/* F11DB_P0W_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>
using namespace std;
int main()
{
int exit_status = 0;
nag::ad::handle_t ad_handle;
Integer ifail = 0;
cout << "F11DB_P0W_F C++ Header Example Program Results\n\n";
// Skip heading in data file
string mystr;
getline(cin, mystr);
// Read order of matrix and number of nonzero entries
Integer n, nnz;
cin >> n;
cin >> nnz;
Integer la = 2 * nnz;
Integer liwork = 7 * n + 2;
double * a = 0, *x = 0, *y = 0;
Integer *icol = 0, *idiag = 0, *ipivp = 0, *ipivq = 0, *irow = 0;
Integer *istr = 0, *iwork = 0;
a = new double[la];
x = new double[n];
y = new double[n];
icol = new Integer[la];
idiag = new Integer[n];
ipivp = new Integer[n];
ipivq = new Integer[n];
irow = new Integer[la];
istr = new Integer[n + 1];
iwork = new Integer[liwork];
// Read the matrix A
for (int i = 0; i < nnz; i++)
{
cin >> a[i] >> irow[i] >> icol[i];
}
// Read the vector y
for (int i = 0; i < n; i++)
{
cin >> y[i];
}
ifail = 0;
// Calculate LU factorization
Integer lfill = -1;
double dtol;
Integer nnzc, npivm;
dtol = 0.0;
ifail = 0;
nag::ad::f11da(ad_handle, n, nnz, a, la, irow, icol, lfill, dtol, "C", "N",
ipivp, ipivq, istr, idiag, nnzc, npivm, iwork, liwork, ifail);
// Check value of npivm
if (npivm > 0)
{
cout << " Factorization is not complete" << endl;
}
else
{
// Solve P L D U x = y
ifail = 0;
nag::ad::f11db(ad_handle, "N", n, a, la, irow, icol, ipivp, ipivq, istr,
idiag, "C", y, x, ifail);
// Output results
cout.setf(ios::scientific, ios::floatfield);
cout.precision(4);
cout << " Solution vector" << endl;
for (int i = 0; i < n; ++i)
{
cout.width(12);
cout << x[i] << " ";
}
cout << endl;
}
delete[] a;
delete[] x;
delete[] y;
delete[] icol;
delete[] idiag;
delete[] ipivp;
delete[] ipivq;
delete[] irow;
delete[] istr;
delete[] iwork;
return exit_status;
}