis,  Prev: pstricks,  Up: complete_list_of_terminals

4.1.0.47 qms
............

The `qms` terminal driver supports the QMS/QUIC Laser printer, the
Talaris 1200 and others.  It has no options."


File: gnuplot.info,  Node: regis,  Next: sun,  Prev: qms,  Up: complete_list_of_terminals

4.1.0.48 regis
..............

The `regis` terminal device generates output in the REGIS graphics
language.  It has the option of using 4 (the default) or 16 colors.

   Syntax:
           set terminal regis {4 | 16}"


File: gnuplot.info,  Node: sun,  Next: svg,  Prev: regis,  Up: complete_list_of_terminals

4.1.0.49 sun
............

The `sun` terminal driver supports the SunView window system.  It has no
options."


File: gnuplot.info,  Node: svg,  Next: tek410x,  Prev: sun,  Up: complete_list_of_terminals

4.1.0.50 svg
............

This terminal produces files in the W3C Scalable Vector Graphics format.

   Syntax:
           set terminal svg {size <x>,<y> {|fixed|dynamic}}
                            {{no}enhanced}
                            {fname "<font>"} {fsize <fontsize>}
                            {mouse} {standalone | jsdir <dirname>}
                            {name <plotname>}
                            {font "<fontname>{,<fontsize>}"}
                            {fontfile <filename>}
                            {rounded|butt} {solid|dashed} {linewidth <lw>}
                            {background <rgb_color>}

   where <x> and <y> are the size of the SVG plot to generate,
`dynamic` allows a svg-viewer to resize plot, whereas the default
setting, `fixed`, will request an absolute size.

   `linewidth <w>` increases the width of all lines used in the figure
by a factor of <w>.

   <font> is the name of the default font to use (default Arial) and
<fontsize> is the font size (in points, default 12). SVG viewing
programs may substitute other fonts when the file is displayed.

   The svg terminal supports an enhanced text mode, which allows font
and other formatting commands to be embedded in labels and other text
strings. The enhanced text mode syntax is shared with other gnuplot
terminal types. See `enhanced` for more details.

   The `mouse` option tells gnuplot to add support for mouse tracking
and for toggling individual plots on/off by clicking on the
corresponding key entry.  By default this is done by including a link
that points to a script in a local directory, usually
/usr/local/share/gnuplot/<version>/js.  You can change this by using
the `jsdir` option to specify either a different local directory or a
general URL. The latter is usually appropriate if you are embedding the
svg into a web page.  Alternatively, the `standalone` option embeds the
mousing code in the svg document itself rather than linking to an
external resource.

   SVG allows you to embed fonts directly into an SVG document, or to
provide a hypertext link to the desired font. The `fontfile` option
specifies a local file which is copied into the <defs> section of the
resulting SVG output file.  This file may either itself contain a font,
or may contain the records necessary to create a hypertext reference to
the desired font. Gnuplot will look for the requested file using the
directory list in the GNUPLOT_FONTPATH environmental variable.  NB: You
must embed an svg font, not a TrueType or PostScript font."


File: gnuplot.info,  Node: tek410x,  Next: tek40,  Prev: svg,  Up: complete_list_of_terminals

4.1.0.51 tek410x
................

The `tek410x` terminal driver supports the 410x and 420x family of
Tektronix terminals.  It has no options."


File: gnuplot.info,  Node: tek40,  Next: texdraw,  Prev: tek410x,  Up: complete_list_of_terminals

4.1.0.52 tek40
..............

This family of terminal drivers supports a variety of VT-like terminals.
`tek40xx` supports Tektronix 4010 and others as well as most TEK
emulators.  `vttek` supports VT-like tek40xx terminal emulators.  The
following are present only if selected when gnuplot is built:
`kc-tek40xx` supports MS-DOS Kermit Tek4010 terminal emulators in color;
`km-tek40xx` supports them in monochrome. `selanar` supports Selanar
graphics.  `bitgraph` supports BBN Bitgraph terminals.  None have any
options."


File: gnuplot.info,  Node: texdraw,  Next: tgif,  Prev: tek40,  Up: complete_list_of_terminals

4.1.0.53 texdraw
................

The `texdraw` terminal driver supports the LaTeX texdraw environment.
It is intended for use with "texdraw.sty" and "texdraw.tex" in the
texdraw package.

   Points, among other things, are drawn using the LaTeX commands
"\\Diamond" and "\\Box".  These commands no longer belong to the
LaTeX2e core; they are included in the latexsym package, which is part
of the base distribution and thus part of any LaTeX implementation.
Please do not forget to use this package.

   It has no options."


File: gnuplot.info,  Node: tgif,  Next: tkcanvas,  Prev: texdraw,  Up: complete_list_of_terminals

4.1.0.54 tgif
.............

Tgif is an X11-based drawing tool--it has nothing to do with GIF.

   The `tgif` driver supports different pointsizes (with *note
pointsize::), different label fonts and font sizes (e.g. `set label
"Hallo" at x,y font "Helvetica,34"`) and multiple graphs on the page.
The proportions of the axes are not changed.

   Syntax:
           set terminal tgif {portrait | landscape | default} {<[x,y]>}
                             {monochrome | color}
                             {{linewidth | lw} <LW>}
                             {solid | dashed}
                             {font "<fontname>{,<fontsize>}"}

   where <[x,y]> specifies the number of graphs in the x and y
directions on the page, `color` enables color, `linewidth` scales all
linewidths by <LW>, "<fontname>" is the name of a valid PostScript
font, and <fontsize> specifies the size of the PostScript font.
`defaults` sets all options to their defaults: `portrait`, `[1,1]`,
`color`, `linwidth 1.0`, `dashed`, `"Helvetica,18"`.

   The `solid` option is usually prefered if lines are colored, as they
often are in the editor.  Hardcopy will be black-and-white, so `dashed`
should be chosen for that.

   Multiplot is implemented in two different ways.

   The first multiplot implementation is the standard gnuplot multiplot
feature:

           set terminal tgif
           set output "file.obj"
           set multiplot
           set origin x01,y01
           set size  xs,ys
           plot ...
                ...
           set origin x02,y02
           plot ...
           unset multiplot

   See *note multiplot:: for further information.

   The second version is the [x,y] option for the driver itself.  The
advantage of this implementation is that everything is scaled and
placed automatically without the need for setting origins and sizes;
the graphs keep their natural x/y proportions of 3/2 (or whatever is
fixed by *note size::).

   If both multiplot methods are selected, the standard method is
chosen and a warning message is given.

   Examples of single plots (or standard multiplot):
           set terminal tgif                  # defaults
           set terminal tgif "Times-Roman,24"
           set terminal tgif landscape
           set terminal tgif landscape solid

   Examples using the built-in multiplot mechanism:
           set terminal tgif portrait [2,4]  # portrait; 2 plots in the x-
                                             # and 4 in the y-direction
           set terminal tgif [1,2]           # portrait; 1 plot in the x-
                                             # and 2 in the y-direction
           set terminal tgif landscape [3,3] # landscape; 3 plots in both
                                             # directions"


File: gnuplot.info,  Node: tkcanvas,  Next: tpic,  Prev: tgif,  Up: complete_list_of_terminals

4.1.0.55 tkcanvas
.................

This terminal driver generates Tk canvas widget commands based on Tcl/Tk
(default) or Perl.  To use it, rebuild `gnuplot` (after uncommenting or
inserting the appropriate line in "term.h"), then

      gnuplot> set term tkcanvas {perltk} {interactive}
      gnuplot> set output 'plot.file'

   After invoking "wish", execute the following sequence of Tcl/Tk
commands:

      % source plot.file
      % canvas .c
      % pack .c
      % gnuplot .c

   Or, for Perl/Tk use a program like this:

      use Tk;
      my $top = MainWindow->new;
      my $c = $top->Canvas->pack;
      my $gnuplot = do "plot.pl";
      $gnuplot->($c);
      MainLoop;

   The code generated by `gnuplot` creates a procedure called "gnuplot"
that takes the name of a canvas as its argument.  When the procedure is
called, it clears the canvas, finds the size of the canvas and draws
the plot in it, scaled to fit.

   For 2-dimensional plotting (`plot`) two additional procedures are
defined: "gnuplot_plotarea" will return a list containing the borders
of the plotting area "xleft, xright, ytop, ybot" in canvas screen
coordinates, while the ranges of the two axes "x1min, x1max, y1min,
y1max, x2min, x2max, y2min, y2max" in plot coordinates can be obtained
calling "gnuplot_axisranges".  If the "interactive" option is
specified, mouse clicking on a line segment will print the coordinates
of its midpoint to stdout. Advanced actions can happen instead if the
user supplies a procedure named "user_gnuplot_coordinates", which takes
the following arguments: "win id x1s y1s x2s y2s x1e y1e x2e y2e x1m
y1m x2m y2m", the name of the canvas and the id of the line segment
followed by the coordinates of its start and end point in the two
possible axis ranges; the coordinates of the midpoint are only filled
for logarithmic axes.

   The current version of `tkcanvas` supports neither *note multiplot::
nor *note replot::."


File: gnuplot.info,  Node: tpic,  Next: unixpc,  Prev: tkcanvas,  Up: complete_list_of_terminals

4.1.0.56 tpic
.............

The `tpic` terminal driver supports the LaTeX picture environment with
tpic \\specials.  It is an alternative to the `latex` and `eepic`
terminal drivers.  Options are the point size, line width, and dot-dash
interval.

   Syntax:
           set terminal tpic <pointsize> <linewidth> <interval>

   where *note pointsize:: and `linewidth` are integers in milli-inches
and `interval` is a float in inches.  If a non-positive value is
specified, the default is chosen: pointsize = 40, linewidth = 6,
interval = 0.1.

   All drivers for LaTeX offer a special way of controlling text
positioning: If any text string begins with '{', you also need to
include a '}' at the end of the text, and the whole text will be
centered both horizontally and vertically by LaTeX. -- If the text
string begins with '[', you need to continue it with: a position
specification (up to two out of t,b,l,r), ']{', the text itself, and
finally, '}'. The text itself may be anything LaTeX can typeset as an
LR-box. \\rule{}{}'s may help for best positioning.

   Examples: About label positioning: Use gnuplot defaults (mostly
sensible, but sometimes not really best):
            set title '\\LaTeX\\ -- $ \\gamma $'

   Force centering both horizontally and vertically:
            set label '{\\LaTeX\\ -- $ \\gamma $}' at 0,0

   Specify own positioning (top here):
            set xlabel '[t]{\\LaTeX\\ -- $ \\gamma $}'

   The other label - account for long ticlabels:
            set ylabel '[r]{\\LaTeX\\ -- $ \\gamma $\\rule{7mm}{0pt}}'"


File: gnuplot.info,  Node: unixpc,  Next: vx384,  Prev: tpic,  Up: complete_list_of_terminals

4.1.0.57 unixpc
...............

The `unixpc` terminal driver supports AT&T 3b1 and AT&T 7300 Unix PC.
It has no options."


File: gnuplot.info,  Node: vx384,  Next: vgagl,  Prev: unixpc,  Up: complete_list_of_terminals

4.1.0.58 vx384
..............

The `vx384` terminal driver supports the Vectrix 384 and Tandy color
printers.  It has no options."


File: gnuplot.info,  Node: vgagl,  Next: VWS,  Prev: vx384,  Up: complete_list_of_terminals

4.1.0.59 vgagl
..............

The `vgagl` driver is a fast linux console driver with full mouse and
pm3d support.  It looks at the environment variable
SVGALIB_DEFAULT_MODE for the default mode; if not set, it uses a 256
color mode with the highest available resolution.

   Syntax:
        set terminal vgagl \\
                     background [red] [[green] [blue]] \\
                     [uniform | interpolate] \\
                     [dump "file"] \\
                     [mode]

   The color mode can also be given with the mode option. Both Symbolic
names as G1024x768x256 and integers are allowed. The `background` option
takes either one or three integers in the range [0, 255]. If only one
integers is supplied, it is taken as gray value for the background.  If
three integers are present, the background gets the corresponding color.
The (mutually exclusive) options *note interpolate:: and `uniform`
control if color interpolation is done while drawing triangles (on by
default).

