/* nag_sparse_direct_real_gen_setup (f11mdc) Example Program.
*
* Copyright 2024 Numerical Algorithms Group.
*
* Mark 30.3, 2024.
*/
#include <nag.h>
#include <stdio.h>
int main(void) {
Integer exit_status = 0, i, n, nnz;
Integer *icolzp = 0, *iprm = 0, *irowix = 0;
/* Nag types */
Nag_ColumnPermutationType ispec;
NagError fail;
INIT_FAIL(fail);
printf("nag_sparse_direct_real_gen_setup (f11mdc) Example Program Results"
"\n\n");
/* Skip heading in data file */
scanf("%*[^\n] ");
/* Read order of matrix */
scanf("%" NAG_IFMT "%*[^\n] ", &n);
if (!(icolzp = NAG_ALLOC(n + 1, Integer))) {
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
/* Read the matrix A */
for (i = 1; i <= n + 1; ++i)
scanf("%" NAG_IFMT "%*[^\n] ", &icolzp[i - 1]);
nnz = icolzp[n] - 1;
if (!(irowix = NAG_ALLOC(nnz, Integer)) ||
!(iprm = NAG_ALLOC(7 * n, Integer))) {
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
for (i = 1; i <= nnz; ++i)
scanf("%" NAG_IFMT "%*[^\n] ", &irowix[i - 1]);
/* Calculate COLAMD permutation */
ispec = Nag_Sparse_Colamd;
/* nag_sparse_direct_real_gen_setup (f11mdc).
* Real sparse nonsymmetric linear systems, setup for
* nag_sparse_direct_real_gen_lu (f11mec)
*/
nag_sparse_direct_real_gen_setup(ispec, n, icolzp, irowix, iprm, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_sparse_direct_real_gen_setup (f11mdc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}
/* Output results */
printf("\n");
printf("%s\n", "COLAMD Permutation");
for (i = 1; i <= n; ++i)
printf("%6" NAG_IFMT "%s", iprm[n + i - 1],
i % 10 == 0 || i == n ? "\n" : " ");
/* Calculate user permutation */
ispec = Nag_Sparse_User;
iprm[0] = 4;
iprm[1] = 3;
iprm[2] = 2;
iprm[3] = 1;
iprm[4] = 0;
/* nag_sparse_direct_real_gen_setup (f11mdc), see above. */
nag_sparse_direct_real_gen_setup(ispec, n, icolzp, irowix, iprm, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_sparse_direct_real_gen_setup (f11mdc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}
/* Output results */
printf("\n");
printf("%s", "User Permutation");
printf("\n");
for (i = 1; i <= n; ++i)
printf("%6" NAG_IFMT "%s", iprm[n + i - 1],
i % 10 == 0 || i == n ? "\n" : " ");
/* Calculate natural permutation */
ispec = Nag_Sparse_Identity;
/* nag_sparse_direct_real_gen_setup (f11mdc), see above. */
nag_sparse_direct_real_gen_setup(ispec, n, icolzp, irowix, iprm, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_sparse_direct_real_gen_setup (f11mdc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}
/* Output results */
printf("\n");
printf("%s\n", "Natural Permutation");
for (i = 1; i <= n; ++i)
printf("%6" NAG_IFMT "%s", iprm[n + i - 1],
i % 10 == 0 || i == n ? "\n" : " ");
printf("\n");
END:
NAG_FREE(icolzp);
NAG_FREE(iprm);
NAG_FREE(irowix);
return exit_status;
}