/* D01UA_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 f(void* &ad_handle,
                             const double x[],
                             const Integer& nx,
                             double fv[],
                             Integer& iflag,
                             Integer iuser[],
                             double ruser[]);
}

int main(void)
{
  // Scalars
  int     exit_status = 0;
  Integer n = 64;
  // Arrays
  double  ruser[1];
  Integer iuser[1];

  ruser[0] = 1.0;

  cout << "D01UA_P0W_F C++ Header Example Program Results\n\n";

  Integer ifail = 0;
  void    *ad_handle = 0;

  double  a, b;
  Integer key;
  for (int funid = 1; funid <= 6; funid++) {
    if (funid==1) {
      a = 0.0;
      b = 1.0;
      key = 0;
    }
    if (funid==2) {
      a = 2.0;
      b = 0.0;
      key = -5;
    }
    if (funid==3) {
      a = 2.0;
      b = 1.0;
      key = -3;
    }
    if (funid==4) {
      a = 2.0;
      b = 1.0;
      key = 3;
    }
    if (funid==5) {
      a = -1.0;
      b = 3.0;
      key = -4;
    }
    if (funid==6) {
      a = -1.0;
      b = 3.0;
      key = 4;
    }

    iuser[0] = funid;

    // Call the passive routine
    ifail = 0;
    double dinest;
    d01ua_p0w_f_(ad_handle,key,a,b,n,f,dinest,iuser,ruser,ifail);

    cout.setf(ios::scientific,ios::floatfield);
    cout.setf(ios::right);
    cout.precision(4);
    cout << "\n dinest = ";
    cout.width(12); cout << dinest << "     ";
  }

  return exit_status;
}

static void NAG_CALL f(void* &ad_handle,
                           const double x[],
                           const Integer& nx,
                           double fv[],
                           Integer& iflag,
                           Integer iuser[],
                           double ruser[])
{
  Integer i;
  double xx, fx, rux;
  for (i=0; i<nx && iflag>=0; i++) {
    xx = x[i];
    rux = ruser[0]*xx;
    if (iuser[0]==1) {
      fx = 4.0/(1.0+ruser[0]*xx*xx);
    }
    if (iuser[0]==2) {
      fx = 1.0/(xx*xx*log(ruser[0]*xx));
    }
    if (iuser[0]==3) {
      fx = exp(-ruser[0]*xx)/xx;
    }
    if (iuser[0]==4) {
      fx = ruser[0]/xx;
    }
    if (iuser[0]==5) {
      fx = exp(-3.0*ruser[0]*xx*xx-4.0*xx-1.0);
    }
    if (iuser[0]==6) {
      fx = exp(2.0*ruser[0]*xx+2.0);
    }
    if (iuser[0]<0 || iuser[0]>6) {
      iflag = -1;
    }
    fv[i] = fx;
  }

  return;
}