/* nag_prob_students_t (g01ebc) Example Program.
 *
 * Copyright 1996 Numerical Algorithms Group.
 *
 * Mark 4, 1996.
 * Mark 5 revised, 1998.
 * Mark 7 revised, 2001.
 *
 */

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

int main(int argc, char *argv[])
{
  FILE                       *fpin, *fpout;
  Integer                    exit_status = 0;
  double                     df, prob, t;
  int                        i;
  static Nag_TailProbability tail[4] = { Nag_LowerTail, Nag_UpperTail,
                                         Nag_TwoTailSignif, Nag_TwoTailConfid };
  static const char          *tailmess[] = { "Nag_LowerTail", "Nag_UpperTail",
                                             "Nag_TwoTailSignif",
                                             "Nag_TwoTailConfid" };
  NagError                   fail;

  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_prob_students_t (g01ebc) Example Program Results\n\n");
  /* Skip heading in data file */
  fscanf(fpin, "%*[^\n]");
  fprintf(fpout, "    t      df     prob      tail\n\n");
  while (fscanf(fpin, "%lf %lf %d\n", &t, &df, &i) != EOF)
    {
      /* nag_prob_students_t (g01ebc).
       * Probabilities for Student's t-distribution
       */
      prob = nag_prob_students_t(tail[i], t, df, &fail);
      if (fail.code != NE_NOERROR)
        {
          fprintf(fpout, "Error from nag_prob_students_t (g01ebc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }
      fprintf(fpout, " %6.3f%8.3f%8.4f  %s\n", t, df, prob, tailmess[i]);
    }

 END:
  if (fpin != stdin) fclose(fpin);
  if (fpout != stdout) fclose(fpout);
  return exit_status;
}