/* nag_rand_skip_ahead (g05kjc) 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>

int main(void)
{
  /* Integer scalar and array declarations */
  Integer     exit_status = 0;
  Integer     i, lstate;
  Integer     *state = 0;

  /* NAG structures */
  NagError    fail;

  /* Double scalar and array declarations */
  double      *x = 0;

  /* Set the sample size */
  Integer     nv = 5;

  /* Set the number of elements to advance the sequence */
  Integer     n = 50;

  /* 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_skip_ahead (g05kjc) 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;
    }

  /* Allocate arrays */
  if (!(x = NAG_ALLOC(nv, 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;
    }

  /* Advance the sequence N places*/
  nag_rand_skip_ahead(n, state, &fail);
  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_rand_skip_ahead (g05kjc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

  /* Generate a NV variates from a uniform distribution*/
  nag_rand_basic(nv, state, x, &fail);
  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_rand_basic (g05sac).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }

  /* Display the variates*/
  for (i = 0; i < nv; i++)
    printf("%11.4f\n", x[i]);

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

  return exit_status;
}