NAG Library Manual, Mark 28.5
```/* nag_lapackeig_dorgql (f08cfc) Example Program.
*
* Copyright 2022 Numerical Algorithms Group.
*
* Mark 28.5, 2022.
*/

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

int main(void) {
/* Scalars */
Integer i, j, m, n, pda;
Integer exit_status = 0;
/* Arrays */
char *title = 0;
double *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_dorgql (f08cfc) 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, double)) ||
!(tau = NAG_ALLOC(n, double))) {
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", &A(i, j));
scanf("%*[^\n]");

/* nag_lapackeig_dgeqlf (f08cec).
* Compute the QL factorization of A .
*/
nag_lapackeig_dgeqlf(order, m, n, a, pda, tau, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_lapackeig_dgeqlf (f08cec).\n%s\n", fail.message);
exit_status = 1;
goto END;
}

/* nag_lapackeig_dorgql (f08cfc).
* Form the leading n columns of Q explicitly.
*/
nag_lapackeig_dorgql(order, m, n, n, a, pda, tau, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_lapackeig_dorgql (f08cfc).\n%s\n", fail.message);
exit_status = 1;
goto END;
}

/* Form the heading for x04cac */
sprintf(title, "The leading %4" NAG_IFMT " columns of Q", n);

/* nag_file_print_matrix_real_gen (x04cac).
* Print the leading n columns of Q.
*/
fflush(stdout);
nag_file_print_matrix_real_gen(order, Nag_GeneralMatrix, Nag_NonUnitDiag, m,
n, a, pda, title, 0, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_file_print_matrix_real_gen (x04cac).\n%s\n",
fail.message);
exit_status = 1;
}

END:
NAG_FREE(title);
NAG_FREE(a);
NAG_FREE(tau);

return exit_status;
}

#undef A
```