   A `screen dump file` can be specified with the `dump "file"` option.
If this option is present, (i.e the dump file name is not empty)
pressing the key KP_Delete will write the file.  This action cannot and
cannot be rebound. The file is written in raw ppm (P6) format. Note
that this option is reset each time the `set term` command is issued.

   To get high resolution modes, you will probably have to modify the
configuration file of libvga, usually /etc/vga/libvga.conf.  Using the
VESA fb is a good choice, but this needs to be compiled in the kernel.

   The vgagl driver uses the first *available* vga mode from the
following list:
      - the driver which was supplied when setting vgagl, e.g. `set term vgagl
        G1024x768x256` would first check, if the G1024x768x256 mode is available.
      - the environment variable SVGALIB_DEFAULT_MODE
      - G1024x768x256
      - G800x600x256
      - G640x480x256
      - G320x200x256
      - G1280x1024x256
      - G1152x864x256
      - G1360x768x256
      - G1600x1200x256


File: gnuplot.info,  Node: VWS,  Next: windows,  Prev: vgagl,  Up: complete_list_of_terminals

4.1.0.60 VWS
............

The `VWS` terminal driver supports the VAX Windowing System.  It has no
options.  It will sense the display type (monochrome, gray scale, or
color.)  All line styles are plotted as solid lines."


File: gnuplot.info,  Node: windows,  Next: wxt,  Prev: VWS,  Up: complete_list_of_terminals

4.1.0.61 windows
................

The `windows` terminal is a fast interactive terminal driver that uses
the Windows GDI to draw and write text. The cross-platform `terminal
wxt` is also supported on Windows.

   Syntax:
           set terminal windows {<n>}
                                {color | monochrome}
                                {solid | dashed}
                                {enhanced | noenhanced}
                                {font <fontspec>}
                                {fontscale <scale>}
                                {linewdith <scale>}
                                {background <rgb color>}
                                {title "Plot Window Title"}
                                {size <width>,<height>}
                                {position <x>,<y>}
                                {close}

   Multiple plot windows are supported: `set terminal win <n>` directs
the output to plot window number n.

   `color` and `monochrome` select colored or mono output, `dashed` and
`solid` select dashed or solid lines. Note that `color` defaults to
`solid`, whereas `monochrome` defaults to `dashed`.  `enhanced` enables
enhanced text mode features (subscripts, superscripts and mixed fonts,
see `enhanced text` for more information).  `<fontspec>` is in the
format "<fontface>,<fontsize>", where "<fontface>" is the name of a
valid Windows font, and <fontsize> is the size of the font in points
and both components are optional.  Note that in previous versions of
gnuplot the `font` statement could be left out and <fontsize> could be
given as a number without double quotes. This is no longer supported.
`linewidth` and `fontscale` can be used to scale the width of lines and
the size of text.  *note title:: changes the title of the graph window.
*note size:: defines the width and height of the window in pixel and
*note position:: the origin of the window i.e. the position of the top
left corner on the screen (again in pixel). These options override any
default settings from the `wgnuplot.ini` file.

   Other options may be changed using the `graph-menu` or the
initialization file `wgnuplot.ini`.

   The Windows version normally terminates immediately as soon as the
end of any files given as command line arguments is reached (i.e. in
non-interactive mode), unless you specify `-` as the last command line
option.  It will also not show the text-window at all, in this mode,
only the plot.  By giving the optional argument `-persist` (same as for
gnuplot under x11; former Windows-only options `/noend` or `-noend` are
still accepted as well), will not close gnuplot. Contrary to gnuplot on
other operating systems, gnuplot's interactive command line is
accessible after the -persist option.

   The plot window remains open when the gnuplot terminal is changed
with a `set term` command. The plot window can be closed with `set term
windows close`.

   `gnuplot` supports different methods to create printed output on
Windows, see `windows printing`. The windows terminal supports data
exchange with other programs via clipboard and EMF files, see
`graph-menu`. You can also use the `terminal emf` to create EMF files.

-- GRAPH-MENU --

   The `gnuplot graph` window has the following options on a pop-up menu
accessed by pressing the right mouse button(*) or selecting `Options`
from the system menu:

   `Copy to Clipboard` copies a bitmap and an enhanced Metafile picture.

   `Save as EMF...` allows the user to save the current graph window as
enhanced metafile

   `Print...` prints the graphics windows using a Windows printer
driver and allows selection of the printer and scaling of the output.
The output produced by `Print` is not as good as that from `gnuplot`'s
own printer drivers. See also `windows printing`.

   `Bring to Top` when checked brings the graph window to the top after
every plot.

   `Color` when checked enables color linestyles.  When unchecked it
forces monochrome linestyles.

   `Double buffer` activates drawing into a memory buffer before
copying the graph to the screen. This avoids flickering e.g. during
animation and rotation of 3d graphs. See `mouse` and *note scrolling::.

   `Oversampling` doubles the size of the virtual canvas. It is scaled
down again for drawing to the screen. This gives smoother graphics but
requires more memory and computing time. It requires `double buffer`.

   `Antialiasing` selects smoothing of lines and edges. Note that this
slows down drawing.

   `Background...` sets the window background color.

   `Choose Font...` selects the font used in the graphics window.

   `Line Styles...` allows customization of the line colors and styles.

   `Update wgnuplot.ini` saves the current window locations, window
sizes, text window font, text window font size, graph window font,
graph window font size, background color and linestyles to the
initialization file `wgnuplot.ini`.

   (*) Note that this menu is only available by pressing the right
mouse button with `unset mouse`.

-- PRINTING --

   In order of preference, graphs may be printed in the following ways:

   `1.` Use the `gnuplot` command *note terminal:: to select a printer
and *note output:: to redirect output to a file.

   `2.` Select the `Print...` command from the `gnuplot graph` window.
An extra command `screendump` does this from the text window.

   `3.` If `set output "PRN"` is used, output will go to a temporary
file.  When you exit from `gnuplot` or when you change the output with
another *note output:: command, a dialog box will appear for you to
select a printer port.  If you choose OK, the output will be printed on
the selected port, passing unmodified through the print manager.  It is
possible to accidentally (or deliberately) send printer output meant
for one printer to an incompatible printer.

-- TEXT-MENU", /* FIXME: THIS IS NOT REALLY RELATED TO THE WINDOWS
DRIVER, BUT THE WINDOWS PLATFORM */ --

   The `gnuplot text` window has the following options on a pop-up menu
accessed by pressing the right mouse button or selecting `Options` from
the system menu:

   `Copy to Clipboard` copies marked text to the clipboard.

   `Paste` copies text from the clipboard as if typed by the user.

   `Choose Font...` selects the font used in the text window.

   `System Colors` when selected makes the text window honor the System
Colors set using the Control Panel.  When unselected, text is black or
blue on a white background.

   `Wrap long lines` when selected lines longer than the current window
width are wrapped.

   `Update wgnuplot.ini` saves the current settings to the
initialisation file `wgnuplot.ini`, which is located in the user's
application data directory.

-- WGNUPLOT.MNU", /* FIXME: THIS IS NOT REALLY RELATED TO THE WINDOWS
DRIVER, BUT THE WINDOWS PLATFORM */ --

   If the menu file `wgnuplot.mnu` is found in the same directory as
`gnuplot`, then the menu specified in `wgnuplot.mnu` will be loaded.
Menu commands:

      [Menu]      starts a new menu with the name on the following line.
      [EndMenu]   ends the current menu.
      [--]        inserts a horizontal menu separator.
      [|]         inserts a vertical menu separator.
      [Button]    puts the next macro on a push button instead of a menu.

   Macros take two lines with the macro name (menu entry) on the first
line and the macro on the second line.  Leading spaces are ignored.
Macro commands:

      [INPUT]     Input string with prompt terminated by [EOS] or {ENTER}
      [EOS]       End Of String terminator. Generates no output.
      [OPEN]      Get name of a file to open, with the title of the dialog
                  terminated by [EOS], followed by a default filename terminated
                  by [EOS] or {ENTER}.
      [SAVE]      Get name of a file to save.  Parameters like [OPEN]
      [DIRECTORY] Get name of a directory, with the title of the dialog
                  terminated by [EOS] or {ENTER}

   Macro character substitutions:

      {ENTER}     Carriage Return '\\r'
      {TAB}       Tab '\\011'
      {ESC}       Escape '\\033'
      {^A}        '\\001'
      ...
      {^_}        '\\031'

   Macros are limited to 256 characters after expansion.

-- WGNUPLOT.INI --

   The Windows text window and the `windows` terminal will read some of
their options from the `[WGNUPLOT]` section of `wgnuplot.ini`.  This
file is located in the user's application data directory. Here's a
sample `wgnuplot.ini` file:

           [WGNUPLOT]
           TextOrigin=0 0
           TextSize=640 150
           TextFont=Terminal,9
           TextWrap=1
           TextLines=400
           SysColors=0
           GraphOrigin=0 150
           GraphSize=640 330
           GraphFont=Arial,10
           GraphColor=1
           GraphToTop=1
           GraphDoublebuffer=1
           GraphOversampling=0
           GraphAntialiasing=1
           GraphBackground=255 255 255
           Border=0 0 0 0 0
           Axis=192 192 192 2 2
           Line1=0 0 255 0 0
           Line2=0 255 0 0 1
           Line3=255 0 0 0 2
           Line4=255 0 255 0 3
           Line5=0 0 128 0 4

   These settings apply to the wgnuplot text-window only."

   The `TextOrigin` and `TextSize` entries specify the location and
size of the text window.

   The `TextFont` entry specifies the text window font and size.

   The `TextWrap` entry selects wrapping of long text lines.

   The `TextLines` entry specifies the number of (unwrapped) lines the
internal buffer of the text window can hold. This value currently
cannot be changed from within wgnuplot.

   See `text-menu`.

   The `GraphFont` entry specifies the font name and size in points.

   The five numbers given in the `Border`, `Axis` and `Line` entries
are the `Red` intensity (0-255), `Green` intensity, `Blue` intensity,
`Color Linestyle` and `Mono Linestyle`.  `Linestyles` are 0=SOLID,
1=DASH, 2=DOT, 3=DASHDOT, 4=DASHDOTDOT.  In the sample `wgnuplot.ini`
file above, Line 2 is a green solid line in color mode, or a dashed
line in monochrome mode.  The default line width is 1 pixel.  If
`Linestyle` is negative, it specifies the width of a SOLID line in
pixels.  Line1 and any linestyle used with the `points` style must be
SOLID with unit width.

   See `graph-menu`."


File: gnuplot.info,  Node: wxt,  Next: x11,  Prev: windows,  Up: complete_list_of_terminals

4.1.0.62 wxt
............

The `wxt` terminal device generates output in a separate window. The
window is created by the wxWidgets library, where the 'wxt' comes from.
The actual drawing is done via cairo, a 2D graphics library, and pango,
a library for laying out and rendering text.

   Syntax:
             set term wxt {<n>}
                          {size <width>,<height>} {background <rgb_color>}
                          {{no}enhanced}
                          {font <font>} {fontscale <scale>}
                          {title "title"}
                          {dashed|solid} {dashlength <dl>}
                          {{no}persist}
                          {{no}raise}
                          {{no}ctrl}
                          {close}

   Multiple plot windows are supported: `set terminal wxt <n>` directs
the output to plot window number n.

   The default window title is based on the window number. This title
can also be specified with the keyword "title".

   Plot windows remain open even when the `gnuplot` driver is changed
to a different device.  A plot window can be closed by pressing the
letter 'q' while that window has input focus, by choosing `close` from
a window manager menu, or with `set term wxt <n> close`.

   The size of the plot area is given in pixels, it defaults to 640x384.
In addition to that, the actual size of the window also includes the
space reserved for the toolbar and the status bar.  When you resize a
window, the plot is immediately scaled to fit in the new size of the
window. Unlike other interactive terminals, the `wxt` terminal scales
the whole plot, including fonts and linewidths, and keeps its global
aspect ratio constant, leaving an empty space painted in gray.  If you
type *note replot::, click the *note replot:: icon in the terminal
toolbar or type a new `plot` command, the new plot will completely fit
in the window and the font size and the linewidths will be reset to
their defaults.

   The active plot window (the one selected by `set term wxt <n>`) is
interactive. Its behaviour is shared with other terminal types. See
`mouse` for details. It also has some extra icons, which are supposed
to be self-explanatory.

