/* nag_kernel_density_estim (g10bac) Example Program.
 *
 * Copyright 2000 Numerical Algorithms Group.
 *
 * Mark 6, 2000.
 * Mark 7b revised, 2004.
 */

#include <stdio.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nagg01.h>
#include <nagg05.h>
#include <nagg10.h>

int main(void)
{
  Integer exit_status=0, i, increment, init, *isort=0, j, n, ns;
  NagError fail;
  double enda, endb, high, low, *s=0, *smooth=0, window, *x=0;

  INIT_FAIL(fail);
  Vprintf("nag_kernel_density_estim (g10bac) Example Program Results\n");

  /* Skip heading in data file */
  Vscanf("%*[^\n] ");

  Vscanf("%lf ", &window);
  Vscanf("%lf,  %lf", &low, &high);
  /* Generate Normal (0,1) Distribution */
  n = 1000;
  ns = 100;
  if (!(x = NAG_ALLOC(n, double))
      || !(s = NAG_ALLOC(ns, double))
      || !(smooth = NAG_ALLOC(ns, double))
      || !(isort = NAG_ALLOC(ns, Integer)))
    {
      Vprintf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }

  init = 0;
  /* nag_random_init_repeatable (g05cbc).
   * Initialize random number generating functions to give
   * repeatable sequence
   */
  nag_random_init_repeatable(init);
  enda = 0.0;
  endb = 1.0;
  for (i = 0; i < n; i++)
    /* nag_random_normal (g05ddc).
     * Pseudo-random real numbers, Normal distribution
     */
    x[i] = nag_random_normal(enda, endb);

  /* Perform kernel density estimation */
  /* nag_kernel_density_estim (g10bac).
   * Kernel density estimate using Gaussian kernel
   */
  nag_kernel_density_estim(n, x, window, low, high, ns, smooth, s, &fail);
  if (fail.code != NE_NOERROR)
    {
      Vprintf("Error from nag_kernel_density_estim (g10bac).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

  printf("    Points     Density   Points     Density   Points     "
         "Density   Points     Density\n");
  printf("               Value                Value                "
         "Value                Value\n\n");


  increment = 25;
  for (i=1; i<= ns/4; i++)
    {
      printf("%10.4f %10.4f", s[i-1], smooth[i-1]);
      for (j=1; j <= 3; j++)
        {
          printf("%10.4f %10.4f", s[i-1+j*increment], smooth[i-1+j*increment]);
        }
      printf("\n");
    }
 END:
  if (x) NAG_FREE(x);
  if (s) NAG_FREE(s);
  if (smooth) NAG_FREE(smooth);
  if (isort) NAG_FREE(isort);
  return exit_status;
}