/* nag_gaps_test (g08edc) 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     lstate;
  Integer     *state = 0;

  /* NAG structures */
  NagError    fail;

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

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

  /* Set the seed */
  Integer     seed[] = { 424232 };
  Integer     lseed = 1;

  /* Set the size of the (randomly generated) dataset */
  Integer     n = 5000;

  /* Set the maximum number of gaps (0 = no limit) */
  Integer     num_gaps = 0;

  /* Set the length of the maximum gap */
  Integer     max_gap = 10;

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

  printf("nag_gaps_test (g08edc) 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);

  /* Set the length of interval which contains all possible values.
     The data is generated from the range 0.0 to 1.0, so length is 1.0
   */
  length = 1.0;

  /* Set lower and upper limit for the interval used for the gap test */
  lower = 0.4;
  upper = 0.6;

  /* nag_gaps_test (g08edc).
   * Performs the gaps test for randomness
   */
  nag_gaps_test(n, x, num_gaps, max_gap, lower, upper, length, &chi, &df, &p,
                &fail);

  /* Display the results */
  if (fail.code != NE_NOERROR && fail.code != NE_G08ED_GAPS &&
      NE_G08ED_FREQ_LT_ONE)
    {
      printf("Error from nag_gaps_test (g08edc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }
  printf("\n");
  printf("Chisq = %10.4f\n", chi);
  printf("DF    = %7.1f\n", df);
  printf("Prob  = %10.4f\n", p);
  if (fail.code == NE_G08ED_FREQ_LT_ONE)
    printf("Error from nag_gaps_test (g08edc).\n%s\n", fail.message);

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

  return exit_status;
}