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// SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-or-later
// SPDX-FileCopyrightText: Bradley M. Bell <bradbell@seanet.com>
// SPDX-FileContributor: 2003-22 Bradley M. Bell
// ----------------------------------------------------------------------------
/*
{xrst_begin number_skip.cpp}
Number of Variables That Can be Skipped: Example and Test
#########################################################
{xrst_literal
// BEGIN C++
// END C++
}
{xrst_end number_skip.cpp}
*/
// BEGIN C++
# include <cppad/cppad.hpp>
bool number_skip(void)
{ bool ok = true;
using CppAD::AD;
// independent variable vector
CppAD::vector< AD<double> > ax(2);
ax[0] = 0.;
ax[1] = 1.;
Independent(ax);
// Use a conditional expression
CppAD::vector< AD<double> > ay(1);
// variable that gets optimized out
AD<double> az = ax[0] * ax[0];
// conditional expression
ay[0] = CondExpLt(ax[0], ax[1], ax[0] + ax[1], ax[0] - ax[1]);
// create function object F : x -> ay
CppAD::ADFun<double> f;
f.Dependent(ax, ay);
// use zero order to evaluate F[ (3, 4) ]
CppAD::vector<double> x( f.Domain() );
CppAD::vector<double> y( f.Range() );
x[0] = 3.;
x[1] = 4.;
y = f.Forward(0, x);
ok &= (y[0] == x[0] + x[1]);
// before call to optimize
ok &= f.number_skip() == 0;
size_t n_var = f.size_var();
// now optimize the operation sequence
f.optimize();
// after optimize, check forward mode result
x[0] = 4.;
x[1] = 3.;
y = f.Forward(0, x);
ok &= (y[0] == x[0] - x[1]);
// after optimize, check amount of optimization
ok &= f.size_var() == n_var - 1;
ok &= f.number_skip() == 1;
return ok;
}
// END C++
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