   This terminal supports an enhanced text mode, which allows font and
other formatting commands (subscripts, superscripts, etc.) to be
embedded in labels and other text strings. The enhanced text mode
syntax is shared with other gnuplot terminal types. See `enhanced` for
more details.

   <font> is in the format "FontFace,FontSize", i.e. the face and the
size comma-separated in a single string. FontFace is a usual font face
name, such as \'Arial\'. If you do not provide FontFace, the wxt
terminal will use \'Sans\'. FontSize is the font size, in points. If
you do not provide it, the wxt terminal will use a size of 10 points.
        For example :
           set term wxt font "Arial,12"
           set term wxt font "Arial" # to change the font face only
           set term wxt font ",12" # to change the font size only
           set term wxt font "" # to reset the font name and size

   The fonts are retrieved from the usual fonts subsystems. Under
Windows, those fonts are to be found and configured in the entry
"Fonts" of the control panel. Under UNIX, they are handled by
"fontconfig".

   Pango, the library used to layout the text, is based on utf-8. Thus,
the wxt terminal has to convert from your encoding to utf-8. The
default input encoding is based on your \'locale\'. If you want to use
another encoding, make sure gnuplot knows which one you are using. See
*note encoding:: for more details.

   Pango may give unexpected results with fonts that do not respect the
unicode mapping. With the Symbol font, for example, the wxt terminal
will use the map provided by http://www.unicode.org/ to translate
character codes to unicode.  Pango will do its best to find a font
containing this character, looking for your Symbol font, or other fonts
with a broad unicode coverage, like the DejaVu fonts. Note that "the
Symbol font" is to be understood as the Adobe Symbol font, distributed
with Acrobat Reader as "SY______.PFB".  Alternatively, the OpenSymbol
font, distributed with OpenOffice.org as "opens___.ttf", offers the
same characters. Microsoft has distributed a Symbol font
("symbol.ttf"), but it has a different character set with several
missing or moved mathematic characters. If you experience problems with
your default setup (if the demo enhancedtext.dem is not displayed
properly for example), you probably have to install one of the Adobe or
OpenOffice Symbol fonts, and remove the Microsoft one.  Other
non-conform fonts, such as "wingdings" have been observed working.

   The rendering of the plot can be altered with a dialog available
from the toolbar. To obtain the best output possible, the rendering
involves three mechanisms : antialiasing, oversampling and hinting.
Antialiasing allows to display non-horizontal and non-vertical lines
smoother.  Oversampling combined with antialiasing provides subpixel
accuracy, so that gnuplot can draw a line from non-integer coordinates.
This avoids wobbling effects on diagonal lines ('plot x' for example).
Hinting avoids the blur on horizontal and vertical lines caused by
oversampling. The terminal will snap these lines to integer coordinates
so that a one-pixel-wide line will actually be drawn on one and only
one pixel.

   By default, the window is raised to the top of your desktop when a
plot is drawn. This can be controlled with the keyword "raise".  The
keyword "persist" will prevent gnuplot from exiting before you
explicitely close all the plot windows.  Finally, by default the key
<space> raises the gnuplot console window, and 'q' closes the plot
window. The keyword "ctrl" allows you to replace those bindings by
<ctrl>+<space> and <ctrl>+'q', respectively.  These three keywords
(raise, persist and ctrl) can also be set and remembered between
sessions through the configuration dialog."


File: gnuplot.info,  Node: x11,  Next: xlib,  Prev: wxt,  Up: complete_list_of_terminals

4.1.0.63 x11
............

Syntax:
        set terminal x11 {<n> | window "<string>"}
                         {title "<string>"}
                         {{no}enhanced} {font <fontspec>}
                         {linewidth LW} {solid|dashed}
                         {{no}persist} {{no}raise} {{no}ctrlq}
                         {close}
                         {size XX,YY} {position XX,YY}
        set terminal x11 {reset}

   Multiple plot windows are supported: `set terminal x11 <n>` directs
the output to plot window number n.  If n is not 0, the terminal number
will be appended to the window title (unless a title has been supplied
manually) and the icon will be labeled `Gnuplot <n>`.  The active
window may be distinguished by a change in cursor (from default to
crosshair).

   The `x11` terminal can connect to X windows previously created by an
outside application via the option `window` followed by a string
containing the X ID for the window in hexadecimal format.  Gnuplot uses
that external X window as a container since X does not allow for
multiple clients selecting the ButtonPress event.  In this way,
gnuplot's mouse features work within the contained plot window.

        set term x11 window "220001e"

   The x11 terminal supports enhanced text mode (see `enhanced`),
subject to the available fonts. In order for font size commands
embedded in text to have any effect, the default x11 font must be
scalable. Thus the first example below will work as expected, but the
second will not.

        set term x11 enhanced font "arial,15"
        set title '{/=20 Big} Medium {/=5 Small}'

        set term x11 enhanced font "terminal-14"
        set title '{/=20 Big} Medium {/=5 Small}'

   Plot windows remain open even when the `gnuplot` driver is changed
to a different device.  A plot window can be closed by pressing the
letter q while that window has input focus, or by choosing `close` from
a window manager menu.  All plot windows can be closed by specifying
*note reset::, which actually terminates the subprocess which maintains
the windows (unless `-persist` was specified).  The `close` command can
be used to close individual plot windows by number.  However, after a
*note reset::, those plot windows left due to persist cannot be closed
with the command `close`.  A `close` without a number closes the
current active plot window.

   The gnuplot outboard driver, gnuplot_x11, is searched in a default
place chosen when the program is compiled.  You can override that by
defining the environment variable GNUPLOT_DRIVER_DIR to point to a
different location.

   Plot windows will automatically be closed at the end of the session
unless the `-persist` option was given.

   The options `persist` and *note raise:: are unset by default, which
means that the defaults (persist == no and raise == yes) or the command
line options -persist / -raise or the Xresources are taken.  If
[no]persist or [no]raise are specified, they will override command line
options and Xresources.  Setting one of these options takes place
immediately, so the behaviour of an already running driver can be
modified.  If the window does not get raised, see discussion in *note
raise::.

   The option `title "<title name>"` will supply the title name of the
window for the current plot window or plot window <n> if a number is
given.  Where (or if) this title is shown depends on your X window
manager.

   The size option can be used to set the size of the plot window.  The
size option will only apply to newly created windows.

   The position option can be used to set the position of the plot
window.  The position option will only apply to newly created windows.

   The size or aspect ratio of a plot may be changed by resizing the
`gnuplot` window.

   Linewidths and pointsizes may be changed from within `gnuplot` with
`set linestyle`.

   For terminal type `x11`, `gnuplot` accepts (when initialized) the
standard X Toolkit options and resources such as geometry, font, and
name from the command line arguments or a configuration file.  See the
X(1) man page (or its equivalent) for a description of such options.

   A number of other `gnuplot` options are available for the `x11`
terminal.  These may be specified either as command-line options when
`gnuplot` is invoked or as resources in the configuration file
".Xdefaults".  They are set upon initialization and cannot be altered
during a `gnuplot` session.  (except `persist` and *note raise::)

-- X11_FONTS --

   Upon initial startup, the default font is taken from the X11
resources as set in the system or user .Xdefaults file or on the
command line.

   Example:
           gnuplot*font: lucidasans-bold-12

   A new default font may be specified to the x11 driver from inside
gnuplot using
          `set term x11 font "<fontspec>"`

   The driver first queries the X-server for a font of the exact name
given.  If this query fails, then it tries to interpret <fontspec> as
"<font>,<size>,<slant>,<weight>" and to construct a full X11 font name
of the form
           -*-<font>-<weight>-<s>-*-*-<size>-*-*-*-*-*-<encoding>

      <font> is the base name of the font (e.g. Times or Symbol)
      <size> is the point size (defaults to 12 if not specified)
      <s> is `i` if <slant>=="italic" `o` if <slant>=="oblique" `r` otherwise
      <weight> is `medium` or `bold` if explicitly requested, otherwise `*`
      <encoding> is set based on the current character set (see *note encoding::).

   So `set term x11 font "arial,15,italic"` will be translated to
-*-arial-*-i-*-*-15-*-*-*-*-*-iso8859-1 (assuming default encoding).
The <size>, <slant>, and <weight> specifications are all optional.  If
you do not specify <slant> or <weight> then you will get whatever font
variant the font server offers first.  You may set a default enconding
via the corresponding X11 resource. E.g.
           gnuplot*encoding: iso8859-15

   The driver also recognizes some common PostScript font names and
replaces them with possible X11 or TrueType equivalents.  This same
sequence is used to process font requests from `set label`.

   If your gnuplot was built with configuration option
-enable-x11-mbfonts, you can specify multi-byte fonts by using the
prefix "mbfont:" on the font name. An additional font may be given,
separated by a semicolon.  Since multi-byte font encodings are
interpreted according to the locale setting, you must make sure that
the environmental variable LC_CTYPE is set to some appropriate locale
value such as ja_JP.eucJP, ko_KR.EUC, or zh_CN.EUC.

   Example:
           set term x11 font 'mbfont:kana14;k14'
                 # 'kana14' and 'k14' are Japanese X11 font aliases, and ';'
                 # is the separator of font names.
           set term x11 font 'mbfont:fixed,16,r,medium'
                 # <font>,<size>,<slant>,<weight> form is also usable.
           set title '(mb strings)' font 'mbfont:*-fixed-medium-r-normal--14-*'

   The same syntax applies to the default font in Xresources settings,
for example,
           gnuplot*font: \\
               mbfont:-misc-fixed-medium-r-normal--14-*-*-*-c-*-jisx0208.1983-0

   If gnuplot is built with -enable-x11-mbfonts, you can use two special
PostScript font names 'Ryumin-Light-*' and 'GothicBBB-Medium-*'
(standard Japanese PS fonts) without the prefix "mbfont:".

-- COMMAND-LINE_OPTIONS --

   In addition to the X Toolkit options, the following options may be
specified on the command line when starting `gnuplot` or as resources
in your ".Xdefaults" file (note that *note raise:: and `persist` can be
overridden later by `set term x11 [no]raise [no]persist)`:

      `-mono`     forces monochrome rendering on color displays.
      `-gray`     requests grayscale rendering on grayscale or color displays.
                  (Grayscale displays receive monochrome rendering by default.)
      `-clear`    requests that the window be cleared momentarily before a
                  new plot is displayed.
      `-tvtwm`    requests that geometry specifications for position of the
                  window be made relative to the currently displayed portion
                  of the virtual root.
      `-raise`    raises plot window after each plot
      `-noraise`  does not raise plot window after each plot
      `-noevents` does not process mouse and key events
      `-ctrlq   ` closes window on ctrl-q rather than q
      `-persist`  plot windows survive after main gnuplot program exits

   The options are shown above in their command-line syntax.  When
entered as resources in ".Xdefaults", they require a different syntax.

   Example:
           gnuplot*gray:  on
           gnuplot*ctrlq: on

   `gnuplot` also provides a command line option (`-pointsize <v>`) and
a resource, `gnuplot*pointsize: <v>`, to control the size of points
plotted with the `points` plotting style.  The value `v` is a real
number (greater than 0 and less than or equal to ten) used as a scaling
factor for point sizes.  For example, `-pointsize 2` uses points twice
the default size, and `-pointsize 0.5` uses points half the normal size.

   The `-noevents` switch disables all mouse and key event processing
(except for `q` and `<space>` for closing the window). This is useful
for programs which use the x11 driver independent of the gnuplot main
program.

   The `-ctrlq` switch changes the hot-key that closes a plot window
from `q` to `<ctrl>q`. This is useful is you are using the
keystroke-capture feature `pause mouse keystroke`, since it allows the
character `q` to be captured just as all other alphanumeric characters.
The `-ctrlq` switch similarly replaces the <space> hot-key with
<ctrl><space> for the same reason.

-- MONOCHROME_OPTIONS --

   For monochrome displays, `gnuplot` does not honor foreground or
background colors.  The default is black-on-white.  `-rv` or
`gnuplot*reverseVideo: on` requests white-on-black.

