/* nag_zppequ (f07gtc) Example Program.
*
* Copyright 2014 Numerical Algorithms Group.
*
* Mark 23, 2011.
*/
#include <stdio.h>
#include <nag.h>
#include <nagx04.h>
#include <nag_stdlib.h>
#include <nagf07.h>
#include <nagx02.h>
int main(void)
{
/* Scalars */
double amax, big, scond, small;
Integer exit_status = 0, i, j, n;
/* Arrays */
Complex *ap = 0;
double *s = 0;
char nag_enum_arg[40];
/* Nag Types */
NagError fail;
Nag_OrderType order;
Nag_UploType uplo;
#ifdef NAG_COLUMN_MAJOR
#define A_UPPER(I, J) ap[J*(J-1)/2 + I - 1]
#define A_LOWER(I, J) ap[(2*n-J)*(J-1)/2 + I - 1]
order = Nag_ColMajor;
#else
#define A_LOWER(I, J) ap[I*(I-1)/2 + J - 1]
#define A_UPPER(I, J) ap[(2*n-I)*(I-1)/2 + J - 1]
order = Nag_RowMajor;
#endif
INIT_FAIL(fail);
printf("nag_zppequ (f07gtc) Example Program Results\n\n");
/* Skip heading in data file */
scanf("%*[^\n]");
scanf("%ld%*[^\n]", &n);
if (n < 0)
{
printf("Invalid n\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
*/
uplo = (Nag_UploType) nag_enum_name_to_value(nag_enum_arg);
/* Allocate memory */
if (!(ap = NAG_ALLOC(n*(n+1)/2, Complex)) ||
!(s = NAG_ALLOC(n, double)))
{
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
/* Read the upper or lower triangular part of the matrix A from data file */
if (uplo == Nag_Upper)
for (i = 1; i <= n; ++i)
for (j = i; j <= n; ++j)
scanf(" ( %lf , %lf )", &A_UPPER(i, j).re, &A_UPPER(i, j).im);
else if (uplo == Nag_Lower)
for (i = 1; i <= n; ++i)
for (j = 1; j <= i; ++j)
scanf(" ( %lf , %lf )", &A_LOWER(i, j).re, &A_LOWER(i, j).im);
scanf("%*[^\n]");
/* Print the matrix A using nag_pack_complx_mat_print_comp (x04ddc). */
fflush(stdout);
nag_pack_complx_mat_print_comp(order, uplo, Nag_NonUnitDiag, n, ap,
Nag_BracketForm, "%11.2e", "Matrix A",
Nag_IntegerLabels, 0, Nag_IntegerLabels, 0,
80, 0, 0, &fail);
if (fail.code != NE_NOERROR)
{
printf("Error from nag_pack_complx_mat_print_comp (x04ddc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}
printf("\n");
/* Compute diagonal scaling factors using nag_zppequ (f07gtc). */
nag_zppequ(order, uplo, n, ap, s, &scond, &amax, &fail);
if (fail.code != NE_NOERROR)
{
printf("Error from nag_zppequ (f07gtc).\n%s\n", fail.message);
exit_status = 1;
goto END;
}
/* Print scond, amax and the scale factors */
printf("scond = %10.1e, amax = %10.1e\n", scond, amax);
printf("\nDiagonal scaling factors\n");
for (i = 0; i < n; ++i) printf("%11.1e%s", s[i], i%6 == 5?"\n":" ");
printf("\n\n");
/* Compute values close to underflow and overflow using
* nag_real_safe_small_number (x02amc), nag_machine_precision (x02ajc) and
* nag_real_base (x02bhc)
*/
small = nag_real_safe_small_number / (nag_machine_precision * nag_real_base);
big = 1.0 / small;
if (scond < 0.1 || amax < small || amax > big)
{
/* Scale A */
if (uplo == Nag_Upper)
for (j = 1; j <= n; ++j)
for (i = 1; i <= j; ++i)
{
A_UPPER(i, j).re *= s[i-1] * s[j-1];
A_UPPER(i, j).im *= s[i-1] * s[j-1];
}
else
for (j = 1; j <= n; ++j)
for (i = j; i <= n; ++i)
{
A_LOWER(i, j).re *= s[i-1] * s[j-1];
A_LOWER(i, j).im *= s[i-1] * s[j-1];
}
/* Print the scaled matrix using
* nag_pack_complx_mat_print_comp (x04ddc).
*/
fflush(stdout);
nag_pack_complx_mat_print_comp(order, uplo, Nag_NonUnitDiag, n, ap,
Nag_BracketForm, 0, "Scaled matrix",
Nag_IntegerLabels, 0, Nag_IntegerLabels,
0, 80, 0, 0, &fail);
if (fail.code != NE_NOERROR)
{
printf("Error from nag_pack_complx_mat_print_comp (x04ddc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}
}
END:
NAG_FREE(ap);
NAG_FREE(s);
return exit_status;
}
#undef A_UPPER
#undef A_LOWER