/* nag_complex_bessel_j_seq (s18gkc) 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;
  Complex  z, b[20];
  double   a, alpha;
  Integer  i, nl;
  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_complex_bessel_j_seq (s18gkc) Example Program Results\n");
  while (fscanf(fpin, " (%lf,%lf) %lf %ld%*[^\n] ", &z.re, &z.im, &a,
                &nl) != EOF)
    {
      /* nag_complex_bessel_j_seq (s18gkc).
       * Bessel function of the 1st kind J_(alpha~+/-~n)(z)
       */
      nag_complex_bessel_j_seq(z, a, nl, b, &fail);
      if (fail.code == NE_NOERROR)
        {
          fprintf(fpout, "         z             a       nl\n");
          fprintf(fpout, " (%7.3f,%7.3f)  %lf    %ld\n\n", z.re, z.im, a, nl);
          fprintf(fpout, "Requested values of J_alpha(Z)\n\n");
          alpha = a;
          fprintf(fpout, "     alpha              J_alpha(z)\n");
          for (i = 0; i < ABS(nl) + 1; i++)
            {
              fprintf(fpout, "%13.4e   (%13.4e,%13.4e)\n", alpha, b[i].re,
                      b[i].im);
              if (nl > 0)
                alpha += 1.0;
              else
                alpha -= 1.0;
            }
        }
      else
        {
          fprintf(fpout, "Error from nag_complex_bessel_j_seq (s18gkc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }
    }

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

  return exit_status;
}