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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
// ----------------------------------------------------------------------------
/*
Old example now just used for validation testing.
*/
# include <cppad/cppad.hpp>
bool PowInt(void)
{ bool ok = true;
using CppAD::pow;
using CppAD::exp;
using CppAD::log;
using namespace CppAD;
double eps99 = 99.0 * std::numeric_limits<double>::epsilon();
// independent variable vector, indices, values, and declaration
CPPAD_TESTVECTOR(AD<double>) U(1);
U[0] = 2.;
Independent(U);
// dependent variable vector and indices
CPPAD_TESTVECTOR(AD<double>) Z(2);
// dependent variable values
Z[0] = pow(U[0], 5); // x = u^5
Z[1] = pow(U[0], -5); // y = u^{-5}
// create f: U -> Z and vectors used for derivative calculations
ADFun<double> f(U, Z);
CPPAD_TESTVECTOR(double) v( f.Domain() );
CPPAD_TESTVECTOR(double) w( f.Range() );
/*
x_u = 5 * u^4
y_u = - 5 * u^{-6}
*/
// check function values values
double u = Value(U[0]);
ok &= NearEqual(Z[0] , exp( log(u) * 5.), eps99 , eps99);
ok &= NearEqual(Z[1] , exp( - log(u) * 5.), eps99 , eps99);
// forward computation of partials
v[0] = 1.;
w = f.Forward(1, v);
ok &= NearEqual(w[0] , 5. * exp( log(u) * 4.), eps99 , eps99);
ok &= NearEqual(w[1] , - 5. * exp( - log(u) * 6.), eps99 , eps99);
return ok;
}
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