/* nag_durbin_watson_stat (g02fcc) Example Program.
 *
 * Copyright 2002 Numerical Algorithms Group.
 *
 * Mark 7, 2002.
 */

#include <stdio.h>
#include <nag.h>
#include <nagx04.h>
#include <nag_stdlib.h>
#include <nagg02.h>

int main(int argc, char *argv[])
{
  FILE     *fpin, *fpout;
  /* Scalars */
  double   d, pdl, pdu;
  Integer  exit_status, i, p, n;
  NagError fail;

  /* Arrays */
  double   *res = 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);
  exit_status = 0;
  fprintf(fpout, "nag_durbin_watson_stat (g02fcc) Example Program Results\n");

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

  fscanf(fpin, "%ld%*[^\n] ", &p);
  n = 10;

  /* Allocate memory */
  if (!(res = NAG_ALLOC(n, double)))
    {
      fprintf(fpout, "Allocation failure\n");
      exit_status = -1;
      goto END;
    }

  for (i = 1; i <= n; ++i)
    fscanf(fpin, "%lf", &res[i - 1]);
  fscanf(fpin, "%*[^\n] ");

  /* nag_durbin_watson_stat (g02fcc).
   * Computes Durbin-Watson test statistic
   */
  nag_durbin_watson_stat(n, p, res, &d, &pdl, &pdu, &fail);
  if (fail.code != NE_NOERROR)
    {
      fprintf(fpout, "Error from nag_durbin_watson_stat (g02fcc).\n%s\n",
              fail.message);
      exit_status = 1;
      goto END;
    }

  fprintf(fpout, "\n");
  fprintf(fpout, " Durbin-Watson statistic %10.4f\n\n", d);
  fprintf(fpout, " Lower and upper bound %10.4f%10.4f\n", pdl, pdu);
 END:
  if (fpin != stdin) fclose(fpin);
  if (fpout != stdout) fclose(fpout);
  if (res) NAG_FREE(res);
  return exit_status;
}