Notes on creating new map databases.

1) See the references:
Richard A. Becker, and Allan R. Wilks,
"Maps in S",
emph{AT\&T Bell Laboratories Statistics Research Report [93.2], 1993.}

Richard A. Becker, and Allan R. Wilks,
"Constructing a Geographical Database",
\emph{AT\&T Bell Laboratories Statistics Research Report [95.2], 1995.}

2) After the .line .gon and .n ascii files have been created or modified,
rerun ./getstats.sh to generate the appropriate .linestats and .gonstats
files.

3) Edit the Makefiles to add the appropriate names to the lists of
.G, .L and .N files

4) Create the ../data/<mapname>.r file consisting of the assignment
'<mapname>MapEnv <- "R_MAPDATA_DATA_DIR"'.  This is the name of
the environment variable, created at load time (see ../R/zzz.R),
that specifies the location of the binary data files for this
collection of maps. [The maps package uses a different environment
variable.  If you wish to create another package similar to this
one for your own map databases, then choose yet a different
environment variable.]

Ray Brownrigg
21 March 2009
