/* nag_rand_dist_dirichlet (g05sec) Example Program.
*
* Copyright 2024 Numerical Algorithms Group.
*
* Mark 30.0, 2024.
*/
/* Pre-processor includes */
#include <math.h>
#include <nag.h>
#include <stdio.h>
#define X(I, J) x[(order == Nag_ColMajor) ? (J * pdx + I) : (I * pdx + J)]
int main(void) {
/* Integer scalar and array declarations */
Integer exit_status = 0;
Integer pdx, x_size, i, j, lstate;
Integer *state = 0;
/* NAG structures */
NagError fail;
/* Double scalar and array declarations */
double *x = 0;
/* Set the distribution parameters */
double a[] = {2.0e0, 2.0e0, 2.0e0, 2.0e0};
Integer m = 4;
/* Set the sample size */
Integer n = 5;
/* Return the results in column major order */
Nag_OrderType order = Nag_ColMajor;
/* Choose the base generator */
Nag_BaseRNG genid = Nag_Basic;
Integer subid = 0;
/* Set the seed */
Integer seed[] = {1762543};
Integer lseed = 1;
/* Initialize the error structure */
INIT_FAIL(fail);
printf("nag_rand_dist_dirichlet (g05sec) Example Program Results\n\n");
/* Get the length of the state array */
lstate = -1;
nag_rand_init_repeat(genid, subid, seed, lseed, state, &lstate, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_rand_init_repeat (g05kfc).\n%s\n", fail.message);
exit_status = 1;
goto END;
}
pdx = (order == Nag_ColMajor) ? n : m;
x_size = (order == Nag_ColMajor) ? pdx * m : pdx * n;
/* Allocate arrays */
if (!(x = NAG_ALLOC(x_size, 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_repeat(genid, subid, seed, lseed, state, &lstate, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_rand_init_repeat (g05kfc).\n%s\n", fail.message);
exit_status = 1;
goto END;
}
/* Generate the variates */
nag_rand_dist_dirichlet(order, n, m, a, state, x, pdx, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_rand_dist_dirichlet (g05sec).\n%s\n", fail.message);
exit_status = 1;
goto END;
}
/* Display the variates */
for (i = 0; i < n; i++) {
for (j = 0; j < m; j++)
printf("%10.4f", X(i, j));
printf("\n");
}
END:
NAG_FREE(x);
NAG_FREE(state);
return exit_status;
}