/* nag_bessel_k_alpha (s18egc) Example Program.
 *
 * Copyright 2000 Numerical Algorithms Group.
 *
 * NAG C Library
 *
 * Mark 6, 2000.
 * Mark 8 revised, 2004.
 */

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

int main(void)
{
  Integer exit_status=0, i, ia, ja, nl;
  NagError fail;
  double alpha, *b=0, x;

  INIT_FAIL(fail);

  /* Skip heading in data file */
  Vscanf("%*[^\n]");
  Vprintf("nag_bessel_k_alpha (s18egc) Example Program Results\n");
  if ( !( b = NAG_ALLOC(101, double)) )
    {
      Vprintf("Allocation failure\n");
      exit_status = -1;
      goto END;
    }

  while (scanf("%lf %ld %ld %ld%*[^\n]", &x, &ia, &ja,
               &nl) != EOF)
    {
      Vprintf("  x      ia     ja     nl\n");
      Vprintf("%4.1f %6ld %6ld %6ld\n\n", x, ia, ja,
              nl);
      /* nag_bessel_k_alpha (s18egc).
       * Modified Bessel functions K_(alpha~+~n)(x) for real
       * x~>~0, selected values of alpha~>=~0 and
       * n~=~0~,~1~,~...~,~N
       */
      nag_bessel_k_alpha(x, ia, ja, nl, b, &fail);
      if (fail.code == NE_NOERROR)
        {
          Vprintf(" Requested values of K_alpha(x)\n\n");
          alpha = (double) ia / (double) ja;
          Vprintf("     alpha      K_alpha(x)\n");
          for (i = 0; i <= nl; ++i)
            {
              Vprintf(" %12.4e %12.4e\n", alpha, b[i]);
              alpha += 1.0;
            }
        }
      else
        {
          Vprintf("Error from nag_bessel_k_alpha (s18egc).\n%s\n",
                  fail.message);
          exit_status = 1;
          goto END;
        }
    }
 END:
  if (b) NAG_FREE(b);
  return exit_status;
}