/* nag_bessel_i_alpha (s18ejc) Example Program.
 *
 * Copyright 2000 Numerical Algorithms Group.
 *
 * NAG C Library
 *
 * Mark 6, 2000.
 */

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

int main(void)
{
  Complex b[101];
  double a;
  double alpha;
  double d;
  double x;
  Integer i;
  Integer exit_status=0;
  Integer nl;
  NagError fail;

  INIT_FAIL(fail);

  /* Skip heading in data file */
  Vscanf("%*[^\n]");
  Vprintf("s18ejc Example Program Results\n");
  while (scanf("%lf %lf %ld%*[^\n]", &x, &a, &nl) != EOF)
    {
      Vprintf("  x     a      nl\n");
      Vprintf("%4.1f  %4.1f %6ld\n\n", x, a, nl);
      s18ejc(x, a, nl, b, &fail);
      if (fail.code == NE_NOERROR)
        {
          Vprintf(" Requested values of I_alpha(X)\n\n");
          alpha = a;
          Vprintf("     alpha              I_alpha(X)\n");
          for (i = 1; i <= ABS(nl) + 1; ++i)
            {
              Vprintf("%12.4e   (%12.4e, %12.4e)\n",
                      alpha, b[i - 1].re, b[i - 1].im);
              d = (double) nl;
              alpha += SIGN(1.0, d);
            }
        }
      else
        {
          Vprintf("Error from s18ejc.\n%s\n", fail.message);
          exit_status = 1;
          goto END;
        }
    }
 END:
  return exit_status;
}                               /* main */