/* nag_contab_chisq (g11aac) Example Program.
*
* Copyright 2024 Numerical Algorithms Group.
*
* Mark 30.0, 2024.
*
*/
#include <nag.h>
#include <stdio.h>
#define NOBST(I, J) nobst[(I)*tdnobs + J]
int main(void) {
Integer exit_status = 0, i, j, ncol, *nobst = 0, nrow, tdnobs;
NagError fail;
double chi, *chist = 0, df, *expt = 0, g, prob;
INIT_FAIL(fail);
printf("nag_contab_chisq (g11aac) Example Program Results\n\n");
/* Skip heading in data file */
scanf("%*[^\n] ");
scanf("%" NAG_IFMT " %" NAG_IFMT " %*[^\n] ", &nrow, &ncol);
if (nrow >= 2 && ncol >= 2) {
if (!(expt = NAG_ALLOC((nrow) * (ncol), double)) ||
!(chist = NAG_ALLOC((nrow) * (ncol), double)) ||
!(nobst = NAG_ALLOC((nrow) * (ncol), Integer))) {
printf("Allocation failure\n");
exit_status = -1;
goto END;
}
tdnobs = ncol;
} else {
printf("Invalid nrow or ncol.\n");
exit_status = 1;
return exit_status;
}
for (i = 0; i < nrow; ++i) {
for (j = 0; j < ncol; ++j)
scanf("%" NAG_IFMT "", &NOBST(i, j));
scanf("%*[^\n]");
}
/* nag_contab_chisq (g11aac).
* chi^2 statistics for two-way contingency table
*/
nag_contab_chisq(nrow, ncol, nobst, tdnobs, expt, chist, &prob, &chi, &g, &df,
&fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_contab_chisq (g11aac).\n%s\n", fail.message);
exit_status = 1;
goto END;
}
printf("Probability = %6.4f\n", prob);
printf("Pearson Chi-square statistic = %8.3f\n", chi);
printf("Likelihood ratio test statistic = %8.3f\n", g);
printf("Degrees of freedom = %4.0f\n", df);
END:
NAG_FREE(expt);
NAG_FREE(chist);
NAG_FREE(nobst);
return exit_status;
}