/* D01GA_T1W_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 <math.h>
#include <iostream>
using namespace std;

int main(void)
{
  // Scalars
  int               exit_status = 0;
  Integer           n = 21;
  double            ar = 1.0;

  cout << "D01GA_T1W_F C++ Header Example Program Results\n\n";

  // Allocate memory
  nagad_t1w_w_rtype *x = 0, *y = 0;

  x = new nagad_t1w_w_rtype [n];
  y = new nagad_t1w_w_rtype [n];

  // Create AD configuration data object
  Integer ifail = 0;
  void    *ad_handle = 0;
  x10aa_t1w_f_(ad_handle,ifail);

  nagad_t1w_w_rtype a;
  a = ar;

  double inc = 1.0;
  nagad_t1w_inc_derivative(&a,inc);

  // Initialize variables
  for (int i = 0; i < n; i++) {
    double xr = (1.0*i)/(1.0*(n-1));
    nagad_t1w_w_rtype tmp;
    x[i] = xr;
    tmp = a*x[i];
    y[i] = 4.0/(1.0 + tmp*tmp);
  }

  // Call the AD routine
  ifail = 0;
  nagad_t1w_w_rtype ans, er;
  
  d01ga_t1w_f_(ad_handle,x,y,n,ans,er,ifail);
  
  double da;
  da = nagad_t1w_get_derivative(ans);

  cout << "\n Derivatives calculated: First order tangents\n";
  cout << " Computational mode    : algorithmic\n";

  cout.setf(ios::scientific,ios::floatfield);
  cout.setf(ios::right);
  cout.precision(4);
  cout << "\n Solution, ans = ";
  double ans_value = nagad_t1w_get_value(ans);
  cout.width(12); cout << ans_value << endl;
  cout << "\n Derivative:\n";
  cout <<  " d(ans)/da = ";
  cout.width(12); cout << da << endl;

  // Remove computational data object
  x10ab_t1w_f_(ad_handle,ifail);

  delete [] x;
  delete [] y;
  return exit_status;
}