NAG Library Manual, Mark 28.3
Interfaces:  FL   CL   CPP   AD 

NAG AD Library Introduction
Example description
/* G01EA_T1W_F C++ Header Example Program.
 *
 * Copyright 2022 Numerical Algorithms Group.
 * Mark 28.3, 2022.
 */

#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, p;

  cout << "G01EA_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 << "Two tail significance levels and derivatives\n\n";
  cout << "       x           p         dp/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 = 0;
    nag::ad::g01ea(ad_handle, "S", x, p, ifail);

    double dpdx;
    dpdx = dco::derivative(p);

    cout.width(12);
    cout << dco::value(x);
    cout.width(12);
    cout << dco::value(p);
    cout.width(12);
    cout << dpdx << endl;
  }

END:

  return exit_status;
}