/* F03BN_T1W_F C++ Header Example Program.
*
* Copyright 2024 Numerical Algorithms Group.
* Mark 30.1, 2024.
*/
#include <dco.hpp>
#include <iostream>
#include <nag.h>
#include <nagad.h>
#include <nagx04.h>
#include <stdio.h>
#include <string>
using namespace std;
int main()
{
int exit_status = 0;
nag::ad::handle_t ad_handle;
Integer ifail = 0;
cout << "F03BN_T1W_F C++ Header Example Program Results\n\n";
// Skip heading in data file
string mystr;
getline(cin, mystr);
// Read problem size and number of right-hand-sides
Integer n;
cin >> n;
// Allocate arrays containing A and its factorized form, B
// and the solution X.
nagad_t1w_w_ctype *a = 0, *a_in = 0;
nagad_t1w_w_rtype *a_r = 0, *a_i = 0;
Complex * ar = 0;
Integer * ipiv = 0;
a = new nagad_t1w_w_ctype[n * n];
a_in = new nagad_t1w_w_ctype[n * n];
a_r = new nagad_t1w_w_rtype[n * n];
a_i = new nagad_t1w_w_rtype[n * n];
ipiv = new Integer[n];
ar = new Complex[n * n];
// Read the matrix A, register and copy
double dr, di;
for (int i = 0; i < n; ++i)
{
for (int j = 0; j < n; ++j)
{
cin >> dr >> di;
Integer k = i + j * n;
a_r[k] = dr;
a_i[k] = di;
ar[k].re = dr;
ar[k].im = di;
}
}
// Print matrix A
cout << endl;
NagError fail;
INIT_FAIL(fail);
x04dac(Nag_ColMajor, Nag_GeneralMatrix, Nag_NonUnitDiag, n, n, ar, n, " A",
0, &fail);
// Create AD configuration data object
ifail = 0;
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n; j++)
{
Integer k = i + j * n;
for (int r = 0; r < 2; ++r)
{
double inc = 1.0;
if (r == 0)
{
dco::derivative(a_r[k]) = inc;
}
else
{
dco::derivative(a_i[k]) = inc;
}
for (int p = 0; p < n; ++p)
{
for (int q = 0; q < n; ++q)
{
Integer l = p + q * n;
a[l].real(a_r[l]);
a[l].imag(a_i[l]);
}
}
// Factorize the matrix A
ifail = 0;
nag::ad::f07ar(ad_handle, n, n, a, n, ipiv, ifail);
if (i == 0 && j == 0 && r == 0)
{
// Print Factorization of A
for (int p = 0; p < n; p++)
{
for (int q = 0; q < n; q++)
{
int l = p + q * n;
nagad_t1w_w_rtype akr, aki;
akr = real(a[l]);
aki = imag(a[l]);
ar[l].re = dco::value(akr);
ar[l].im = dco::value(aki);
}
}
cout << endl;
// NagError fail;
INIT_FAIL(fail);
x04dac(Nag_ColMajor, Nag_GeneralMatrix, Nag_NonUnitDiag, n, n, ar, n,
" Array A after factorization", 0, &fail);
}
nagad_t1w_w_ctype d;
Integer id[2];
d = 0;
ifail = 0;
nag::ad::f03bn(ad_handle, n, a, n, ipiv, d, id, ifail);
if (i == 0 && j == 0 && r == 0)
{
nagad_t1w_w_rtype dcr, dci;
dcr = real(d);
dci = imag(d);
dr = dco::value(dcr);
di = dco::value(dci);
cout << " d = (" << dr << "," << di << ") id = ";
cout << id[0] << ", " << id[1];
dr = dr * pow(2.0, id[0]);
di = di * pow(2.0, id[1]);
cout << "\n\n value of determinant = (" << dr << "," << di << ")";
cout << endl;
}
// Obtain derivatives
nagad_t1w_w_rtype dt;
dt = real(d);
double ddr = dco::derivative(dt);
double zero = 0.0;
if (r == 0)
{
ar[k].re = ddr;
dco::derivative(a_r[k]) = zero;
}
else
{
ar[k].im = ddr;
dco::derivative(a_i[k]) = zero;
}
}
}
}
cout << "\n\n Derivatives calculated: First order tangents\n";
cout << " Computational mode : algorithmic\n";
cout << "\n Derivatives of real(d) w.r.t A:\n";
// Print derivatives
cout << endl;
INIT_FAIL(fail);
x04dac(Nag_ColMajor, Nag_GeneralMatrix, Nag_NonUnitDiag, n, n, ar, n,
" d(dreal)/da(i,j)", 0, &fail);
END:
ifail = 0;
delete[] a;
delete[] a_in;
delete[] a_r;
delete[] a_i;
delete[] ipiv;
delete[] ar;
return exit_status;
}