/* nag_sparse_nherm_sol (f11dsc) Example Program.
*
* Copyright 2014 Numerical Algorithms Group.
*
* Mark 23, 2011.
*/
#include <nag.h>
#include <nag_stdlib.h>
#include <naga02.h>
#include <nagf11.h>
int main(void)
{
/* Scalars */
Integer exit_status = 0;
double omega, rnorm, tol;
Integer i, itn, m, maxitn, n, nnz;
/* Arrays */
Complex *a = 0, *b = 0, *x = 0;
Integer *icol = 0, *irow = 0;
char nag_enum_arg[40];
/* NAG types */
Nag_SparseNsym_Method method;
Nag_SparseNsym_PrecType precon;
NagError fail;
INIT_FAIL(fail);
printf("nag_sparse_nherm_sol (f11dsc) Example Program Results\n\n");
/* Skip heading in data file*/
scanf("%*[^\n]");
scanf("%ld%*[^\n]", &n);
scanf("%ld%*[^\n]", &nnz);
scanf("%39s%*[^\n]", 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("%ld%lf%ld%*[^\n]", &m, &tol, &maxitn);
if (
!(a = NAG_ALLOC((nnz), Complex)) ||
!(b = NAG_ALLOC((n), Complex)) ||
!(x = NAG_ALLOC((n), Complex)) ||
!(icol = NAG_ALLOC((nnz), Integer)) ||
!(irow = NAG_ALLOC((nnz), Integer))
) {
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
/* Read the matrix A*/
for (i = 0; i < nnz; i++)
scanf(" ( %lf , %lf ) %ld%ld%*[^\n] ",
&a[i].re, &a[i].im, &irow[i], &icol[i]);
/* Read rhs vector b and initial approximate solution x*/
for (i = 0; i < n; i++) scanf(" ( %lf , %lf ) ", &b[i].re, &b[i].im);
scanf("%*[^\n]");
for (i = 0; i < n; i++) scanf(" ( %lf , %lf ) ", &x[i].re, &x[i].im);
/* solve ax = b */
/* nag_sparse_nherm_sol (f11dsc).
* Solution of complex sparse non-Hermitian linear system, RGMRES, CGS,
* Bi-CGSTAB or TFQMR method, Jacobi or SSOR preconditioner Black Box.
*/
nag_sparse_nherm_sol(method, precon, n, nnz, a, irow, icol, omega, b, m, tol,
maxitn, x, &rnorm, &itn, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_sparse_nherm_sol (f11dsc).\n%s\n", fail.message);
exit_status = 1;
goto END;
}
printf("Converged in%13ld iterations\n", itn);
printf("Final residual norm = %11.3e\n\n", rnorm);
/* Output x*/
printf("%14s\n","Solution");
for (i = 0; i < n; i++) printf("(%13.4e, %13.4e)\n", x[i].re, x[i].im);
END:
NAG_FREE(a);
NAG_FREE(b);
NAG_FREE(x);
NAG_FREE(icol);
NAG_FREE(irow);
return exit_status;
}