#include "dco.hpp"
/* X10AA_A1W_F C++ Header Example Program.
*
* Copyright 2024 Numerical Algorithms Group.
* Mark 30.1, 2024.
*/
#include <iostream>
#include <nag.h>
#include <nagad.h>
#include <stdio.h>
using namespace std;
int main()
{
/* Scalars */
Integer exit_status = 0, ierr_not_implemented = -199;
nagad_a1w_w_rtype x, y;
Integer ifail, mode;
double dydx, dydx_exp, y1, inc;
/* Arrays */
nag::ad::handle_t handle;
cout << "X10AA_A1W_F C++ Header Example Program Results\n\n";
/* Create AD tape */
dco::ga1s<double>::global_tape = dco::ga1s<double>::tape_t::create();
x = 0.1;
cout << "Computing ln(1+x) and its adjoint using s01ba\n\n";
/* Create AD configuration data object */
ifail = 0;
nag::ad::x10aa(handle.data(), ifail);
/* Set computational mode to nagad_symbolic */
mode = nagad_symbolic;
ifail = 0;
nag::ad::x10ac(handle.data(), mode, ifail);
/* Get and print computational mode */
/* Register variables to differentiate w.r.t. */
ifail = 0;
nag::ad::x10ad(handle.data(), mode, ifail);
if (mode == nagad_symbolic)
{
cout << "Symbolic computational mode is being used\n\n";
}
else if (mode == nagad_algorithmic)
{
cout << "Algorithmic computational mode is being used\n\n";
}
/* Try AD computation that expects to use only the algorithmic mode */
ifail = 1;
nag::ad::s01ba(handle, x, y, ifail);
if (ifail == ierr_not_implemented)
{
cout << "AD computation failed as expected with ifail = " << ifail
<< "\n\n";
}
else
{
cout << " Unexpected IFAIL returned in AD computation\n";
cout << " ifail expected: " << ierr_not_implemented << ifail << "\n";
cout << " ifail returned: " << ifail << "\n";
exit_status = 1;
goto END;
}
/* Reset computational mode to nagad_algorithmic */
mode = nagad_algorithmic;
ifail = 0;
nag::ad::x10ac(handle.data(), mode, ifail);
ifail = 0;
nag::ad::x10ad(handle.data(), mode, ifail);
if (mode == nagad_symbolic)
{
cout << "Symbolic computational mode is being used\n\n";
}
else if (mode == nagad_algorithmic)
{
cout << "Algorithmic computational mode is being used\n\n";
}
dco::ga1s<double>::global_tape->register_variable(x);
ifail = 0;
nag::ad::s01ba(handle, x, y, ifail);
y1 = dco::value(y);
inc = 1.0;
dco::derivative(y) += inc;
ifail = 0;
dco::ga1s<double>::global_tape->sparse_interpret() = true;
dco::ga1s<double>::global_tape->interpret_adjoint();
/* Get derivatives */
dydx = dco::derivative(x);
dydx_exp = 1.0 / (1.0 + dco::value(x));
cout.setf(ios::scientific, ios::floatfield);
cout.precision(4);
cout << "Input value of x : " << dco::value(x) << endl;
cout << "Output value of ln(1+x) : " << y1 << endl;
cout << "AD evaluated derivative : " << dydx << endl;
cout << "Directly computed derivative : " << dydx_exp << endl;
/* Remove computational data object and tape */
END:
ifail = 0;
nag::ad::x10ab(handle.data(), ifail);
dco::ga1s<double>::tape_t::remove(dco::ga1s<double>::global_tape);
return exit_status;
}