```/* nag_lapacklin_zgbequ (f07btc) Example Program.
*
* Copyright 2019 Numerical Algorithms Group.
*
* Mark 27.0, 2019.
*/

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

int main(void)
{

/* Scalars */
double amax, big, colcnd, rowcnd, small;
Integer exit_status = 0, i, j, kl, ku, n, pdab;

/* Arrays */
Complex *ab = 0;
double *c = 0, *r = 0;

/* Nag Types */
NagError fail;
Nag_OrderType order;
Nag_Boolean scaled = Nag_FALSE;

#ifdef NAG_COLUMN_MAJOR
#define AB(I, J) ab[(J-1)*pdab + ku + I - J]
order = Nag_ColMajor;
#else
#define AB(I, J) ab[(I-1)*pdab + kl + J - I]
order = Nag_RowMajor;
#endif

INIT_FAIL(fail);

printf("nag_lapacklin_zgbequ (f07btc) Example Program Results\n\n");

/* Skip heading in data file */
scanf("%*[^\n] ");
scanf("%" NAG_IFMT "%" NAG_IFMT "%" NAG_IFMT "%*[^\n]", &n, &kl, &ku);
if (n < 0 || kl < 0 || ku < 0) {
printf("Invalid n or kl or ku\n");
exit_status = 1;
goto END;
}
/* Allocate memory */
if (!(ab = NAG_ALLOC((kl + ku + 1) * n, Complex)) ||
!(c = NAG_ALLOC(n, double)) || !(r = NAG_ALLOC(n, double)))
{
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
pdab = kl + ku + 1;

/* Read the band matrix A from data file */
for (i = 1; i <= n; ++i)
for (j = MAX(i - kl, 1); j <= MIN(i + ku, n); ++j)
scanf(" ( %lf , %lf )", &AB(i, j).re, &AB(i, j).im);
scanf("%*[^\n]");

/* Print the matrix A using nag_file_print_matrix_complex_band (x04dec). */
fflush(stdout);
nag_file_print_matrix_complex_band(order, n, n, kl, ku, ab, pdab, "Matrix A", 0,
&fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_file_print_matrix_complex_band (x04dec).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}
printf("\n");

/* Compute row and column scaling factors using nag_lapacklin_zgbequ (f07btc). */
nag_lapacklin_zgbequ(order, n, n, kl, ku, ab, pdab, r, c, &rowcnd, &colcnd, &amax,
&fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_lapacklin_zgbequ (f07btc).\n%s\n", fail.message);
exit_status = 1;
goto END;
}

/* Print rowcnd, colcnd, amax and the scale factors */
printf("rowcnd = %10.1e, colcnd = %10.1e, amax = %10.1e\n\n", rowcnd,
colcnd, amax);
printf("Row scale factors\n");
for (i = 1; i <= n; ++i)
printf("%11.2e%s", r[i - 1], i % 7 == 0 ? "\n" : " ");

printf("\n\nColumn scale factors\n");
for (i = 1; i <= n; ++i)
printf("%11.2e%s", c[i - 1], i % 7 == 0 ? "\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. / small;

if (colcnd < 0.1) {
scaled = Nag_TRUE;
/* column scale A */
for (j = 1; j <= n; ++j)
for (i = MAX(1, j - ku); i <= MIN(n, j + kl); ++i) {
AB(i, j).re *= c[j - 1];
AB(i, j).im *= c[j - 1];
}
}
if (rowcnd < 0.1 || amax < small || amax > big) {
/* row scale A */
scaled = Nag_TRUE;
for (j = 1; j <= n; ++j)
for (i = MAX(1, j - ku); i <= MIN(n, j + kl); ++i) {
AB(i, j).re *= r[i - 1];
AB(i, j).im *= r[i - 1];
}
}
if (scaled) {
/* Print the row and column scaled matrix using
* nag_file_print_matrix_complex_band (x04dec).
*/
fflush(stdout);
nag_file_print_matrix_complex_band(order, n, n, kl, ku, ab, pdab, "Scaled matrix",
0, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_file_print_matrix_complex_band (x04dec).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}
}
END:
NAG_FREE(ab);
NAG_FREE(c);
NAG_FREE(r);

return exit_status;
}

#undef AB
```