-- COLOR_RESOURCES --

   The X11 terminal honors the following resources (shown here with
their default values) or the greyscale resources.  The values may be
color names as listed in the X11 rgb.txt file on your system,
hexadecimal RGB color specifications (see X11 documentation), or a
color name followed by a comma and an `intensity` value from 0 to 1.
For example, `blue, 0.5` means a half intensity blue.

      gnuplot*background:  white
      gnuplot*textColor:   black
      gnuplot*borderColor: black
      gnuplot*axisColor:   black
      gnuplot*line1Color:  red
      gnuplot*line2Color:  green
      gnuplot*line3Color:  blue
      gnuplot*line4Color:  magenta
      gnuplot*line5Color:  cyan
      gnuplot*line6Color:  sienna
      gnuplot*line7Color:  orange
      gnuplot*line8Color:  coral

   The command-line syntax for these is simple only for background,
which maps directly to the usual X11 toolkit option "-bg".  All others
can only be set on the command line by use of the generic "-xrm"
resource override option

   Examples:

           gnuplot -background coral

   to change the background color.

           gnuplot -xrm 'gnuplot*line1Color:blue'

   to override the first linetype color.

-- GRAYSCALE_RESOURCES --

   When `-gray` is selected, `gnuplot` honors the following resources
for grayscale or color displays (shown here with their default values).
Note that the default background is black.

      gnuplot*background: black
      gnuplot*textGray:   white
      gnuplot*borderGray: gray50
      gnuplot*axisGray:   gray50
      gnuplot*line1Gray:  gray100
      gnuplot*line2Gray:  gray60
      gnuplot*line3Gray:  gray80
      gnuplot*line4Gray:  gray40
      gnuplot*line5Gray:  gray90
      gnuplot*line6Gray:  gray50
      gnuplot*line7Gray:  gray70
      gnuplot*line8Gray:  gray30

-- LINE_RESOURCES --

   `gnuplot` honors the following resources for setting the width (in
pixels) of plot lines (shown here with their default values.)  0 or 1
means a minimal width line of 1 pixel width.  A value of 2 or 3 may
improve the appearance of some plots.

      gnuplot*borderWidth: 2
      gnuplot*axisWidth:   0
      gnuplot*line1Width:  0
      gnuplot*line2Width:  0
      gnuplot*line3Width:  0
      gnuplot*line4Width:  0
      gnuplot*line5Width:  0
      gnuplot*line6Width:  0
      gnuplot*line7Width:  0
      gnuplot*line8Width:  0

   `gnuplot` honors the following resources for setting the dash style
used for plotting lines.  0 means a solid line.  A two-digit number
`jk` (`j` and `k` are >= 1 and <= 9) means a dashed line with a
repeated pattern of `j` pixels on followed by `k` pixels off.  For
example, '16' is a dotted line with one pixel on followed by six pixels
off.  More elaborate on/off patterns can be specified with a four-digit
value.  For example, '4441' is four on, four off, four on, one off.
The default values shown below are for monochrome displays or
monochrome rendering on color or grayscale displays.  Color displays
default to dashed:off

      gnuplot*dashed:       off
      gnuplot*borderDashes:   0
      gnuplot*axisDashes:    16
      gnuplot*line1Dashes:    0
      gnuplot*line2Dashes:   42
      gnuplot*line3Dashes:   13
      gnuplot*line4Dashes:   44
      gnuplot*line5Dashes:   15
      gnuplot*line6Dashes: 4441
      gnuplot*line7Dashes:   42
      gnuplot*line8Dashes:   13

   , "

-- X11 PM3D_RESOURCES --

   Choosing the appropriate visual class and number of colors is a
crucial point in X11 applications and a bit awkward, since X11 supports
six visual types in different depths.

   By default `gnuplot` uses the default visual of the screen. The
number of colors which can be allocated depends on the visual class
chosen. On a visual class with a depth > 12bit, gnuplot starts with a
maximal number of 0x200 colors.  On a visual class with a depth > 8bit
(but <= 12 bit) the maximal number of colors is 0x100, on <= 8bit
displays the maximum number of colors is 240 (16 are left for line
colors).

   Gnuplot first starts to allocate the maximal number of colors as
stated above.  If this fails, the number of colors is reduced by the
factor 2 until gnuplot gets all colors which are requested. If dividing
`maxcolors` by 2 repeatedly results in a number which is smaller than
`mincolors` `gnuplot` tries to install a private colormap. In this case
the window manager is responsible for swapping colormaps when the
pointer is moved in and out the x11 driver's window.

   The default for `mincolors` is maxcolors / (num_colormaps > 1 ? 2 :
8), where num_colormaps is the number of colormaps which are currently
used by gnuplot (usually 1, if only one x11 window is open).

   Some systems support multiple (different) visual classes together on
one screen. On these systems it might be necessary to force gnuplot to
use a specific visual class, e.g. the default visual might be 8bit
PseudoColor but the screen would also support 24bit TrueColor which
would be the preferred choice.

   The information about an Xserver's capabilities can be obtained with
the program `xdpyinfo`.  For the visual names below you can choose one
of StaticGray, GrayScale, StaticColor, PseudoColor, TrueColor,
DirectColor.  If an Xserver supports a requested visual type at
different depths, `gnuplot` chooses the visual class with the highest
depth (deepest).  If the requested visual class matches the default
visual and multiple classes of this type are supported, the default
visual is preferred.

   Example: on an 8bit PseudoColor visual you can force a private color
map by specifying `gnuplot*maxcolors: 240` and `gnuplot*mincolors: 240`.

      gnuplot*maxcolors:  <integer>
      gnuplot*mincolors:  <integer>
      gnuplot*visual:     <visual name>

   , "

-- X11 OTHER_RESOURCES --

   By default the contents of the current plot window are exported to
the X11 clipboard in response to X events in the window. Setting the
resource 'gnuplot*exportselection' to 'off' or 'false' will disable
this.

   By default text rotation is done using a method that is fast, but can
corrupt nearby colors depending on the background.  If this is a
problem, you can set the resource 'gnuplot.fastrotate' to 'off'

      gnuplot*exportselection:  off
      gnuplot*fastrotate:  on
      gnuplot*ctrlq:  off


File: gnuplot.info,  Node: xlib,  Prev: x11,  Up: complete_list_of_terminals

4.1.0.64 xlib
.............

The `xlib` terminal driver supports the X11 Windows System.  It
generates gnuplot_x11 commands, but sends them to the output file
specified by `set output '<filename>'`. `set term x11` is equivalent to
`set output "|gnuplot_x11 -noevents"; set term xlib`.  `xlib` takes the
same set of options as `x11`."

* Menu:

* Bugs::


File: gnuplot.info,  Node: Bugs,  Next: Concept_Index,  Prev: Terminal_types,  Up: Top

5 Bugs
******

Please e-mail bug reports to the gnuplot-bugs mailing list or upload
the report to the gnuplot web site on SourceForge.  Please give
complete information on the version of gnuplot you are using and, if
possible, a test script that demonstrates the bug.  See
`seeking-assistance`.

* Menu:

* known_limitations::
* External_libraries::


File: gnuplot.info,  Node: known_limitations,  Next: External_libraries,  Prev: Bugs,  Up: Bugs

5.1 known limitations
=====================

It is not possible to use in-line data (e.g. plot '-' ...) inside the
curly brackets of a `do` or `while` loop.

   Floating point exceptions (floating point number too large/small,
divide by zero, etc.) may occasionally be generated by user defined
functions.  Some of the demos in particular may cause numbers to exceed
the floating point range.  Whether the system ignores such exceptions
(in which case `gnuplot` labels the corresponding point as undefined)
or aborts `gnuplot` depends on the compiler/runtime environment.

   The gamma, bessel, and erf functions do not work for complex
arguments.

   Coordinates specified as "time" wrap at 24 hours.

   The 'nohidden3d' option that is supposed to exempt individual plots
from the global property 'set hidden3d' does not work for parametric
curves.

   X11 terminal: It is difficult to select UTF-8 fonts.  The program
does not track the true aspect ratio of the x11 terminal window.  In
order for commands such as "set size ratio" to work, the x11 window
must itself have equal height and width.  Only one color palette at a
time is active for any given x11 plot window.  This means that
multiplots whose constituent plots use different palettes will not
display correctly in x11.

   Qt terminal: If the local qt environment does not support "opengl"
as a rendering mode then display of polygons and surfaces can be very
slow.


File: gnuplot.info,  Node: External_libraries,  Prev: known_limitations,  Up: Bugs

5.2 External libraries
======================

External library GD (used by PNG/JPEG/GIF drivers): Versions of libgd
through 2.0.33 contain various bugs in mapping the characters of
Adobe's Symbol font.  Also it is possible to trigger a library segfault
if an anti-aliased line crosses an upper corner of the canvas.

   External library PDFlib (used by PDF driver): Gnuplot can be linked
against libpdf versions 4, 5, or 6. However, these versions differ in
their handling of piped I/O.  Therefore gnuplot scripts using piped
output to PDF may work only for some versions of PDFlib.

   External library svgalib (used by linux and vgagl driver): Requires
gnuplot to be suid root (bad!) and has many bugs that are specific to
the video card or graphics driver used in X11.

   Internationalization (locale settings): Gnuplot uses the C runtime
library routine setlocale() to control locale-specific formatting of
input and output number, times, and date strings.  The locales
available, and the level of support for locale features such as
"thousands' grouping separator", depend on the internationalization
support provided by your individual machine.


File: gnuplot.info,  Node: Concept_Index,  Next: Command_Index,  Prev: Bugs,  Up: Top

Concept Index
*************

[index]
* Menu:

