/* nag_bessel_k_alpha (s18egc) Example Program.
 *
 * Copyright 2017 Numerical Algorithms Group.
 *
 * NAG C Library
 *
 * Mark 26.2, 2017.
 */

#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 */
  scanf("%*[^\n]");
  printf("nag_bessel_k_alpha (s18egc) Example Program Results\n");
  if (!(b = NAG_ALLOC(101, double)))
  {
    printf("Allocation failure\n");
    exit_status = -1;
    goto END;
  }
  while (scanf
         ("%lf %" NAG_IFMT " %" NAG_IFMT " %" NAG_IFMT "%*[^\n]", &x, &ia,
          &ja, &nl) != EOF) {
    printf("  x      ia     ja     nl\n");
    printf("%4.1f %6" NAG_IFMT " %6" NAG_IFMT " %6" NAG_IFMT "\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) {
      printf("Error from nag_bessel_k_alpha (s18egc).\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }
    printf(" Requested values of K_alpha(x)\n\n");
    alpha = (double) ia / (double) ja;
    printf("     alpha        K_alpha(x)\n");
    for (i = 0; i <= nl; ++i) {
      printf(" %13.4e %13.4e\n", alpha, b[i]);
      alpha += 1.0;
    }
  }

END:
  NAG_FREE(b);
  return exit_status;
}