```/* nag_regress_confid_interval (g02cbc) Example Program.
*
* NAGPRODCODE Version.
*
* Copyright 2016 Numerical Algorithms Group.
*
* Mark 26, 2016.
*/

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

int main(void)
{
Integer exit_status = 0, i, n;
double clm, clp;
double *h = 0, *res = 0, rms, *wt = 0, *x = 0, *y = 0, *yhat = 0;
double *yl = 0, *yml = 0, *ymu = 0, *yu = 0;
char nag_enum_arg[40];
Nag_SumSquare mean;
Nag_Boolean weight;
NagError fail;

INIT_FAIL(fail);

printf("nag_regress_confid_interval (g02cbc) Example Program Results\n");
/* Skip heading in data file */
scanf("%*[^\n]");
scanf("%" NAG_IFMT "\n", &n);
scanf("%lf%lf\n", &clm, &clp);
scanf(" %39s", nag_enum_arg);
/* nag_enum_name_to_value (x04nac).
* Converts NAG enum member name to value
*/
mean = (Nag_SumSquare) nag_enum_name_to_value(nag_enum_arg);
scanf(" %39s", nag_enum_arg);
weight = (Nag_Boolean) nag_enum_name_to_value(nag_enum_arg);
if (n >= (mean == Nag_AboutMean ? 2 : 1)) {
if (!(x = NAG_ALLOC(n, double)) ||
!(y = NAG_ALLOC(n, double)) ||
!(wt = NAG_ALLOC(n, double)) ||
!(yhat = NAG_ALLOC(n, double)) ||
!(yml = NAG_ALLOC(n, double)) ||
!(ymu = NAG_ALLOC(n, double)) ||
!(yl = NAG_ALLOC(n, double)) ||
!(yu = NAG_ALLOC(n, double)) ||
!(h = NAG_ALLOC(n, double)) || !(res = NAG_ALLOC(n, double))
)
{
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
}
else {
printf("Invalid n.\n");
exit_status = 1;
return exit_status;
}
if (weight)
for (i = 0; i < n; i++)
scanf("%lf%lf%lf\n", &x[i], &y[i], &wt[i]);
else
for (i = 0; i < n; ++i)
scanf("%lf%lf\n", &x[i], &y[i]);

/* nag_regress_confid_interval (g02cbc).
* Simple linear regression confidence intervals for the
* regression line and individual points
*/
nag_regress_confid_interval(mean, n, x, y, wt, clm, clp, yhat, yml, ymu, yl,
yu, h, res, &rms, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_regress_confid_interval (g02cbc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}

printf("\ni       yhat[i]    yml[i]    ymu[i]      yl[i]      yu[i]"
" \n\n");
for (i = 0; i < n; ++i) {
printf("%" NAG_IFMT " %10.2f %10.2f", i, yhat[i], yml[i]);
printf("%10.2f  %10.2f %10.2f\n", ymu[i], yl[i], yu[i]);
}

END:
NAG_FREE(x);
NAG_FREE(y);
NAG_FREE(wt);
NAG_FREE(yhat);
NAG_FREE(yml);
NAG_FREE(ymu);
NAG_FREE(yl);
NAG_FREE(yu);
NAG_FREE(h);
NAG_FREE(res);

return exit_status;
}
```