* .gnuplot:                              Start-up_(initialization).
                                                              (line   6)
* 3D:                                    3D_(surface)_plots.  (line   6)
* abs:                                   abs.                 (line   6)
* acos:                                  acos.                (line   6)
* acosh:                                 acosh.               (line   6)
* acsplines:                             smooth.              (line  41)
* aed512:                                aed767.              (line   6)
* aed767:                                aed767.              (line   6)
* aifm:                                  aifm.                (line   6)
* airy:                                  airy.                (line   6)
* angles:                                angles.              (line   6)
* aqua:                                  aqua.                (line   6)
* Aqua:                                  aqua.                (line   6)
* arg:                                   arg.                 (line   6)
* arrow:                                 arrow.               (line   6)
* arrowstyle:                            set_style_arrow.     (line   6)
* asin:                                  asin.                (line   6)
* asinh:                                 asinh.               (line   6)
* atan:                                  atan.                (line   6)
* atan2:                                 atan2.               (line   6)
* atanh:                                 atanh.               (line   6)
* automated:                             automated_iteration_over_multiple_columns.
                                                              (line   6)
* autoscale:                             autoscale.           (line   6)
* avs:                                   filetype.            (line  22)
* axes <1>:                              Coordinates.         (line   6)
* axes <2>:                              axes.                (line   6)
* axes:                                  Plotting.            (line  23)
* background:                            background_color.    (line   6)
* backquotes:                            Substitution_of_system_commands_in_backquotes.
                                                              (line   6)
* bars:                                  bars.                (line   6)
* batch/interactive:                     Batch/Interactive_Operation.
                                                              (line   6)
* be:                                    be.                  (line   6)
* BE:                                    be.                  (line   6)
* besj0:                                 besj0.               (line   6)
* besj1:                                 besj1.               (line   6)
* bessel:                                known_limitations.   (line   9)
* besy0:                                 besy0.               (line   6)
* besy1:                                 besy1.               (line   6)
* bezier:                                smooth.              (line  67)
* bgnd:                                  background_color.    (line   6)
* binary:                                binary.              (line   6)
* bind <1>:                              bind_.               (line   6)
* bind <2>:                              reset.               (line  20)
* bind:                                  bind.                (line   6)
* bitgraph:                              tek40.               (line   6)
* bitwise operators:                     Binary.              (line  32)
* bmargin:                               bmargin.             (line   6)
* border:                                border.              (line   6)
* boxerrorbars:                          boxerrorbars.        (line   6)
* boxes:                                 boxes.               (line   6)
* boxplot:                               boxplot.             (line   6)
* boxwidth:                              boxwidth.            (line   6)
* boxxyerrorbars:                        boxxyerrorbars.      (line   6)
* branch:                                multi-branch.        (line   6)
* bugs:                                  Bugs.                (line   6)
* call:                                  call.                (line   6)
* candlesticks:                          candlesticks.        (line   6)
* canvas:                                Canvas_size.         (line   6)
* cbdata:                                cbdata.              (line   6)
* cbdtics:                               cbdtics.             (line   6)
* cblabel:                               cblabel.             (line   6)
* cbmtics:                               cbmtics.             (line   6)
* cbrange:                               cbrange.             (line   6)
* cbtics:                                cbtics.              (line   6)
* cd:                                    cd.                  (line   6)
* ceil:                                  ceil.                (line   6)
* cgi:                                   cgi.                 (line   6)
* cgm:                                   cgm.                 (line   6)
* circle:                                circle.              (line   6)
* circles:                               circles.             (line   6)
* clabel:                                clabel.              (line   6)
* clear:                                 clear.               (line   6)
* clip:                                  clip.                (line   6)
* cnormal:                               smooth.              (line 105)
* cntrparam:                             cntrparam.           (line   6)
* color_resources:                       x11.                 (line 217)
* colorbox:                              color_box.           (line   6)
* colornames:                            colornames.          (line   6)
* colors <1>:                            linetypes.           (line  33)
* colors <2>:                            rgbformulae.         (line   6)
* colors <3>:                            defined_.            (line   6)
* colors <4>:                            linetypes.           (line   6)
* colors:                                colorspec.           (line   6)
* colorspec:                             colorspec.           (line   6)
* column <1>:                            column.              (line   6)
* column:                                using.               (line  27)
* columnhead <1>:                        using.               (line  29)
* columnhead:                            columnhead.          (line   6)
* columnheader <1>:                      key.                 (line  91)
* columnheader <2>:                      title.               (line   6)
* columnheader:                          Datastrings.         (line  31)
* command-line-editing:                  Command-line-editing.
                                                              (line   6)
* command-line-options:                  x11.                 (line 164)
* commands:                              Commands.            (line   6)
* comments:                              Comments.            (line   6)
* commentschars:                         set_datafile_commentschars.
                                                              (line   6)
* compatibility:                         Backwards_compatibility.
                                                              (line   6)
* context:                               context.             (line   6)
* contour:                               contour.             (line   6)
* coordinates:                           Coordinates.         (line   6)
* copyright:                             Copyright.           (line   6)
* corel:                                 corel.               (line   6)
* cos:                                   cos.                 (line   6)
* cosh:                                  cosh.                (line   6)
* csplines:                              smooth.              (line  72)
* cubehelix:                             cubehelix.           (line   6)
* cumulative <1>:                        smooth.              (line  96)
* cumulative:                            New_smoothing_algorithms.
                                                              (line   6)
* cycle:                                 linetype.            (line  55)
* data:                                  data.                (line   6)
* data-file:                             data.                (line   6)
* datafile:                              data.                (line   6)
* datastrings:                           Datastrings.         (line   6)
* date_specifiers:                       time/date_specifiers.
                                                              (line   6)
* debug:                                 debug.               (line   6)
* decimalsign:                           decimalsign.         (line   6)
* defined:                               defined.             (line   6)
* degrees:                               angles.              (line   6)
* depthorder:                            scanorder.           (line   6)
* dgrid3d:                               dgrid3d.             (line   6)
* division:                              Expressions.         (line  16)
* do:                                    Do.                  (line   6)
* dospc:                                 dospc.               (line   6)
* dots:                                  dots.                (line   6)
* dpu414:                                epson_180dpi.        (line   6)
* dumb:                                  dumb.                (line   6)
* dummy:                                 dummy.               (line   6)
* dx:                                    keywords.            (line  42)
* dxf:                                   dxf.                 (line   6)
* dxy800a:                               dxy800a.             (line   6)
* dy:                                    keywords.            (line  42)
* edf:                                   filetype.            (line  30)
* editing:                               Command-line-editing.
                                                              (line   6)
* eepic:                                 eepic.               (line   6)
* ehf:                                   filetype.            (line  30)
* ellipse:                               ellipse.             (line   6)
* ellipses:                              ellipses.            (line   6)
* elliptic integrals:                    elliptic_integrals.  (line   6)
* emf:                                   emf.                 (line   6)
* emtex:                                 latex.               (line   6)
* emxvesa:                               emxvga.              (line   6)
* emxvga:                                emxvga.              (line   6)
* encoding:                              encoding.            (line   6)
* encodings:                             encoding.            (line   6)
* enhanced:                              Enhanced_text_mode.  (line   6)
* environment:                           Environment.         (line   6)
* eps:                                   postscript__(also_encapsulated_postscript_*.eps).
                                                              (line   6)
* epscairo:                              epscairo.            (line   6)
* epson_180dpi:                          epson_180dpi.        (line   6)
* epson_60dpi:                           epson_180dpi.        (line   6)
* epson_lx800:                           epson_180dpi.        (line   6)
* equal_axes:                            equal_axes.          (line   6)
* erf:                                   erf.                 (line   6)
* erfc:                                  erfc.                (line   6)
* error state <1>:                       Gnuplot-defined_variables.
                                                              (line  23)
* error state:                           reset.               (line  17)
* errorbars:                             errorbars.           (line   6)
* errorlines:                            errorlines.          (line   6)
* errors:                                Gnuplot-defined_variables.
                                                              (line  23)
* evaluate:                              evaluate.            (line   6)
* every:                                 every.               (line   6)
* example:                               example_datafile.    (line   6)
* examples:                              using.               (line  75)
* excl:                                  excl.                (line   6)
* exists <1>:                            exists.              (line   6)
* exists:                                Substitution_of_string_variables_as_macros.
                                                              (line   6)
* exit:                                  exit.                (line   6)
* exp:                                   exp.                 (line   6)
* expint:                                expint.              (line   6)
* exponentiation:                        Binary.              (line  32)
* expressions:                           Expressions.         (line   6)
* factorial:                             Unary.               (line  16)
* failsafe:                              image_failsafe.      (line   6)
* FAQ:                                   Seeking-assistance.  (line   6)
* faq:                                   Seeking-assistance.  (line   6)
* fig:                                   fig.                 (line   6)
* file:                                  data.                (line   6)
* filetype:                              filetype.            (line   6)
* filledcurves:                          filledcurves.        (line   6)
* fillsteps:                             fillsteps.           (line   6)
* fillstyle:                             set_style_fill.      (line   6)
* financebars:                           financebars.         (line   6)
* fit:                                   fit.                 (line   6)
* fit_parameters:                        adjustable_parameters.
                                                              (line   6)
* fitting:                               short_introduction.  (line   6)
* floating point exceptions <1>:         known_limitations.   (line   9)
* floating point exceptions:             set_datafile_nofpe_trap.
                                                              (line   6)
* floor:                                 floor.               (line   6)
* flush:                                 scanorder.           (line   6)
* fontpath:                              fontpath.            (line   6)
* fonts <1>:                             x11.                 (line 102)
* fonts <2>:                             cairo_(pdfcairo.     (line   6)
* fonts <3>:                             gd_(png.             (line   6)
* fonts <4>:                             postscript__(also_encapsulated_postscript_*.eps).
                                                              (line   6)
* fonts:                                 Fonts.               (line   6)
* format:                                format_.             (line   6)
* format_specifiers:                     format_specifiers.   (line   6)
* fortran:                               set_datafile_fortran.
                                                              (line   6)
* fpe_trap:                              set_datafile_nofpe_trap.
                                                              (line   6)
* frequency:                             smooth.              (line  88)
* fsteps:                                fsteps.              (line   6)
* functions:                             functions.           (line   6)
* gamma <1>:                             known_limitations.   (line   9)
* gamma:                                 gamma.               (line   6)
* gamma-correction:                      gamma_correction.    (line   6)
* gd:                                    gd_(png.             (line   6)
* geomean:                               color_assignment.    (line   6)
* ggi:                                   ggi.                 (line   6)
* gif:                                   gd_(png.             (line   6)
* glossary:                              Glossary.            (line   6)
* gnuplot:                               gnuplot.             (line   6)
* gpic:                                  gpic.                (line   6)
* gprintf:                               gprintf_.            (line   6)
* GPVAL:                                 Gnuplot-defined_variables.
                                                              (line   6)
* graph-menu:                            windows.             (line  68)
* grass:                                 grass.               (line   6)
* grayscale_resources:                   x11.                 (line 254)
* grid:                                  grid.                (line   6)
* grid_data:                             grid_data.           (line   6)
* guidelines:                            practical_guidelines.
                                                              (line   6)
* hcgi:                                  cgi.                 (line   6)
* heatmap:                               image.               (line  12)
* help:                                  help.                (line   6)
* help-desk:                             Seeking-assistance.  (line   6)
* hidden3d:                              hidden3d.            (line   6)
* histeps:                               histeps.             (line   6)
* histograms:                            histograms.          (line   6)
* history:                               history.             (line   6)
* historysize:                           historysize.         (line   6)
* hotkey:                                bind.                (line   6)
* hotkeys:                               bind.                (line   6)
* hp2623a:                               hp2623a.             (line   6)
* hp2648:                                hp2648.              (line   6)
* hp500c:                                hp500c.              (line   6)
* hpdj:                                  hpljii.              (line   6)
* hpgl:                                  hpgl.                (line   6)
* hpljii:                                hpljii.              (line   6)
* hppj:                                  hppj.                (line   6)
* ibeta:                                 ibeta.               (line   6)
* if:                                    if.                  (line   6)
* if-old:                                if-old.              (line   6)
* igamma:                                igamma.              (line   6)
* imag:                                  imag.                (line   6)
* image:                                 image.               (line   6)
* imagen:                                imagen.              (line   6)
* impulses:                              impulses.            (line   6)
* index:                                 index.               (line   6)
* initialization:                        Start-up_(initialization).
                                                              (line   6)
* int:                                   int.                 (line   6)
* internationalization:                  External_libraries.  (line   6)
* interval:                              set_style_line.      (line   6)
* introduction:                          Introduction.        (line   6)
* inverf:                                inverf.              (line   6)
* invnorm:                               invnorm.             (line   6)
* isosamples:                            isosamples.          (line   6)
* iterate:                               iteration.           (line   6)
* iteration <1>:                         unset.               (line   6)
* iteration <2>:                         iteration_.          (line   6)
* iteration <3>:                         iteration.           (line   6)
* iteration:                             set-show.            (line  20)
* jpeg:                                  gd_(png.             (line   6)
* kc-tek40xx:                            tek40.               (line   6)
* kdensity <1>:                          New_smoothing_algorithms.
                                                              (line   6)
* kdensity:                              smooth.              (line 117)
* kdensity2d:                            dgrid3d.             (line   6)
* key:                                   key.                 (line   6)
* km-tek40xx:                            tek40.               (line   6)
* kyo:                                   kyo.                 (line   6)
* label:                                 label.               (line   6)
* labels <1>:                            labels.              (line   6)
* labels:                                mouse.               (line  52)
* lambertw:                              lambertw.            (line   6)
* latex:                                 latex.               (line   6)
* lc:                                    colorspec.           (line   6)
* least-squares:                         fit.                 (line   6)
* legend:                                key.                 (line   6)
* lgamma:                                lgamma.              (line   6)
* libgd:                                 External_libraries.  (line   6)
* license:                               Copyright.           (line   6)
* line-editing:                          Command-line-editing.
                                                              (line   6)
* line_resources:                        x11.                 (line 273)
* linecolor:                             colorspec.           (line   6)
* lines:                                 lines.               (line   6)
* linespoints <1>:                       set_style_line.      (line   6)
* linespoints:                           linespoints.         (line   6)
* linestyle:                             set_style_line.      (line   6)
* linetype:                              linetype.            (line   6)
* linetypes:                             linetypes.           (line   6)
* linewidth:                             set_style_line.      (line   6)
* linux:                                 linux.               (line   6)
* lmargin:                               lmargin.             (line   6)
* load:                                  load.                (line   6)
* loadpath:                              loadpath.            (line   6)
* locale <1>:                            decimalsign.         (line   6)
* locale <2>:                            locale.              (line   6)
* locale:                                External_libraries.  (line   6)
* log:                                   log.                 (line   6)
* log10:                                 log10.               (line   6)
* logscale:                              logscale.            (line   6)
* lower:                                 lower.               (line   6)
* lp:                                    linespoints.         (line   6)
* lua:                                   lua.                 (line   6)
* macintosh:                             macintosh.           (line   6)
* macros:                                Substitution_of_string_variables_as_macros.
                                                              (line   6)
* mapping:                               mapping.             (line   6)
* margin:                                margin.              (line   6)
* Marquardt:                             fit.                 (line   6)
* max:                                   color_assignment.    (line   6)
* mean:                                  color_assignment.    (line   6)
* median:                                color_assignment.    (line   6)
* metafont:                              mf.                  (line   6)
* metapost:                              mp.                  (line   6)
* mf:                                    mf.                  (line   6)
* mif:                                   mif.                 (line   6)
* min:                                   color_assignment.    (line   6)
* missing:                               set_datafile_missing.
                                                              (line   6)
* mixing_macros_backquotes:              String_variables.    (line   6)
* modulo:                                Binary.              (line  32)
* monochrome_options:                    x11.                 (line 211)
* mouse:                                 mouse.               (line   6)
* mouseformat:                           mouseformat.         (line   6)
* mousewheel:                            scrolling.           (line   6)
* mousing:                               mouse.               (line   6)
* mp:                                    mp.                  (line   6)
* multi-branch:                          multi-branch.        (line   6)
* multiplot:                             multiplot.           (line   6)
* mx2tics:                               mx2tics.             (line   6)
