/* E01BG_P0W_F C++ Header Example Program.
 *
 * Copyright 2019 Numerical Algorithms Group.
 * Mark 27, 2019.
 */

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

int main(void)
{
  // Scalars
  int exit_status = 0;
  
  cout << "E01BG_P0W_F C++ Header Example Program Results\n\n";

  // Skip first line of data file
  string mystr;
  getline (cin, mystr);
  // Read number of data points
  Integer n;
  cin >> n;

  // Allocate arrays for data and interpolant
  double *x = 0, *f = 0, *d = 0;
  x = new double [n];
  f = new double [n];
  d = new double [n];

  // Read data variables
  for (int i=0; i<n; i++) {
    cin >> x[i] >> f[i];
  }
    
  // Call the passive routine
  Integer ifail = 0;
  void    *ad_handle = 0;
  e01be_p0w_f_(ad_handle,n,x,f,d,ifail);

  const Integer m = 1;
  double        px[m], pf[m], pd[m];
  px[0] = 0.5*(x[n/2-1] + x[n/2]);
  ifail = 0;
  e01bg_p0w_f_(ad_handle,n,x,f,d,m,px,pf,pd,ifail);

  cout << "\n Value of interpolant at x = " << px[0];
  cout.precision(5);
  cout << " is: " << pf[0] << endl;

  delete [] x;
  delete [] f;
  delete [] d;
  return exit_status;
}