NAG Library Manual, Mark 27.2
```/* nag_lapacklin_zpoequ (f07ftc) Example Program.
*
* Copyright 2021 Numerical Algorithms Group.
*
* Mark 27.2, 2021.
*/

#include <nag.h>
#include <stdio.h>

int main(void) {
/* Scalars */
double amax, big, scond, small;
Integer i, j, n, pda;
Integer exit_status = 0;
/* Arrays */
Complex *a = 0;
double *s = 0;

/* Nag Types */
NagError fail;
Nag_OrderType order;

#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_lapacklin_zpoequ (f07ftc) Example Program Results\n\n");

/* Skip heading in data file */
scanf("%*[^\n]");
scanf("%" NAG_IFMT "%*[^\n]", &n);

pda = n;
/* Allocate memory */
if (!(a = NAG_ALLOC(n * n, Complex)) || !(s = NAG_ALLOC(n, double))) {
printf("Allocation failure\n");
exit_status = -1;
goto END;
}

/* Read the upper triangular part of the matrix A from data file */
for (i = 1; i <= n; ++i)
for (j = i; j <= n; ++j)
scanf(" ( %lf , %lf )", &A(i, j).re, &A(i, j).im);
scanf("%*[^\n]");

/* Print the matrix A using nag_file_print_matrix_complex_gen_comp (x04dbc).
*/
fflush(stdout);
nag_file_print_matrix_complex_gen_comp(
order, Nag_UpperMatrix, Nag_NonUnitDiag, n, n, a, pda, 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_file_print_matrix_complex_gen_comp (x04dbc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}
printf("\n");

/* Compute diagonal scaling factors using nag_lapacklin_zpoequ (f07ftc). */
nag_lapacklin_zpoequ(order, n, a, pda, s, &scond, &amax, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_lapacklin_zpoequ (f07ftc).\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 % 7 == 6 ? "\n" : " ");
printf("\n\n");

/* Compute values close to underflow and overflow using
* nag_machine_real_safe (x02amc), nag_machine_precision (x02ajc) and
* nag_machine_model_base (x02bhc)
*/
small =
nag_machine_real_safe / (nag_machine_precision * nag_machine_model_base);
big = 1.0 / small;
if (scond < 0.1 || amax < small || amax > big) {
/* Scale A */
for (j = 1; j <= n; ++j)
for (i = 1; i <= j; ++i) {
A(i, j).re *= s[i - 1] * s[j - 1];
A(i, j).im *= s[i - 1] * s[j - 1];
}

/* Print the scaled matrix using
* nag_file_print_matrix_complex_gen_comp (x04dbc).
*/
fflush(stdout);
nag_file_print_matrix_complex_gen_comp(
order, Nag_UpperMatrix, Nag_NonUnitDiag, n, n, a, pda, Nag_BracketForm,
0, "Scaled matrix", 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;
goto END;
}
}

END:
NAG_FREE(a);
NAG_FREE(s);

return exit_status;
}

#undef A
```