/* nag_lapackeig_ztgsyl (f08yvc) Example Program.
*
* Copyright 2024 Numerical Algorithms Group.
*
* Mark 30.1, 2024.
*/
#include <nag.h>
#include <stdio.h>
int main(void) {
/* Scalars */
double dif, scale;
Integer i, ijob, j, m, n, pda, pdb, pdc, pdd, pde, pdf;
Integer exit_status = 0;
/* Arrays */
Complex *a = 0, *b = 0, *c = 0, *d = 0, *e = 0, *f = 0;
char nag_enum_arg[40];
/* Nag Types */
NagError fail;
Nag_OrderType order;
Nag_TransType trans;
/* K(I,J) maps matrix element (I,J) to array storage element k */
#ifdef NAG_COLUMN_MAJOR
#define K(I, J, PD) (J - 1) * PD + I - 1
order = Nag_ColMajor;
#else
#define K(I, J, PD) (I - 1) * PD + J - 1
order = Nag_RowMajor;
#endif
INIT_FAIL(fail);
printf("nag_lapackeig_ztgsyl (f08yvc) Example Program Results\n\n");
/* Skip heading in data file */
scanf("%*[^\n]");
scanf("%" NAG_IFMT "%" NAG_IFMT "%*[^\n]", &m, &n);
scanf("%" NAG_IFMT "%*[^\n]", &ijob);
if (m < 0 || n < 0 || ijob < 0 || ijob > 4) {
printf("Invalid m, n or ijob\n");
exit_status = 1;
goto END;
}
scanf(" %39s%*[^\n]", nag_enum_arg);
/* nag_enum_name_to_value (x04nac).
* Converts NAG enum member name to value
*/
trans = (Nag_TransType)nag_enum_name_to_value(nag_enum_arg);
pda = m;
pdb = n;
pdd = m;
pde = n;
#ifdef NAG_COLUMN_MAJOR
pdc = m;
pdf = m;
#else
pdc = n;
pdf = n;
#endif
/* Allocate memory */
if (!(a = NAG_ALLOC(m * m, Complex)) || !(b = NAG_ALLOC(n * n, Complex)) ||
!(c = NAG_ALLOC(m * n, Complex)) || !(d = NAG_ALLOC(m * m, Complex)) ||
!(e = NAG_ALLOC(n * n, Complex)) || !(f = NAG_ALLOC(m * n, Complex))) {
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
/* Read A, B, D, E, C and F from data file */
for (i = 1; i <= m; ++i)
for (j = 1; j <= m; ++j)
scanf(" ( %lf , %lf )", &a[K(i, j, pda)].re, &a[K(i, j, pda)].im);
scanf("%*[^\n]");
for (i = 1; i <= n; ++i)
for (j = 1; j <= n; ++j)
scanf(" ( %lf , %lf )", &b[K(i, j, pdb)].re, &b[K(i, j, pdb)].im);
scanf("%*[^\n]");
for (i = 1; i <= m; ++i)
for (j = 1; j <= m; ++j)
scanf(" ( %lf , %lf )", &d[K(i, j, pdd)].re, &d[K(i, j, pdd)].im);
scanf("%*[^\n]");
for (i = 1; i <= n; ++i)
for (j = 1; j <= n; ++j)
scanf(" ( %lf , %lf )", &e[K(i, j, pde)].re, &e[K(i, j, pde)].im);
scanf("%*[^\n]");
for (i = 1; i <= m; ++i)
for (j = 1; j <= n; ++j)
scanf(" ( %lf , %lf )", &c[K(i, j, pdc)].re, &c[K(i, j, pdc)].im);
scanf("%*[^\n]");
for (i = 1; i <= m; ++i)
for (j = 1; j <= n; ++j)
scanf(" ( %lf , %lf )", &f[K(i, j, pdf)].re, &f[K(i, j, pdf)].im);
scanf("%*[^\n]");
/* Solve the Sylvester equations:
* A*R - L*B = scale*C
* D*R - L*E = scale*F
* for R and L using nag_lapackeig_ztgsyl (f08yvc).
*/
nag_lapackeig_ztgsyl(order, trans, ijob, m, n, a, pda, b, pdb, c, pdc, d, pdd,
e, pde, f, pdf, &scale, &dif, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_lapackeig_ztgsyl (f08yvc).\n%s\n", fail.message);
exit_status = 1;
goto END;
}
/* Print the solution matrices R and L */
fflush(stdout);
nag_file_print_matrix_complex_gen_comp(
order, Nag_GeneralMatrix, Nag_NonUnitDiag, m, n, c, pdc, Nag_BracketForm,
"%7.4f", "Solution matrix R", Nag_IntegerLabels, NULL, Nag_IntegerLabels,
NULL, 80, 0, NULL, &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;
goto END;
}
printf("\n");
fflush(stdout);
nag_file_print_matrix_complex_gen_comp(
order, Nag_GeneralMatrix, Nag_NonUnitDiag, m, n, f, pdf, Nag_BracketForm,
"%7.4f", "Solution matrix L", Nag_IntegerLabels, NULL, Nag_IntegerLabels,
NULL, 80, 0, NULL, &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;
goto END;
}
printf("\nscale = %11.2e\n", scale);
if (ijob > 0 && scale > 0.0) {
printf("\ndif = %11.2e\n\n", dif);
printf("This estimate of Dif((A,D),(B,E)) was computed based on the ");
if (ijob == 1 || ijob == 3) {
printf("Frobenius norm.\n");
} else {
printf("one norm.\n");
}
}
END:
NAG_FREE(a);
NAG_FREE(b);
NAG_FREE(c);
NAG_FREE(d);
NAG_FREE(e);
NAG_FREE(f);
return exit_status;
}