/* nag_bessel_k_nu (s18efc) Example Program.
 *
 * Copyright 2000 Numerical Algorithms Group.
 *
 * NAG C Library
 *
 * Mark 6, 2000.
 */

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

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

  Integer  exit_status = 0, nu;
  NagError fail;
  double   x, y;

  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_bessel_k_nu (s18efc) Example Program Results\n");
  fprintf(fpout, "  x      nu        y\n");
  while (fscanf(fpin, "%lf %ld%*[^\n]", &x, &nu) != EOF)
    {
      /* nag_bessel_k_nu (s18efc).
       * Modified Bessel function K_(nu~/~4)(x)
       */
      y = nag_bessel_k_nu(x, nu, &fail);
      if (fail.code != NE_NOERROR)
        {
          fprintf(fpout, "Error from nag_bessel_k_nu (s18efc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }
      fprintf(fpout, "%4.1f %6ld %13.4e\n", x, nu, y);
    }
 END:
  if (fpin != stdin) fclose(fpin);
  if (fpout != stdout) fclose(fpout);
  return exit_status;
}