/* nag_lapackeig_zungql (f08ctc) Example Program.
*
* Copyright 2024 Numerical Algorithms Group.
*
* Mark 30.0, 2024.
*/
#include <nag.h>
#include <stdio.h>
int main(void) {
/* Scalars */
Integer i, j, m, n, pda;
Integer exit_status = 0;
/* Arrays */
char *title = 0;
Complex *a = 0, *tau = 0;
/* Nag Types */
Nag_OrderType order;
NagError fail;
#ifdef NAG_COLUMN_MAJOR
#define A(I, J) a[(J - 1) * pda + I - 1]
order = Nag_ColMajor;
#else
#define A(I, J) a[(I - 1) * pda + J - 1]
order = Nag_RowMajor;
#endif
INIT_FAIL(fail);
printf("nag_lapackeig_zungql (f08ctc) Example Program Results\n\n");
/* Skip heading in data file */
scanf("%*[^\n]");
scanf("%" NAG_IFMT "%" NAG_IFMT "%*[^\n]", &m, &n);
#ifdef NAG_COLUMN_MAJOR
pda = m;
#else
pda = n;
#endif
/* Allocate memory */
if (!(title = NAG_ALLOC(31, char)) || !(a = NAG_ALLOC(m * n, Complex)) ||
!(tau = NAG_ALLOC(n, Complex))) {
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
/* Read A from data file */
for (i = 1; i <= m; ++i)
for (j = 1; j <= n; ++j)
scanf(" ( %lf , %lf )", &A(i, j).re, &A(i, j).im);
scanf("%*[^\n]");
/* nag_lapackeig_zgeqlf (f08csc).
* Compute the QL factorization of A.
*/
nag_lapackeig_zgeqlf(order, m, n, a, pda, tau, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_lapackeig_zgeqlf (f08csc).\n%s\n", fail.message);
exit_status = 1;
goto END;
}
/* nag_lapackeig_zungql (f08ctc).
* Form the leading n columns of Q explicitly.
*/
nag_lapackeig_zungql(order, m, n, n, a, pda, tau, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_lapackeig_zungql (f08ctc).\n%s\n", fail.message);
exit_status = 1;
goto END;
}
sprintf(title, "The leading %4" NAG_IFMT " columns of Q", n);
/* nag_file_print_matrix_complex_gen_comp (x04dbc).
* Print the leading n columns of Q.
*/
fflush(stdout);
nag_file_print_matrix_complex_gen_comp(
order, Nag_GeneralMatrix, Nag_NonUnitDiag, m, n, a, pda, Nag_BracketForm,
"%7.4f", title, Nag_IntegerLabels, 0, Nag_IntegerLabels, 0, 80, 0, 0,
&fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_file_print_matrix_complex_gen_comp (x04dbc).\n%s\n",
fail.message);
exit_status = 1;
}
END:
NAG_FREE(title);
NAG_FREE(a);
NAG_FREE(tau);
return exit_status;
}
#undef A