```/* nag_glm_est_func (g02gnc) Example Program.
*
* Copyright 2014 Numerical Algorithms Group.
*
* Mark 4, 1996.
*
* Mark 6 revised, 2000.
* Mark 8 revised, 2004.
*/

#include <nag.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <nagg02.h>

#define X(I, J) x[(I) *tdx + J]
#define V(I, J) v[(I) *tdv + J]
int main(void)
{
Nag_Boolean est;
Integer     exit_status = 0, i, ip, j, m, max_iter, n, nestfn, print_iter,
rank;
Integer     *sx = 0, tdv, tdx;
NagError    fail;
double      dev, df, eps, ex_power, sestat, stat, tol, z;
double      *b = 0, *cov = 0, *f = 0, *se = 0, *v = 0, *wtptr, *x = 0;
double      *y = 0;

INIT_FAIL(fail);

printf("nag_glm_est_func (g02gnc) Example Program Results\n");
/* Skip heading in data file */
scanf("%*[^\n]");
scanf("%ld %ld %ld", &n, &m, &print_iter);

if (n >= 2 && m >= 1)
{
if (!(x = NAG_ALLOC(n*m, double)) ||
!(y = NAG_ALLOC(n, double)) ||
!(sx = NAG_ALLOC(m, Integer)))
{
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
tdx = m;
}
else
{
printf("Invalid n or m.\n");
exit_status = 1;
return exit_status;
}
wtptr = (double *) 0;
for (i = 0; i < n; i++)
{
for (j = 0; j < m; j++)
scanf("%lf", &X(i, j));
scanf("%lf", &y[i]);
}
for (j = 0; j < m; j++)
scanf("%ld", &sx[j]);
scanf("%ld", &ip);

if (!(b = NAG_ALLOC(ip, double)) ||
!(f = NAG_ALLOC(ip, double)) ||
!(v = NAG_ALLOC(n*(ip+6), double)) ||
!(cov = NAG_ALLOC(ip*(ip+1)/2, double)) ||
!(se = NAG_ALLOC(ip, double)))
{
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
tdv = ip+6;

/* Set control parameters */
max_iter = 10;
tol = 5e-5;
eps = 1e-6;
ex_power = 0.0;

/* Fit Log-linear model using nag_glm_poisson (g02gcc) */

/* nag_glm_poisson (g02gcc).
* Fits a generalized linear model with Poisson errors
*/
nag_glm_poisson(Nag_Log, Nag_MeanInclude, n, x, tdx,
m, sx, ip, y, wtptr, (double *) 0, ex_power, &dev, &df, b,
&rank, se, cov, v, tdv, tol, max_iter, print_iter, "", eps,
&fail);

if (fail.code == NE_NOERROR || fail.code == NE_LSQ_ITER_NOT_CONV ||
fail.code == NE_RANK_CHANGED || fail.code == NE_ZERO_DOF_ERROR)
{
printf("\nDeviance = %13.4e\n", dev);
printf("Degrees of freedom = %3.1f\n\n", df);
printf("       Estimate     Standard error\n\n");
for (i = 0; i < ip; i++)
printf("%14.4f%14.4f\n", b[i], se[i]);
printf("\n");
scanf("%ld", &nestfn);
for (i = 1; i <= nestfn; ++i)
{
for (j = 0; j < ip; ++j)
scanf("%lf", &f[j]);

/* nag_glm_est_func (g02gnc).
* Estimable function and the standard error of a
* generalized linear model
*/
nag_glm_est_func(ip, rank, b, cov, v,
tdv, f, &est, &stat, &sestat, &z, tol,
&fail);

if (fail.code != NE_NOERROR && fail.code != NE_RANK_EQ_IP)
{
printf("Error from nag_glm_est_func (g02gnc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}

printf("\n");
printf("Function %ld\n\n", i);
for (j = 0; j < ip; ++j)
printf("%8.2f%c", f[j],
(j%5 == 4 || j == ip-1)?'\n':' ');
printf("\n");
if (est)
printf("stat = %10.4f  sestat = %10.4f   z = %10.4f\n",
stat, sestat, z);
else
printf("Function not estimable\n");
}
}
else
{
printf("Error from nag_glm_poisson (g02gcc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}
END:
NAG_FREE(x);
NAG_FREE(y);
NAG_FREE(sx);
NAG_FREE(b);
NAG_FREE(f);
NAG_FREE(v);
NAG_FREE(cov);
NAG_FREE(se);
return exit_status;
}
```