NAG Library Manual, Mark 29
Interfaces:  FL   CL   CPP   AD 

NAG AD Library Introduction
Example description
/* S01BA_T1W_F C++ Header Example Program.
 *
 * Copyright 2023 Numerical Algorithms Group.
 * Mark 29.0, 2023.
 */

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

int main()
{
  int exit_status = 0;

  // Input and output variables
  nagad_t1w_w_rtype x, y;

  cout << "S01BA_T1W_F C++ Header Example Program Results\n\n";
  // Skip heading in data file
  string mystr;
  getline(cin, mystr);

  // Read number of x values
  Integer n;
  cin >> n;

  // Create AD configuration data object
  Integer           ifail = 0;
  nag::ad::handle_t ad_handle;

  cout << "       x       y=ln(1+x)     dy/dx\n";
  cout.setf(ios::scientific, ios::floatfield);
  cout.setf(ios::right);
  cout.precision(4);

  // Loop over x values
  for (Integer i = 0; i < n; ++i)
  {
    // Read next x
    double xr;
    cin >> xr;

    x                  = xr;
    double inc         = 1.0;
    dco::derivative(x) = inc;

    // Call NAG AD Routine
    ifail = -1;
    nag::ad::s01ba(ad_handle, x, y, ifail);
    if (ifail != 0)
    {
      exit_status = 2;
      goto END;
    }

    double dydx;
    dydx = dco::derivative(y);

    cout.width(12);
    cout << dco::value(x);
    cout.width(12);
    cout << dco::value(y);
    cout.width(12);
    cout << dydx << endl;
  }

END:

  return exit_status;
}