NAG Library Manual, Mark 27.2
Interfaces:  FL   CL   CPP   AD 

NAG AD Library Introduction
Example description
/* S18DE_T1W_F C++ Header Example Program.
 *
 * Copyright 2021 Numerical Algorithms Group.
 * Mark 27.2, 2021.
 */

#include <dco.hpp>
#include <iostream>
#include <nag.h>
#include <nagad.h>
#include <stdio.h>
#include <string>
using namespace std;

int main(void)
{
  int exit_status = 0;

  // Input and output variables

  cout << "S18DE_T1W_F C++ Header Example Program Results\n\n";

  // Create AD configuration data object
  Integer ifail     = 0;
  void *  ad_handle = 0;
  nag::ad::x10aa(ad_handle, ifail);

  cout << "    nu               z             scal";
  cout << "         cy[0]                      dy/dnu\n";
  cout.setf(ios::scientific, ios::floatfield);
  cout.setf(ios::right);
  cout.precision(2);

  const Integer     n = 1;
  nagad_t1w_w_rtype fnu, x, zr, zi;
  nagad_t1w_w_ctype z, cy[n];
  Integer           nz;
  fnu = 5.5;
  zr  = -6.1;
  zi  = 9.8;
  z.real(zr);
  z.imag(zi);

  // Call NAG AD Routine
  double inc           = 1.0;
  dco::derivative(fnu) = inc;
  ifail                = 0;
  nag::ad::s18de(ad_handle, fnu, z, n, "S", cy, nz, ifail);

  nagad_t1w_w_rtype cyr;
  cyr           = real(cy[0]);
  double dyrdnu = dco::derivative(cyr);

  nagad_t1w_w_rtype cyi;
  cyi           = imag(cy[0]);
  double dyidnu = dco::derivative(cyi);

  cout.width(10);
  cout << dco::value(fnu) << " (";
  cout.width(9);
  cout << dco::value(real(z)) << ",";
  cout.width(10);
  cout << dco::value(imag(z)) << ")   S   (";
  cout.width(9);
  cout << dco::value(cyr) << ",";
  cout.width(10);
  cout << dco::value(cyi) << ")    (";
  cout.width(9);
  cout << dyrdnu << ",";
  cout.width(10);
  cout << dyidnu << ")" << endl;

  // Remove computational data object and tape
  nag::ad::x10ab(ad_handle, ifail);

  return exit_status;
}