/* nag_sparse_nsym_sol (f11dec) Example Program.
*
* Copyright 2017 Numerical Algorithms Group.
*
* Mark 26.1, 2017.
*/
#include <nag.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <nag_string.h>
#include <nagf11.h>
int main(void)
{
double *a = 0, *b = 0, *x = 0;
double omega;
double rnorm;
double tol;
Integer exit_status = 0;
Integer *icol = 0, *irow = 0;
Integer i, m, n;
Integer maxitn, itn;
Integer nnz;
char nag_enum_arg[40];
Nag_SparseNsym_Method method;
Nag_SparseNsym_PrecType precon;
Nag_Sparse_Comm comm;
NagError fail;
INIT_FAIL(fail);
printf("nag_sparse_nsym_sol (f11dec) Example Program Results\n");
/* Skip heading in data file */
scanf("%*[^\n]");
scanf("%" NAG_IFMT "%*[^\n]", &n);
scanf("%" NAG_IFMT "%*[^\n]", &nnz);
scanf("%39s", nag_enum_arg);
/* nag_enum_name_to_value (x04nac).
* Converts NAG enum member name to value
*/
method = (Nag_SparseNsym_Method) nag_enum_name_to_value(nag_enum_arg);
scanf("%39s%*[^\n]", nag_enum_arg);
precon = (Nag_SparseNsym_PrecType) nag_enum_name_to_value(nag_enum_arg);
scanf("%lf%*[^\n]", &omega);
scanf("%" NAG_IFMT "%lf%" NAG_IFMT "%*[^\n]", &m, &tol, &maxitn);
x = NAG_ALLOC(n, double);
b = NAG_ALLOC(n, double);
a = NAG_ALLOC(nnz, double);
irow = NAG_ALLOC(nnz, Integer);
icol = NAG_ALLOC(nnz, Integer);
if (!irow || !icol || !a || !x || !b) {
printf("Allocation failure\n");
exit_status = 1;
goto END;
}
/* Read the matrix a */
for (i = 1; i <= nnz; ++i)
scanf("%lf%" NAG_IFMT "%" NAG_IFMT "%*[^\n]", &a[i - 1], &irow[i - 1],
&icol[i - 1]);
/* Read right-hand side vector b and initial approximate solution x */
for (i = 1; i <= n; ++i)
scanf("%lf", &b[i - 1]);
scanf("%*[^\n]");
for (i = 1; i <= n; ++i)
scanf("%lf", &x[i - 1]);
scanf("%*[^\n]");
/* Solve Ax = b using nag_sparse_nsym_sol (f11dec) */
/* nag_sparse_nsym_sol (f11dec).
* Solver with no Jacobi/SSOR preconditioning (nonsymmetric)
*/
nag_sparse_nsym_sol(method, precon, n, nnz, a, irow, icol, omega, b, m, tol,
maxitn, x, &rnorm, &itn, &comm, &fail);
printf("%s%10" NAG_IFMT "%s\n", "Converged in", itn, " iterations");
printf("%s%16.3e\n", "Final residual norm =", rnorm);
/* Output x */
printf(" x\n");
for (i = 1; i <= n; ++i)
printf(" %16.6e\n", x[i - 1]);
END:
NAG_FREE(irow);
NAG_FREE(icol);
NAG_FREE(a);
NAG_FREE(x);
NAG_FREE(b);
return exit_status;
}