/* nag_rand_dirichlet (g05sec) Example Program.
 *
 * Copyright 2008, Numerical Algorithms Group.
 *
 * Mark 9, 2009.
 */
/* Pre-processor includes */
#include <stdio.h>
#include <math.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nagg05.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;

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

  printf("nag_rand_dirichlet (g05sec) Example Program Results\n\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;
    }

  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;
    }

  /* Initialise 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 the variates*/
  nag_rand_dirichlet(order, n, m, a, state, x, pdx, &fail);
  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_rand_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:
  if (x) NAG_FREE(x);
  if (state) NAG_FREE(state);

  return exit_status;
}