/* F08AH_T1W_F C++ Header Example Program.
*
* Copyright 2024 Numerical Algorithms Group.
* Mark 30.0, 2024.
*/
#include <dco.hpp>
#include <iostream>
#include <math.h>
#include <nag.h>
#include <nagad.h>
#include <stdio.h>
#include <string>
using namespace std;
// typedef DCO_TYPE nagad_t1w_w_rtype
typedef double DCO_BASE_TYPE;
typedef dco::gt1s<DCO_BASE_TYPE> DCO_MODE;
typedef DCO_MODE::type DCO_TYPE;
int main()
{
/* Scalars */
Integer exit_status = 0;
cout << "F08AH_T1W_F C++ Header Example Program Results\n\n";
// Create handle
nag::ad::handle_t ad_handle;
Integer ifail = 0;
// Skip heading in data file
string mystr;
getline(cin, mystr);
Integer m, n;
cin >> m;
cin >> n;
Integer pda = m;
Integer lwork = 64 * n;
Integer tau_len;
if (m < n)
{
tau_len = m;
}
else
{
tau_len = n;
}
// Allocate arrays
// nagad_t1w_w_rtype *a = 0, *tau = 0, *a_in = 0, *work = 0;
DCO_TYPE *a = 0, *tau = 0, *work = 0, *a_in = 0;
double * l = 0, *dlda = 0;
a = new DCO_TYPE[m * n];
work = new DCO_TYPE[lwork];
a_in = new DCO_TYPE[m * n];
tau = new DCO_TYPE[tau_len];
l = new double[m * m];
dlda = new double[m * n];
// Read A from data file
double tmp;
for (int i = 0; i < m; ++i)
{
for (int j = 0; j < n; ++j)
{
cin >> tmp;
a_in[i + j * m] = tmp;
}
}
double d_zero = 0.0;
for (int i = 0; i < m * n; i++)
{
// dco::derivative(a_in[i]) = d_zero;
dco::derivative(a_in[i]) = d_zero;
a[i] = a_in[i];
}
double d_one = 1.0;
for (int j = 0; j < n; j++)
{
// dco::derivative(a[j*m]) = d_one;
dco::derivative(a[j * m]) = d_one;
nag::ad::f08ah(ad_handle, m, n, a, pda, tau, work, lwork, ifail);
if (ifail != 0)
{
printf("Error from F08AH_T1W_F .\n%" NAG_IFMT " ", ifail);
exit_status = 1;
goto END;
}
if (j == 0)
{
for (int i = 0; i < m * m; ++i)
{
// l[i] = a[i].value
l[i] = dco::value(a[i]);
}
}
for (int i = 0; i < m; i++)
{
int ld = i * (m + 1);
int k = j * m + i;
// drda[k] = a[l].tangent
dlda[k] = dco::derivative(a[ld]);
}
for (int i = 0; i < m * n; i++)
a[i] = a_in[i];
}
NagError fail;
INIT_FAIL(fail);
x04cac(Nag_ColMajor, Nag_LowerMatrix, Nag_NonUnitDiag, m, m, l, m,
"L from Q factorization of A", 0, &fail);
printf("\nDerivatives of diagonal of L w.r.t. first row of A\n");
x04cac(Nag_ColMajor, Nag_GeneralMatrix, Nag_NonUnitDiag, m, n, dlda, m,
"dL_ii/dA_j1", 0, &fail);
END:
delete[] a;
delete[] a_in;
delete[] tau;
delete[] l;
delete[] dlda;
delete[] work;
return exit_status;
}