/* nag_matop_complex_gen_matrix_cond_std (f01kac) Example Program.
*
* Copyright 2024 Numerical Algorithms Group.
*
* Mark 30.0, 2024.
*/
#include <math.h>
#include <nag.h>
#define A(I, J) a[J * pda + I]
int main(void) {
/* Scalars */
Integer exit_status = 0;
Integer i, j, n, pda;
double conda, cond_rel, eps, norma, normfa;
/* Arrays */
Complex *a = 0;
char nag_enum_arg[100];
/* Nag Types */
Nag_OrderType order = Nag_ColMajor;
Nag_MatFunType fun;
NagError fail;
INIT_FAIL(fail);
/* Output preamble */
printf("nag_matop_complex_gen_matrix_cond_std (f01kac) ");
printf("Example Program Results\n\n");
fflush(stdout);
/* Skip heading in data file */
scanf("%*[^\n] ");
/* Read in the problem size and the required function */
scanf("%" NAG_IFMT "%99s%*[^\n]", &n, nag_enum_arg);
pda = n;
if (!(a = NAG_ALLOC((pda) * (n), Complex))) {
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
/* nag_enum_name_to_value (x04nac)
* Converts Nag enum member name to value
*/
fun = (Nag_MatFunType)nag_enum_name_to_value(nag_enum_arg);
/* Read in the matrix A from data file */
for (i = 0; i < n; i++)
for (j = 0; j < n; j++)
scanf(" ( %lf , %lf ) ", &A(i, j).re, &A(i, j).im);
scanf("%*[^\n] ");
/* Print matrix A using nag_file_print_matrix_complex_gen (x04dac)
* Print complex general matrix (easy-to-use)
*/
nag_file_print_matrix_complex_gen(order, Nag_GeneralMatrix, Nag_NonUnitDiag,
n, n, a, pda, "A", NULL, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_file_print_matrix_complex_gen (x04dac)\n%s\n",
fail.message);
exit_status = 2;
goto END;
}
/* Find absolute condition number estimate using
* nag_matop_complex_gen_matrix_cond_std (f01kac)
* Condition number for the exponential, logarithm, sine, cosine,
* sinh or cosh of a complex matrix
*/
nag_matop_complex_gen_matrix_cond_std(fun, n, a, pda, &conda, &norma, &normfa,
&fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_matop_complex_gen_matrix_cond_std (f01kac)\n%s\n",
fail.message);
exit_status = 1;
goto END;
}
/* Print absolute condition number estimate */
printf("\nF(A) = %s(A)\n", nag_enum_arg);
printf("Estimated absolute condition number is: %7.2f\n", conda);
/* nag_machine_precision (x02ajc) The machine precision */
eps = nag_machine_precision;
/* Find relative condition number estimate */
if (normfa > eps) {
cond_rel = conda * norma / normfa;
printf("Estimated relative condition number is: %7.2f\n", cond_rel);
} else {
printf("The estimated norm of f(A) is effectively zero");
printf("and so the relative condition number is undefined.\n");
}
END:
NAG_FREE(a);
return exit_status;
}