/* D01PA_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;

extern "C"
{
  static void NAG_CALL fun(void* &ad_handle,
                              const Integer& ndim,
                              const nagad_t1w_w_rtype x[],
                              nagad_t1w_w_rtype& ret,
                              Integer iuser[],
                              nagad_t1w_w_rtype ruser[]);
}

int main(void)
{
  // Scalars
  int               exit_status = 0;
  Integer           mxord = 5, ndim = 3, sdvert = 8, ldvert = 4;

  cout << "D01PA_T1W_F C++ Header Example Program Results\n\n";

  // Allocate memory
  nagad_t1w_w_rtype *finvls = 0, *vert = 0, *vert_in = 0;
  finvls  = new nagad_t1w_w_rtype [mxord];
  vert    = new nagad_t1w_w_rtype [ldvert*sdvert];
  vert_in = new nagad_t1w_w_rtype [ldvert*ndim];

  for (int i=0;i<ndim*ldvert;i++) {
    vert_in[i] = 0.0;
  }
  for (int i=1;i<ndim*ldvert;i=i+ldvert+1) {
    vert_in[i] = 1.0;
  }

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

  for (int i=0;i<ndim*ldvert;i++) {
    vert[i] = vert_in[i];
  }
  
  cout << "\n Maxord   Estimated      Estimated         Integrand\n";
  cout << "           value         accuracy        evaluations\n";
  cout.setf(ios::scientific,ios::floatfield);
  cout.precision(4);

  Integer minord = 0, nevals = 1;
  for (Integer maxord = 1; maxord<=mxord; maxord++) {
      
    // Call the AD routine
    nagad_t1w_w_rtype esterr, ruser[1];
    Integer           iuser[1];
    ifail = 0;
    d01pa_t1w_f_(ad_handle,ndim,vert,ldvert,sdvert,fun,minord,
                 maxord,finvls,esterr,iuser,ruser,ifail);
    double finv_r = nagad_t1w_get_value(finvls[maxord-1]);
    double estr_r = nagad_t1w_get_value(esterr);
    cout.width(5); cout << maxord;
    cout.width(15); cout << finv_r;
    cout.width(15); cout << estr_r;
    cout.width(12); cout << nevals << endl;
      
    nevals = (nevals*(maxord+ndim+1))/maxord;
  }

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

  nagad_t1w_w_rtype sol = finvls[mxord-1];
  
  cout.setf(ios::right);
  cout.precision(4);
  cout << "\n Solution, I = ";
  double ans_value = nagad_t1w_get_value(finvls[mxord-1]);
  cout.width(12); cout << ans_value << endl;
  
  cout << "\n Derivatives w.r.t vertices:\n";
  cout << "   i   j    d/dv(i,j)\n";

  cout.setf(ios::scientific,ios::floatfield);

  int k = -1;
  for (int i = 1; i <= ndim+1; i++) {
    for (int j = 1; j <= ndim; j++) {
      k = k + 1;

      double inc = 1.0;
      nagad_t1w_inc_derivative(&vert[k],inc);
      ifail = 0;
      minord = 0;

      // Call the AD routine
      nagad_t1w_w_rtype esterr, ruser[1];
      Integer           iuser[1];
      ifail = 0;
      d01pa_t1w_f_(ad_handle,ndim,vert,ldvert,sdvert,fun,minord,
                   mxord,finvls,esterr,iuser,ruser,ifail);
      
      double dfdv = nagad_t1w_get_derivative(finvls[mxord-1]);
      double zero = 0.0;
      nagad_t1w_set_derivative(&vert[k],zero);
      
      cout.width(4); cout << i;
      cout.width(4); cout << j;
      cout.width(14); cout << dfdv << endl;
    }
  }

  // Remove computational data object
  ifail = 0;
  x10ab_t1w_f_(ad_handle,ifail);

  delete [] finvls;
  delete [] vert;
  delete [] vert_in;
  return exit_status;
}
static void NAG_CALL fun(void* &ad_handle,
                         const Integer& ndim,
                         const nagad_t1w_w_rtype x[],
                         nagad_t1w_w_rtype& ret,
                         Integer iuser[],
                         nagad_t1w_w_rtype ruser[])
{
  nagad_t1w_w_rtype tmp1;
  // dco/c++ used here to perform AD of the following
  tmp1 = x[0] + x[1] + x[2];
  ret = exp(tmp1)*cos(tmp1);
  return;
}