/* nag_polygamma_fun (s14acc) Example Program.
 *
 * Copyright 2002 Numerical Algorithms Group.
 *
 * Mark 7, 2002.
 */

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

int main(int argc, char *argv[])
{
  FILE     *fpin, *fpout;
  Integer  exit_status = 0;
  double   f, x;
  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);

  /* Skip heading in data file */
  fscanf(fpin, "%*[^\n]");
  fprintf(fpout, "nag_polygamma_fun (s14acc) Example Program Results\n");
  fprintf(fpout, "     x       psi(x)-log(x)\n");
  while (fscanf(fpin, "%lf", &x) != EOF)
    {
      /* nag_polygamma_fun (s14acc).
       * psi(x)~-~ln~x
       */
      f = nag_polygamma_fun(x, &fail);
      if (fail.code != NE_NOERROR)
        {
          fprintf(fpout, "Error from nag_polygamma_fun (s14acc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }
      fprintf(fpout, "%8.3f %14.4f\n", x, f);
    }

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