/* nag_shapiro_wilk_test (g01ddc) Example Program.
 *
 * Copyright 1996 Numerical Algorithms Group.
 *
 * Mark 4, 1996.
 * Mark 8 revised, 2004.
 *
 */

#include <nag.h>
#include <nagx04.h>
#include <nag_stdlib.h>
#include <stdio.h>
#include <nagg01.h>
#include <nagm01.h>

int main(int argc, char *argv[])
{
  FILE        *fpin, *fpout;

  /* Local variables */
  Nag_Boolean calwts;
  Integer     exit_status = 0, i, j, n;
  NagError    fail;
  double      *a = 0, pw, w, *x = 0;

  INIT_FAIL(fail);

  /* Check for command-line IO options */
  fpin = nag_example_file_io(argc, argv, "-data", NULL);
  fpout = nag_example_file_io(argc, argv, "-results", NULL);
  fprintf(fpout, "nag_shapiro_wilk_test (g01ddc) Example Program Results\n");

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

  calwts = Nag_TRUE;
  fscanf(fpin, "%ld ", &n);
  if (n >= 3)
    {
      if (!(a = NAG_ALLOC(n, double)) ||
          !(x = NAG_ALLOC(n, double)))
        {
          fprintf(fpout, "Allocation failure\n");
          exit_status = -1;
          goto END;
        }
    }
  else
    {
      fprintf(fpout, "Invalid n.\n");
      exit_status = 1;
      return exit_status;
    }
  for (j = 1; j <= 2; ++j)
    {
      for (i = 1; i <= n; ++i)
        fscanf(fpin, "%lf ", &x[i - 1]);

      /* nag_double_sort (m01cac).
       * Quicksort of set of values of data type double
       */
      nag_double_sort(x, (size_t) n, Nag_Ascending, &fail);
      if (fail.code != NE_NOERROR)
        {
          fprintf(fpout, "Error from nag_double_sort (m01cac).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }
      /* nag_shapiro_wilk_test (g01ddc).
       * Shapiro and Wilk's W test for Normality
       */
      nag_shapiro_wilk_test(n, x, calwts, a, &w, &pw, &fail);
      if (fail.code != NE_NOERROR)
        {
          fprintf(fpout, "Error from nag_shapiro_wilk_test (g01ddc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }


      fprintf(fpout, "\n For sample number %2ld, value of W statistic = "
              "%7.4f\n", j, w);
      fprintf(fpout, "                       Significance level is %8.4f\n",
              pw);
      calwts = Nag_FALSE;
    }
 END:
  if (fpin != stdin) fclose(fpin);
  if (fpout != stdout) fclose(fpout);
  if (a) NAG_FREE(a);
  if (x) NAG_FREE(x);
  return exit_status;
}