/* S15AD_A1W_F C++ Header Example Program.
 *
 * Copyright 2019 Numerical Algorithms Group.
 * Mark 27, 2019.
 */

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

int main(void)
{
  int exit_status = 0;

  // Input and output variables
  nagad_a1w_w_rtype e, x;

  cout << "S15AD_A1W_F C++ Header Example Program Results\n\n";

  // Create AD tape
  nagad_a1w_ir_create();

  x = -1.;

  // Create AD configuration data object
  Integer ifail = 0;
  void    *ad_handle = 0;
  x10aa_a1w_f_(ad_handle,ifail);

  cout << "       x         erfc(x)   derfc/dx\n";
  cout.setf(ios::scientific,ios::floatfield);
  cout.setf(ios::right);
  cout.precision(4);

  // Register x, i.e. differentiate w.r.t. x
  nagad_a1w_ir_register_variable(&x);

  // Call NAG AD Routine
  ifail = 0;
  s15ad_a1w_f_(ad_handle,x,e,ifail);

  // Reset adjoints, increment e, and evaluate adjoint of erfc w.r.t. x
  nagad_a1w_ir_zero_adjoints();
  double inc = 1.0;
  nagad_a1w_inc_derivative(&e,inc);
  ifail = 0;
  nagad_a1w_ir_interpret_adjoint(ifail);

  // Get derivative, derfcdx and output values
  double dedx;
  dedx = nagad_a1w_get_derivative(x);

  cout.width(12);  cout << nagad_a1w_get_value(x);
  cout.width(12);  cout << nagad_a1w_get_value(e);
  cout.width(12);  cout << dedx << endl;

  // Remove computational data object and tape
  x10ab_a1w_f_(ad_handle,ifail);
  nagad_a1w_ir_remove();

  return exit_status;
}