* mxtics:                                mxtics.              (line   6)
* my2tics:                               my2tics.             (line   6)
* mytics:                                mytics.              (line   6)
* mztics:                                mztics.              (line   6)
* NaN <1>:                               User-defined_variables_and_functions.
                                                              (line  36)
* NaN <2>:                               Expressions.         (line  29)
* NaN:                                   using.               (line 100)
* nec_cp6:                               epson_180dpi.        (line   6)
* negation:                              Unary.               (line  16)
* new-features:                          New_features.        (line   6)
* newhistogram:                          newhistogram.        (line   6)
* NeXT:                                  Openstep_(next).     (line   8)
* next:                                  next.                (line   6)
* NeXT:                                  next.                (line   6)
* next:                                  Openstep_(next).     (line   6)
* noarrow:                               arrow.               (line   6)
* noautoscale:                           autoscale.           (line   6)
* noborder:                              border.              (line   6)
* nocbdtics:                             cbdtics.             (line   6)
* nocbmtics:                             cbmtics.             (line   6)
* nocbtics:                              cbtics.              (line   6)
* noclip:                                clip.                (line   6)
* nocontour:                             contour.             (line   6)
* nodgrid3d:                             dgrid3d.             (line   6)
* nofpe_trap:                            set_datafile_nofpe_trap.
                                                              (line   6)
* nogrid:                                grid.                (line   6)
* nohidden3d <1>:                        known_limitations.   (line   9)
* nohidden3d:                            hidden3d.            (line   6)
* nohistorysize:                         historysize.         (line   6)
* nokey:                                 key.                 (line   6)
* nolabel:                               label.               (line   6)
* nologscale:                            logscale.            (line   6)
* nomouse:                               mouse.               (line   6)
* nomultiplot:                           multiplot.           (line   6)
* nomx2tics:                             mx2tics.             (line   6)
* nomxtics:                              mxtics.              (line   6)
* nomy2tics:                             my2tics.             (line   6)
* nomytics:                              mytics.              (line   6)
* nomztics:                              mztics.              (line   6)
* nonuniform:                            matrix.              (line  24)
* nooffsets:                             offsets.             (line   6)
* noparametric:                          parametric_.         (line   6)
* nopolar:                               polar_.              (line   6)
* norm:                                  norm.                (line   6)
* nosurface:                             surface.             (line   6)
* notimestamp:                           timestamp.           (line   6)
* nox2dtics:                             x2dtics.             (line   6)
* nox2mtics:                             x2mtics.             (line   6)
* nox2tics:                              x2tics.              (line   6)
* nox2zeroaxis:                          x2zeroaxis.          (line   6)
* noxdtics:                              xdtics.              (line   6)
* noxmtics:                              xmtics.              (line   6)
* noxtics:                               xtics.               (line   6)
* noxzeroaxis:                           xzeroaxis.           (line   6)
* noy2dtics:                             y2dtics.             (line   6)
* noy2mtics:                             y2mtics.             (line   6)
* noy2tics:                              y2tics.              (line   6)
* noy2zeroaxis:                          y2zeroaxis.          (line   6)
* noydtics:                              ydtics.              (line   6)
* noymtics:                              ymtics.              (line   6)
* noytics:                               ytics.               (line   6)
* noyzeroaxis:                           yzeroaxis.           (line   6)
* nozdtics:                              zdtics.              (line   6)
* nozmtics:                              zmtics.              (line   6)
* noztics:                               ztics.               (line   6)
* nozzeroaxis:                           zzeroaxis.           (line   6)
* object:                                object.              (line   6)
* offsets:                               offsets.             (line   6)
* okidata:                               epson_180dpi.        (line   6)
* one's complement:                      Unary.               (line  16)
* openstep:                              Openstep_(next).     (line   6)
* Openstep:                              Openstep_(next).     (line   6)
* OpenStep:                              Openstep_(next).     (line   6)
* operator precedence:                   Unary.               (line  16)
* operators:                             Operators.           (line   6)
* origin:                                origin.              (line   6)
* output:                                output.              (line   6)
* palette:                               palette.             (line   6)
* parametric:                            parametric_.         (line   6)
* pause:                                 pause.               (line   6)
* pbm:                                   pbm.                 (line   6)
* pcl5:                                  hpgl.                (line   6)
* pdf <1>:                               pdf.                 (line   6)
* pdf <2>:                               External_libraries.  (line   6)
* pdf:                                   cairo_(pdfcairo.     (line   6)
* pi:                                    User-defined_variables_and_functions.
                                                              (line  36)
* plot:                                  plot.                (line   6)
* plotting:                              Plotting.            (line   6)
* pm3d:                                  pm3d.                (line   6)
* pm3d_resources:                        x11.                 (line 316)
* png <1>:                               gd_(png.             (line   6)
* png <2>:                               png_.                (line   6)
* png:                                   cairo_(pdfcairo.     (line   6)
* pointinterval <1>:                     linespoints.         (line   6)
* pointinterval:                         set_style_line.      (line   6)
* pointintervalbox:                      pointintervalbox.    (line   6)
* points:                                points.              (line   6)
* pointsize:                             pointsize.           (line   6)
* polar:                                 polar_.              (line   6)
* polygon:                               polygon.             (line   6)
* pop:                                   terminal.            (line   6)
* postscript:                            postscript__(also_encapsulated_postscript_*.eps).
                                                              (line   6)
* practical_guidelines:                  practical_guidelines.
                                                              (line   6)
* prescribe:                             kyo.                 (line   6)
* print:                                 print.               (line   6)
* printing:                              windows.             (line 115)
* projection:                            2D_projection_(set_view_map).
                                                              (line   6)
* psdir:                                 psdir.               (line   6)
* pseudocolumns:                         using.               (line 134)
* pstricks:                              pstricks.            (line   6)
* punctuation:                           Syntax.              (line   6)
* push:                                  terminal.            (line   6)
* pwd:                                   pwd.                 (line   6)
* qms:                                   qms.                 (line   6)
* quit:                                  quit.                (line   6)
* quotes:                                Quote_Marks.         (line   6)
* raise:                                 raise.               (line   6)
* rand <1>:                              Random_number_generator.
                                                              (line   6)
* rand:                                  rand.                (line   6)
* random:                                Random_number_generator.
                                                              (line   6)
* range-frame:                           xtics_rangelimited.  (line   6)
* rangelimited:                          xtics_rangelimited.  (line   6)
* ranges:                                ranges.              (line   6)
* ratio:                                 size.                (line   6)
* raxis:                                 raxis.               (line   6)
* real:                                  real.                (line   6)
* rectangle:                             rectangle.           (line   6)
* refresh:                               refresh.             (line   6)
* regis:                                 regis.               (line   6)
* replot:                                replot.              (line   6)
* reread:                                reread.              (line   6)
* reset:                                 reset.               (line   6)
* restore:                               xrange.              (line   6)
* rgbalpha:                              image.               (line   6)
* rgbcolor:                              colorspec.           (line   6)
* rgbformulae:                           rgbformulae.         (line   6)
* rgbimage:                              image.               (line   6)
* rmargin:                               rmargin.             (line   6)
* rrange:                                rrange.              (line   6)
* rtics:                                 rtics.               (line   6)
* samples:                               samples.             (line   6)
* save:                                  save.                (line   6)
* sbezier:                               smooth.              (line  77)
* scansautomatic:                        scanorder.           (line   6)
* scansbackward:                         scanorder.           (line   6)
* scansforward:                          scanorder.           (line   6)
* screendump:                            windows.             (line 115)
* scrolling:                             scrolling.           (line   6)
* seeking-assistance:                    Seeking-assistance.  (line   6)
* selanar:                               tek40.               (line   6)
* separator:                             set_datafile_separator.
                                                              (line   6)
* set:                                   set-show.            (line   6)
* sgn:                                   sgn.                 (line   6)
* shell:                                 shell.               (line   6)
* show:                                  set-show.            (line   6)
* sin:                                   sin.                 (line   6)
* sinh:                                  sinh.                (line   6)
* size:                                  size.                (line   6)
* SJIS:                                  encoding.            (line   6)
* skip:                                  example_datafile.    (line  22)
* smooth:                                smooth.              (line   6)
* special-filenames:                     special-filenames.   (line   6)
* specify:                               Syntax.              (line   6)
* splot:                                 splot.               (line   6)
* sprintf:                               sprintf.             (line   6)
* sqrt:                                  sqrt.                (line   6)
* starc:                                 epson_180dpi.        (line   6)
* start:                                 Start-up_(initialization).
                                                              (line   6)
* start-up:                              Start-up_(initialization).
                                                              (line   6)
* starting_values:                       starting_values.     (line   6)
* startup:                               Start-up_(initialization).
                                                              (line   6)
* statistical_overview:                  statistical_overview.
                                                              (line   6)
* statistics:                            stats_(Statistical_Summary).
                                                              (line   6)
* stats:                                 stats_(Statistical_Summary).
                                                              (line   6)
* steps:                                 steps.               (line   6)
* strcol:                                stringcolumn.        (line   6)
* strftime:                              strftime.            (line   6)
* string operators:                      Binary.              (line  32)
* stringcolumn:                          stringcolumn.        (line   6)
* strings:                               String_constants_and_string_variables.
                                                              (line   6)
* strlen:                                strlen.              (line   6)
* strptime:                              strptime.            (line   6)
* strstrt:                               strstrt.             (line   6)
* style:                                 with.                (line   6)
* substitution:                          Substitution_and_Command_line_macros.
                                                              (line   6)
* substr:                                substr.              (line   6)
* substring <1>:                         substr.              (line   6)
* substring:                             String_constants_and_string_variables.
                                                              (line  46)
* summation:                             Summation.           (line   6)
* sun:                                   sun.                 (line   6)
* surface <1>:                           surface.             (line   6)
* surface:                               3D_(surface)_plots.  (line   6)
* svg:                                   svg.                 (line   6)
* svga:                                  svga.                (line   6)
* svgalib:                               External_libraries.  (line   6)
* syntax:                                Syntax.              (line   6)
* system <1>:                            system.              (line   6)
* system:                                system_.             (line   6)
* table:                                 table.               (line   6)
* tan:                                   tan.                 (line   6)
* tandy_60dpi:                           epson_180dpi.        (line   6)
* tanh:                                  tanh.                (line   6)
* tc:                                    colorspec.           (line   6)
* tek40:                                 tek40.               (line   6)
* tek410x:                               tek410x.             (line   6)
* term:                                  complete_list_of_terminals.
                                                              (line   6)
* terminal:                              complete_list_of_terminals.
                                                              (line   6)
* termoption:                            termoption.          (line   6)
* ternary:                               Ternary.             (line   6)
* test:                                  test.                (line   6)
* texdraw:                               texdraw.             (line   6)
* text-menu:                             windows.             (line 134)
* textcolor:                             colorspec.           (line   6)
* tgif:                                  tgif.                (line   6)
* thru:                                  thru.                (line   6)
* tics:                                  tics.                (line   6)
* ticscale:                              ticscale.            (line   6)
* ticslevel:                             ticslevel.           (line   6)
* time <1>:                              New_time/date_handling.
                                                              (line   6)
* time:                                  time.                (line   6)
* time/date:                             Time/Date_data.      (line   6)
* time_specifiers:                       time/date_specifiers.
                                                              (line   6)
* timecolumn:                            timecolumn.          (line   6)
* timefmt <1>:                           known_limitations.   (line   9)
* timefmt:                               timefmt.             (line   6)
* timestamp:                             timestamp.           (line   6)
* tips:                                  tips.                (line   6)
* title:                                 title_.              (line   6)
* tkcanvas:                              tkcanvas.            (line   6)
* tm_hour:                               tm_hour.             (line   6)
* tm_mday:                               tm_mday.             (line   6)
* tm_min:                                tm_min.              (line   6)
* tm_mon:                                tm_mon.              (line   6)
* tm_sec:                                tm_sec.              (line   6)
* tm_wday:                               tm_wday.             (line   6)
* tm_yday:                               tm_yday.             (line   6)
* tm_year:                               tm_year.             (line   6)
* tmargin:                               tmargin.             (line   6)
* tpic:                                  tpic.                (line   6)
* trange:                                trange.              (line   6)
* transparency:                          transparency.        (line   6)
* transparent:                           set_style_fill.      (line  44)
* unary:                                 Unary.               (line   6)
* undefine:                              undefine.            (line   6)
* unique:                                smooth.              (line  82)
* unixpc:                                unixpc.              (line   6)
* unset:                                 unset.               (line   6)
* update:                                update.              (line   6)
* urange:                                urange.              (line   6)
* user-defined:                          User-defined_variables_and_functions.
                                                              (line   6)
* using:                                 using.               (line   6)
* UTF-8:                                 encoding.            (line   6)
* valid:                                 valid.               (line   6)
* value:                                 value.               (line   6)
* variables:                             User-defined_variables_and_functions.
                                                              (line   6)
* vectors:                               vectors.             (line   6)
* vgagl:                                 vgagl.               (line   6)
* vgal:                                  emxvga.              (line   6)
* view:                                  view.                (line   6)
* voigt:                                 voigt.               (line   6)
* volatile:                              volatile.            (line   6)
* vrange:                                vrange.              (line   6)
* vttek:                                 tek40.               (line   6)
* VWS:                                   VWS.                 (line   6)
* vx384:                                 vx384.               (line   6)
* wgnuplot.ini:                          windows.             (line 194)
* wgnuplot.mnu:                          windows.             (line 158)
* while:                                 While.               (line   6)
* windows:                               windows.             (line   6)
* with:                                  with.                (line   6)
* word:                                  word.                (line   6)
* words:                                 words.               (line   6)
* writeback:                             xrange.              (line   6)
* wxt <1>:                               cairo_(pdfcairo.     (line   6)
* wxt:                                   wxt.                 (line   6)
* X resources:                           x11.                 (line 217)
* x11:                                   x11.                 (line   6)
* X11:                                   x11.                 (line   6)
* x11_fonts:                             x11.                 (line 102)
* x11_mouse:                             X11_mouse.           (line   6)
* x2data:                                x2data.              (line   6)
* x2dtics:                               x2dtics.             (line   6)
* x2label:                               x2label.             (line   6)
* x2mtics:                               x2mtics.             (line   6)
* x2range:                               x2range.             (line   6)
* x2tics:                                x2tics.              (line   6)
* x2zeroaxis:                            x2zeroaxis.          (line   6)
* xdata:                                 xdata.               (line   6)
* xdtics:                                xdtics.              (line   6)
* xerrorbars:                            xerrorbars.          (line   6)
* xerrorlines:                           xerrorlines.         (line   6)
* xfig:                                  fig.                 (line   6)
* xlabel:                                xlabel.              (line   6)
* xlib:                                  xlib.                (line   6)
* xmtics:                                xmtics.              (line   6)
* xrange:                                xrange.              (line   6)
* xterm:                                 tek40.               (line   6)
* xticlabels:                            using.               (line 148)
* xtics:                                 xtics.               (line   6)
* xyerrorbars:                           xyerrorbars.         (line   6)
* xyerrorlines:                          xyerrorlines.        (line   6)
* xyplane:                               xyplane.             (line   6)
* xzeroaxis:                             xzeroaxis.           (line   6)
* y2data:                                y2data.              (line   6)
* y2dtics:                               y2dtics.             (line   6)
* y2label:                               y2label.             (line   6)
* y2mtics:                               y2mtics.             (line   6)
* y2range:                               y2range.             (line   6)
* y2tics:                                y2tics.              (line   6)
* y2zeroaxis:                            y2zeroaxis.          (line   6)
* ydata:                                 ydata.               (line   6)
* ydtics:                                ydtics.              (line   6)
* yerrorbars:                            yerrorbars.          (line   6)
* yerrorlines:                           yerrorlines.         (line   6)
* ylabel:                                ylabel.              (line   6)
* ymtics:                                ymtics.              (line   6)
* yrange:                                yrange.              (line   6)
* ytics:                                 ytics.               (line   6)
* yzeroaxis:                             yzeroaxis.           (line   6)
* zdata:                                 zdata.               (line   6)
* zdtics:                                zdtics.              (line   6)
* zero:                                  zero.                (line   6)
* zeroaxis:                              zeroaxis.            (line   6)
* zlabel:                                zlabel.              (line   6)
* zmtics:                                zmtics.              (line   6)
* zoom:                                  zoom.                (line   6)
* zrange:                                zrange.              (line   6)
* ztics:                                 ztics.               (line   6)
* zzeroaxis:                             zzeroaxis.           (line   6)


