// $Id: vec_ad_par.cpp 3785 2016-02-08 12:53:06Z bradbell $
/* --------------------------------------------------------------------------
CppAD: C++ Algorithmic Differentiation: Copyright (C) 2003-15 Bradley M. Bell

CppAD is distributed under multiple licenses. This distribution is under
the terms of the
                    GNU General Public License Version 3.

A copy of this license is included in the COPYING file of this distribution.
Please visit http://www.coin-or.org/CppAD/ for information on other licenses.
-------------------------------------------------------------------------- */

/*
Test the use of the parameters in VecAD element assignments
*/

# include <cppad/cppad.hpp>

typedef CppAD::AD<double>      ADdouble;
typedef CppAD::AD< ADdouble > ADDdouble;

bool VecADPar(void)
{
	using namespace CppAD;

	bool ok = true;

	CPPAD_TESTVECTOR( ADdouble ) x(2);
	x[0] = 0;
	x[1] = 0;
	Independent(x);

	CPPAD_TESTVECTOR( ADDdouble ) y(1);
	y[0] = 1;
	Independent(y);

	VecAD< ADdouble > v(2);
	ADDdouble zero(0);
	ADDdouble one(1);
	v[zero] = x[0]; // these two parameter values are equal,
	v[one]  = x[1]; // but they are not identically equal

	CPPAD_TESTVECTOR( ADDdouble ) z(1);
	z[0] = v[zero] + v[one];

	// f(y) = x[0] + x[1]
	ADFun< ADdouble > f(y, z);
	CPPAD_TESTVECTOR( ADdouble ) a( f.Domain() );
	CPPAD_TESTVECTOR( ADdouble ) b( f.Range() );

	// fy = f(y) = x[0] + x[1]
	a[0]  = 0.;
	b     = f.Forward(0, a);

	// check value of f
	ok &= b[0] == (x[0] + x[1]);

	// g(x) = x[0] + x[1];
	ADFun<double> g(x, b);
	CPPAD_TESTVECTOR( double ) c( g.Domain() );
	CPPAD_TESTVECTOR( double ) d( g.Range() );

	// d = g(1, 2)
	c[0] = 1.;   // these tow values are not equal and correspond
	c[1] = 2.;   // to replacements for the equal parameter values above
	d = g.Forward(0, c);

	// check function value
	ok &= (d[0] == c[0] + c[1]);

	return ok;
}
