/* nag_rand_gen_multinomial (g05tgc) Example Program.
 *
 * Copyright 2008, Numerical Algorithms Group.
 *
 * Mark 9, 2009.
 */
/* Pre-processor includes */
#include <stdio.h>
#include <math.h>
#include <nag.h>
#include <nagx04.h>
#include <nag_stdlib.h>
#include <nagg05.h>

#define X(I, J) x[(order == Nag_ColMajor)?(J*pdx + I):(I*pdx + J)]

int main(int argc, char *argv[])
{
  FILE          *fpout;
  /* Integer scalar and array declarations */
  Integer       exit_status = 0;
  Integer       lr, x_size, i, j, lstate, pdx;
  Integer       *state = 0, *x = 0;

  /* NAG structures */
  NagError      fail;
  Nag_ModeRNG   mode;

  /* Double scalar and array declarations */
  double        p_max;
  double        *r = 0;

  /* Set the distribution parameters */
  Integer       k = 4;
  Integer       m = 6000;
  double        p[] = { 0.08e0, 0.1e0, 0.8e0, 0.02e0 };

  /* Set the sample size */
  Integer       n = 20;


  /* 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);

  /* Check for command-line IO options */
  fpout = nag_example_file_io(argc, argv, "-results", NULL);

  fprintf(fpout,
          "nag_rand_gen_multinomial (g05tgc) 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)
    {
      fprintf(fpout, "Error from nag_rand_init_repeatable (g05kfc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

  pdx = (order == Nag_ColMajor)?n:k;
  x_size = (order == Nag_ColMajor)?pdx * k:pdx * n;

  /* Calculate the size of the reference vector */
  p_max = 0.0;
  for (i = 1; i < k; i++)
    p_max = (p_max < p[i])?p[i]:p_max;
  lr = 30 + 20 * sqrt(m * p_max * (1 - p_max));

  /* Allocate arrays */
  if (!(r = NAG_ALLOC(lr, double)) ||
      !(state = NAG_ALLOC(lstate, Integer)) ||
      !(x = NAG_ALLOC(x_size, Integer)))
    {
      fprintf(fpout, "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)
    {
      fprintf(fpout, "Error from nag_rand_init_repeatable (g05kfc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

  /* Generate the variates, initialising the reference vector
     at the same time */
  mode = Nag_InitializeAndGenerate;
  nag_rand_gen_multinomial(order, mode, n, m, k, p, r, lr, state, x, pdx,
                           &fail);
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "Error from nag_rand_gen_multinomial (g05tgc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

  /* Display the variates*/
  for (i = 0; i < n; i++)
    {
      for (j = 0; j < k; j++)
        fprintf(fpout, "%12ld", X(i, j));
      fprintf(fpout, "\n");
    }

 END:
  if (fpout != stdout) fclose(fpout);
  if (r) NAG_FREE(r);
  if (state) NAG_FREE(state);
  if (x) NAG_FREE(x);

  return exit_status;
}