File: gnuplot.info,  Node: Command_Index,  Next: Options_Index,  Prev: Concept_Index,  Up: Top

Command Index
*************

[index]
* Menu:

* call:                                  call.                 (line  6)
* cd:                                    cd.                   (line  6)
* clear:                                 clear.                (line  6)
* evaluate:                              evaluate.             (line  6)
* exit:                                  exit.                 (line  6)
* fit:                                   fit.                  (line  6)
* help:                                  help.                 (line  6)
* history:                               history.              (line  6)
* if:                                    if.                   (line  6)
* iteration <1>:                         iteration.            (line  6)
* iteration <2>:                         iteration_.           (line  6)
* iteration <3>:                         unset.                (line  6)
* iteration:                             set-show.             (line 20)
* load:                                  load.                 (line  6)
* lower:                                 lower.                (line  6)
* pause:                                 pause.                (line  6)
* plot:                                  plot.                 (line  6)
* print:                                 print.                (line  6)
* pwd:                                   pwd.                  (line  6)
* quit:                                  quit.                 (line  6)
* raise:                                 raise.                (line  6)
* refresh:                               refresh.              (line  6)
* replot:                                replot.               (line  6)
* reread:                                reread.               (line  6)
* reset:                                 reset.                (line  6)
* save:                                  save.                 (line  6)
* shell:                                 shell.                (line  6)
* splot:                                 splot.                (line  6)
* system <1>:                            system.               (line  6)
* system:                                system_.              (line  6)
* test:                                  test.                 (line  6)
* undefine:                              undefine.             (line  6)
* unset:                                 unset.                (line  6)
* update:                                update.               (line  6)


File: gnuplot.info,  Node: Options_Index,  Next: Function_Index,  Prev: Command_Index,  Up: Top

Options Index
*************

[index]
* Menu:

* angles:                                angles.               (line  6)
* arrow:                                 arrow.                (line  6)
* autoscale:                             autoscale.            (line  6)
* bars:                                  bars.                 (line  6)
* bind <1>:                              bind_.                (line  6)
* bind <2>:                              bind.                 (line  6)
* bind:                                  reset.                (line 20)
* bmargin:                               bmargin.              (line  6)
* border:                                border.               (line  6)
* boxwidth:                              boxwidth.             (line  6)
* cbdata:                                cbdata.               (line  6)
* cbdtics:                               cbdtics.              (line  6)
* cblabel:                               cblabel.              (line  6)
* cbmtics:                               cbmtics.              (line  6)
* cbrange:                               cbrange.              (line  6)
* cbtics:                                cbtics.               (line  6)
* clabel:                                clabel.               (line  6)
* clip:                                  clip.                 (line  6)
* cntrparam:                             cntrparam.            (line  6)
* colornames:                            colornames.           (line  6)
* contour:                               contour.              (line  6)
* datafile:                              data.                 (line  6)
* decimalsign:                           decimalsign.          (line  6)
* dgrid3d:                               dgrid3d.              (line  6)
* dummy:                                 dummy.                (line  6)
* encoding:                              encoding.             (line  6)
* fontpath:                              fontpath.             (line  6)
* format:                                format_.              (line  6)
* functions:                             functions.            (line  6)
* grid:                                  grid.                 (line  6)
* hidden3d:                              hidden3d.             (line  6)
* historysize:                           historysize.          (line  6)
* isosamples:                            isosamples.           (line  6)
* key:                                   key.                  (line  6)
* label:                                 label.                (line  6)
* linetype:                              linetype.             (line  6)
* lmargin:                               lmargin.              (line  6)
* loadpath:                              loadpath.             (line  6)
* locale <1>:                            decimalsign.          (line  6)
* locale <2>:                            External_libraries.   (line  6)
* locale:                                locale.               (line  6)
* logscale:                              logscale.             (line  6)
* macros:                                Substitution_of_string_variables_as_macros.
                                                               (line  6)
* mapping:                               mapping.              (line  6)
* margin:                                margin.               (line  6)
* mouse:                                 mouse.                (line  6)
* multiplot:                             multiplot.            (line  6)
* mx2tics:                               mx2tics.              (line  6)
* mxtics:                                mxtics.               (line  6)
* my2tics:                               my2tics.              (line  6)
* mytics:                                mytics.               (line  6)
* mztics:                                mztics.               (line  6)
* object:                                object.               (line  6)
* offsets:                               offsets.              (line  6)
* origin:                                origin.               (line  6)
* output:                                output.               (line  6)
* palette:                               palette.              (line  6)
* parametric:                            parametric_.          (line  6)
* pm3d:                                  pm3d.                 (line  6)
* pointintervalbox:                      pointintervalbox.     (line  6)
* pointsize:                             pointsize.            (line  6)
* polar:                                 polar_.               (line  6)
* psdir:                                 psdir.                (line  6)
* raxis:                                 raxis.                (line  6)
* rmargin:                               rmargin.              (line  6)
* rrange:                                rrange.               (line  6)
* rtics:                                 rtics.                (line  6)
* samples:                               samples.              (line  6)
* size:                                  size.                 (line  6)
* style:                                 with.                 (line  6)
* surface <1>:                           3D_(surface)_plots.   (line  6)
* surface:                               surface.              (line  6)
* table:                                 table.                (line  6)
* terminal:                              complete_list_of_terminals.
                                                               (line  6)
* termoption:                            termoption.           (line  6)
* tics:                                  tics.                 (line  6)
* ticscale:                              ticscale.             (line  6)
* ticslevel:                             ticslevel.            (line  6)
* timefmt <1>:                           timefmt.              (line  6)
* timefmt:                               known_limitations.    (line  9)
* timestamp:                             timestamp.            (line  6)
* title:                                 title_.               (line  6)
* tmargin:                               tmargin.              (line  6)
* trange:                                trange.               (line  6)
* urange:                                urange.               (line  6)
* variables:                             User-defined_variables_and_functions.
                                                               (line  6)
* view:                                  view.                 (line  6)
* vrange:                                vrange.               (line  6)
* x2data:                                x2data.               (line  6)
* x2dtics:                               x2dtics.              (line  6)
* x2label:                               x2label.              (line  6)
* x2mtics:                               x2mtics.              (line  6)
* x2range:                               x2range.              (line  6)
* x2tics:                                x2tics.               (line  6)
* x2zeroaxis:                            x2zeroaxis.           (line  6)
* xdata:                                 xdata.                (line  6)
* xdtics:                                xdtics.               (line  6)
* xlabel:                                xlabel.               (line  6)
* xmtics:                                xmtics.               (line  6)
* xrange:                                xrange.               (line  6)
* xtics:                                 xtics.                (line  6)
* xyplane:                               xyplane.              (line  6)
* xzeroaxis:                             xzeroaxis.            (line  6)
* y2data:                                y2data.               (line  6)
* y2dtics:                               y2dtics.              (line  6)
* y2label:                               y2label.              (line  6)
* y2mtics:                               y2mtics.              (line  6)
* y2range:                               y2range.              (line  6)
* y2tics:                                y2tics.               (line  6)
* y2zeroaxis:                            y2zeroaxis.           (line  6)
* ydata:                                 ydata.                (line  6)
* ydtics:                                ydtics.               (line  6)
* ylabel:                                ylabel.               (line  6)
* ymtics:                                ymtics.               (line  6)
* yrange:                                yrange.               (line  6)
* ytics:                                 ytics.                (line  6)
* yzeroaxis:                             yzeroaxis.            (line  6)
* zdata:                                 zdata.                (line  6)
* zdtics:                                zdtics.               (line  6)
* zero:                                  zero.                 (line  6)
* zeroaxis:                              zeroaxis.             (line  6)
* zlabel:                                zlabel.               (line  6)
* zmtics:                                zmtics.               (line  6)
* zrange:                                zrange.               (line  6)
* ztics:                                 ztics.                (line  6)
* zzeroaxis:                             zzeroaxis.            (line  6)


