/* D01FB_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 <iostream>
using namespace std;

extern "C"
{
  static void NAG_CALL fun(void* &ad_handle,
                           const Integer& ndim,
                           const double x[],
                           double& ret,
                           Integer iuser[],
                           double ruser[]);
}

int main(void)
{
  // Scalars
  int     exit_status = 0;
  Integer ndim = 4;

  cout << "D01FB_P0W_F C++ Header Example Program Results\n\n";

  // Allocate memory
  Integer *nptvec = 0;
  double  *abscis = 0, *weight = 0;
  Integer lwa = 0;

  nptvec = new Integer [ndim];
  for (int i=0;i<ndim;i++) {
    nptvec[i] = 4;
    lwa = lwa + nptvec[i];
  }
  abscis = new double [lwa];
  weight = new double [lwa];

  void    *ad_handle = 0;
  // Evaluate primal weights and abscisae in each dimension
  int j = 0;
  for (int i=0;i<ndim;i++) {

    Integer ifail = 0, quadtype = 0;
    double a, b;
    switch (i) {
    case 0:
      a = 1.0;
      b = 2.0;
      quadtype = 0;
      break;
    case 1:
      a = 0.0;
      b = 2.0;
      quadtype = -3;
      break;
    case 2:
      a = 0.0;
      b = 0.5;
      quadtype = -4;
      break;
    case 3:
      a = 1.0;
      b = 2.0;
      quadtype = -5;
      break;
    }
    d01tb_p0w_f_(ad_handle,quadtype,a,b,nptvec[i],&weight[j],&abscis[j],
                 ifail);
    j = j + nptvec[i];
  }

  // Call the passive routine
  Integer ifail = 0;
  double  ans;
  double  ruser[1];
  Integer iuser[1];
  d01fb_p0w_f_(ad_handle,ndim,nptvec,lwa,weight,abscis,
               fun,ans,iuser,ruser,ifail);

  cout.setf(ios::right);
  cout.precision(4);
  cout << "\n Solution, x = ";
  cout.width(12); cout << ans << endl;

  delete [] nptvec;
  delete [] abscis;
  delete [] weight;
  return exit_status;
}
static void NAG_CALL fun(void* &ad_handle,
                             const Integer& ndim,
                             const double x[],
                             double& ret,
                             Integer iuser[],
                             double ruser[])
{
  double    p1 = 6.0, p2 = 8.0;
  ret = (pow(x[0]*x[1]*x[2],p1)/pow(x[3]+2.0,p2))*
    exp(-2.0*x[1]-0.5*x[2]*x[2]);
  return;
}