/* nag_runs_test (g08eac) Example Program.
 *
 * Copyright 2000 Numerical Algorithms Group.
 *
 * Mark 6, 2000.
 *
 * Mark 8 revised, 2004
 */

#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     nruns, lstate;
  Integer     *state = 0;

  /* NAG structures */
  NagError    fail;

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

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

  /* Set the seed */
  Integer     seed[] = { 324213 };
  Integer     lseed = 1;

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

  /* Set the the length of the longest run */
  Integer     max_run = 6;

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

  printf("nag_runs_test (g08eac) 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;
    }

  /* 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 vector of n uniform variates between 0.0 and 1.0 */
  nag_rand_uniform(n, 0.0, 1.0, state, x, &fail);

  /* nag_runs_test (g08eac).
   * Performs the runs up or runs down test for randomness
   */
  nag_runs_test(n, x, max_run, &nruns, &chi, &df, &p, &fail);

  /* Display the results */
  if (fail.code == NE_NOERROR || fail.code == NE_G08EA_RUNS)
    {
      printf("\n");
      printf("Total number of runs found = %10ld\n", nruns);
      if (fail.code == NE_G08EA_RUNS)
        printf(
                "** Note : the number of runs requested were not found.\n");
      printf("\n");
      printf("Chisq = %10.4f\n", chi);
      printf("DF    = %8.2f\n", df);
      printf("Prob  = %10.4f\n", p);
    }
  else
    {
      printf("Error from nag_runs_test (g08eac).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }

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

  return exit_status;
}