File: gnuplot.info,  Node: Function_Index,  Next: Terminal_Index,  Prev: Options_Index,  Up: Top

Function Index
**************

[index]
* Menu:

* abs:                                   abs.                  (line  6)
* acos:                                  acos.                 (line  6)
* acosh:                                 acosh.                (line  6)
* airy:                                  airy.                 (line  6)
* arg:                                   arg.                  (line  6)
* asin:                                  asin.                 (line  6)
* asinh:                                 asinh.                (line  6)
* atan:                                  atan.                 (line  6)
* atan2:                                 atan2.                (line  6)
* atanh:                                 atanh.                (line  6)
* besj0:                                 besj0.                (line  6)
* besj1:                                 besj1.                (line  6)
* besy0:                                 besy0.                (line  6)
* besy1:                                 besy1.                (line  6)
* ceil:                                  ceil.                 (line  6)
* column <1>:                            using.                (line 27)
* column:                                column.               (line  6)
* columnhead <1>:                        columnhead.           (line  6)
* columnhead:                            using.                (line 29)
* cos:                                   cos.                  (line  6)
* cosh:                                  cosh.                 (line  6)
* defined:                               defined.              (line  6)
* elliptic integrals:                    elliptic_integrals.   (line  6)
* erf:                                   erf.                  (line  6)
* erfc:                                  erfc.                 (line  6)
* exists <1>:                            Substitution_of_string_variables_as_macros.
                                                               (line  6)
* exists:                                exists.               (line  6)
* exp:                                   exp.                  (line  6)
* expint:                                expint.               (line  6)
* floor:                                 floor.                (line  6)
* gamma <1>:                             known_limitations.    (line  9)
* gamma:                                 gamma.                (line  6)
* gprintf:                               gprintf_.             (line  6)
* ibeta:                                 ibeta.                (line  6)
* igamma:                                igamma.               (line  6)
* imag:                                  imag.                 (line  6)
* int:                                   int.                  (line  6)
* inverf:                                inverf.               (line  6)
* invnorm:                               invnorm.              (line  6)
* lambertw:                              lambertw.             (line  6)
* lgamma:                                lgamma.               (line  6)
* log:                                   log.                  (line  6)
* log10:                                 log10.                (line  6)
* norm:                                  norm.                 (line  6)
* rand <1>:                              Random_number_generator.
                                                               (line  6)
* rand:                                  rand.                 (line  6)
* real:                                  real.                 (line  6)
* sgn:                                   sgn.                  (line  6)
* sin:                                   sin.                  (line  6)
* sinh:                                  sinh.                 (line  6)
* sprintf:                               sprintf.              (line  6)
* sqrt:                                  sqrt.                 (line  6)
* strftime:                              strftime.             (line  6)
* stringcolumn:                          stringcolumn.         (line  6)
* strlen:                                strlen.               (line  6)
* strptime:                              strptime.             (line  6)
* strstrt:                               strstrt.              (line  6)
* substr:                                substr.               (line  6)
* tan:                                   tan.                  (line  6)
* tanh:                                  tanh.                 (line  6)
* time <1>:                              New_time/date_handling.
                                                               (line  6)
* time:                                  time.                 (line  6)
* timecolumn:                            timecolumn.           (line  6)
* tm_hour:                               tm_hour.              (line  6)
* tm_mday:                               tm_mday.              (line  6)
* tm_min:                                tm_min.               (line  6)
* tm_mon:                                tm_mon.               (line  6)
* tm_sec:                                tm_sec.               (line  6)
* tm_wday:                               tm_wday.              (line  6)
* tm_yday:                               tm_yday.              (line  6)
* tm_year:                               tm_year.              (line  6)
* valid:                                 valid.                (line  6)
* value:                                 value.                (line  6)
* voigt:                                 voigt.                (line  6)
* word:                                  word.                 (line  6)
* words:                                 words.                (line  6)


File: gnuplot.info,  Node: Terminal_Index,  Prev: Function_Index,  Up: Top

Terminal Index
**************

[index]
* Menu:

* aed512:                                aed767.              (line   6)
* aed767:                                aed767.              (line   6)
* cgi:                                   cgi.                 (line   6)
* cgm:                                   cgm.                 (line   6)
* context:                               context.             (line   6)
* corel:                                 corel.               (line   6)
* debug:                                 debug.               (line   6)
* dospc:                                 dospc.               (line   6)
* dpu414:                                epson_180dpi.        (line   6)
* dumb:                                  dumb.                (line   6)
* dxf:                                   dxf.                 (line   6)
* dxy800a:                               dxy800a.             (line   6)
* eepic:                                 eepic.               (line   6)
* emf:                                   emf.                 (line   6)
* emtex:                                 latex.               (line   6)
* emxvesa:                               emxvga.              (line   6)
* emxvga:                                emxvga.              (line   6)
* epscairo:                              epscairo.            (line   6)
* excl:                                  excl.                (line   6)
* ggi:                                   ggi.                 (line   6)
* gpic:                                  gpic.                (line   6)
* graph-menu:                            windows.             (line  68)
* grass:                                 grass.               (line   6)
* hcgi:                                  cgi.                 (line   6)
* hp2623a:                               hp2623a.             (line   6)
* hp2648:                                hp2648.              (line   6)
* hp500c:                                hp500c.              (line   6)
* hpdj:                                  hpljii.              (line   6)
* hpgl:                                  hpgl.                (line   6)
* hpljii:                                hpljii.              (line   6)
* hppj:                                  hppj.                (line   6)
* imagen:                                imagen.              (line   6)
* kc-tek40xx:                            tek40.               (line   6)
* kyo:                                   kyo.                 (line   6)
* latex:                                 latex.               (line   6)
* linux:                                 linux.               (line   6)
* lua:                                   lua.                 (line   6)
* macintosh:                             macintosh.           (line   6)
* mif:                                   mif.                 (line   6)
* okidata:                               epson_180dpi.        (line   6)
* pbm:                                   pbm.                 (line   6)
* pcl5:                                  hpgl.                (line   6)
* pdf <1>:                               cairo_(pdfcairo.     (line   6)
* pdf <2>:                               External_libraries.  (line   6)
* pdf:                                   pdf.                 (line   6)
* png <1>:                               gd_(png.             (line   6)
* png <2>:                               cairo_(pdfcairo.     (line   6)
* png:                                   png_.                (line   6)
* prescribe:                             kyo.                 (line   6)
* pstricks:                              pstricks.            (line   6)
* qms:                                   qms.                 (line   6)
* regis:                                 regis.               (line   6)
* starc:                                 epson_180dpi.        (line   6)
* sun:                                   sun.                 (line   6)
* svg:                                   svg.                 (line   6)
* svga:                                  svga.                (line   6)
* tek40:                                 tek40.               (line   6)
* tek410x:                               tek410x.             (line   6)
* texdraw:                               texdraw.             (line   6)
* text-menu:                             windows.             (line 134)
* tgif:                                  tgif.                (line   6)
* tkcanvas:                              tkcanvas.            (line   6)
* tpic:                                  tpic.                (line   6)
* unixpc:                                unixpc.              (line   6)
* vgagl:                                 vgagl.               (line   6)
* vgal:                                  emxvga.              (line   6)
* vttek:                                 tek40.               (line   6)
* VWS:                                   VWS.                 (line   6)
* vx384:                                 vx384.               (line   6)
* wgnuplot.ini:                          windows.             (line 194)
* wgnuplot.mnu:                          windows.             (line 158)
* windows:                               windows.             (line   6)
* wxt <1>:                               cairo_(pdfcairo.     (line   6)
* wxt:                                   wxt.                 (line   6)
* xlib:                                  xlib.                (line   6)
* xterm:                                 tek40.               (line   6)



Tag Table:
Node: Top207
Node: gnuplot1180
Node: Copyright1776
Node: Introduction3743
Node: Seeking-assistance8381
Node: New_features9994
Node: New_syntax10477
Node: Local_customization_of_linetypes11635
Node: New_plot_styles12281
Node: Revised_polar_axes12569
Node: New_smoothing_algorithms12928
Node: New_time/date_handling13458
Node: Statistical_summary_of_data13996
Node: New_or_revised_terminal_drivers14631
Node: Backwards_compatibility17505
Node: Batch/Interactive_Operation18588
Node: Canvas_size20249
Node: Command-line-editing21892
Node: Comments23202
Node: Coordinates23821
Node: Datastrings25913
Node: Enhanced_text_mode27810
Node: Environment31932
Node: Expressions34810
Node: Functions37513
Node: abs38837
Node: acos39195
Node: acosh39465
Node: airy39665
Node: arg40009
Node: asin40227
Node: asinh40491
Node: atan40688
Node: atan240962
Node: atanh41305
Node: EllipticK41514
Node: EllipticE41670
Node: EllipticPi41831
Node: besj041990
Node: besj142237
Node: besy042479
Node: besy142721
Node: ceil42962
Node: cos43268
Node: cosh43514
Node: erf43743
Node: erfc44058
Node: exp44374
Node: expint44776
Node: floor45097
Node: gamma45407
Node: ibeta45712
Node: inverf46189
Node: igamma46434
Node: imag46876
Node: invnorm47074
Node: int47341
Node: lambertw47541
Node: lgamma47849
Node: log48151
Node: log1048360
Node: norm48544
Node: rand48821
Node: real49026
Node: sgn49196
Node: sin49495
Node: sinh49744
Node: sqrt49972
Node: tan50144
Node: tanh50397
Node: voigt50629
Node: gprintf50904
Node: sprintf51268
Node: strlen51736
Node: strstrt52039
Node: substr52467
Node: strftime52829
Node: strptime53114
Node: system53427
Node: word53857
Node: words54085
Node: column54300
Node: columnhead54617
Node: defined54971
Node: exists55197
Node: stringcolumn55505
Node: timecolumn55840
Node: tm_hour56607
Node: tm_mday56889
Node: tm_min57179
Node: tm_mon57455
Node: tm_sec57729
Node: tm_wday58005
Node: tm_yday58293
Node: tm_year58584
Node: time58842
Node: valid59551
Node: elliptic_integrals59806
Node: Random_number_generator60797
Node: value61696
Node: Operators62284
Node: Unary62776
Node: Binary63683
Node: Ternary65575
Node: Summation67085
Node: Gnuplot-defined_variables68076
Node: User-defined_variables_and_functions70096
Node: Fonts72348
Node: cairo_(pdfcairo72909
Node: gd_(png73644
Node: postscript__(also_encapsulated_postscript_*.eps)75423
Node: Glossary77255
Node: linetypes79751
Node: colorspec82782
Node: background_color85024
Node: linecolor_variable85699
Node: rgbcolor_variable86777
Node: linestyles_vs_linetypes87861
Node: mouse_input88835
Node: bind89518
Node: bind_space92718
Node: Mouse_variables93127
Node: Plotting94799
Node: Start-up_(initialization)96933
Node: String_constants_and_string_variables97763
Node: Substitution_and_Command_line_macros99999
Node: Substitution_of_system_commands_in_backquotes100611
Node: Substitution_of_string_variables_as_macros101733
Node: String_variables103878
Node: Syntax105410
Node: Quote_Marks107736
Node: Time/Date_data109512
Node: plotting_styles112747
Node: boxerrorbars114195
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