/* nag_pairs_test (g08ebc) Example Program.
*
* Copyright 2017 Numerical Algorithms Group.
*
* Mark 26.1, 2017.
*
*
*/

#include <stdio.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nagg05.h>
#include <nagg08.h>

int main(void)
{
/* Integer scalar and array declarations */
Integer exit_status = 0;
Integer lstate;
Integer *state = 0;

/* NAG structures */
NagError fail;

/* Double scalar and array declarations */
double chi, df, p;
double *x = 0;

/* Choose the base generator */
Nag_BaseRNG genid = Nag_Basic;
Integer subid = 0;

/* Set the seed */
Integer seed[] = { 438532 };
Integer lseed = 1;

/* Set the size of the (randomly generated) dataset */
Integer n = 10000;

/* Set the size of the matrix of counts */
Integer max_count = 10;

/* Set the lag used when choosing pairs */
Integer lag = 1;

/* Initialize the error structure */
INIT_FAIL(fail);

printf("nag_pairs_test (g08ebc) Example Program Results\n");

/* Get the length of the state array */
lstate = -1;
nag_rand_init_repeatable(genid, subid, seed, lseed, state, &lstate, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_rand_init_repeatable (g05kfc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}

/* Allocate arrays */
if (!(x = NAG_ALLOC(n, double)) || !(state = NAG_ALLOC(lstate, Integer)))
{
printf("Allocation failure\n");
exit_status = -1;
goto END;
}

/* Initialize the generator to a repeatable sequence */
nag_rand_init_repeatable(genid, subid, seed, lseed, state, &lstate, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_rand_init_repeatable (g05kfc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}

/* Generate vector of n uniform variates between 0.0 and 1.0 */
nag_rand_basic(n, state, x, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_rand_basic (g05sac).\n%s\n", fail.message);
exit_status = 1;
goto END;
}

/* nag_pairs_test (g08ebc).
* Performs the pairs (serial) test for randomness
*/
nag_pairs_test(n, x, max_count, lag, &chi, &df, &p, &fail);

if (fail.code != NE_NOERROR && fail.code != NE_G08EB_CELL) {
printf("Error from nag_pairs_test (g08ebc).\n%s\n", fail.message);
exit_status = 1;
goto END;
}

/* Display the results */
printf("\n");
printf("\n");
printf("%s%10.4f\n", "CHISQ          = ", chi);
printf("%s%8.2f\n", "DF             = ", df);
printf("%s%10.4f\n", "Probability    = ", p);
if (fail.code == NE_G08EB_CELL)
printf("Error from nag_pairs_test (g08ebc).\n%s\n", fail.message);

END:
NAG_FREE(x);
NAG_FREE(state);

return exit_status;
}