1/* w_jnl.c -- long double version of w_jn.c.
2 * Conversion to long double by Ulrich Drepper,
3 * Cygnus Support, drepper@cygnus.com.
4 */
5
6/*
7 * ====================================================
8 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
9 *
10 * Developed at SunPro, a Sun Microsystems, Inc. business.
11 * Permission to use, copy, modify, and distribute this
12 * software is freely granted, provided that this notice
13 * is preserved.
14 * ====================================================
15 */
16
17#if defined(LIBM_SCCS) && !defined(lint)
18static char rcsid[] = "$NetBSD: $";
19#endif
20
21/*
22 * wrapper jn(int n, double x), yn(int n, double x)
23 * floating point Bessel's function of the 1st and 2nd kind
24 * of order n
25 *
26 * Special cases:
27 *	y0(0)=y1(0)=yn(n,0) = -inf with division by zero signal;
28 *	y0(-ve)=y1(-ve)=yn(n,-ve) are NaN with invalid signal.
29 * Note 2. About jn(n,x), yn(n,x)
30 *	For n=0, j0(x) is called,
31 *	for n=1, j1(x) is called,
32 *	for n<x, forward recursion us used starting
33 *	from values of j0(x) and j1(x).
34 *	for n>x, a continued fraction approximation to
35 *	j(n,x)/j(n-1,x) is evaluated and then backward
36 *	recursion is used starting from a supposed value
37 *	for j(n,x). The resulting value of j(0,x) is
38 *	compared with the actual value to correct the
39 *	supposed value of j(n,x).
40 *
41 *	yn(n,x) is similar in all respects, except
42 *	that forward recursion is used for all
43 *	values of n>1.
44 *
45 */
46
47#include "math.h"
48#include "math_private.h"
49
50#ifdef __STDC__
51	long double jnl(int n, long double x)	/* wrapper jnl */
52#else
53	long double jnl(n,x)			/* wrapper jnl */
54	long double x; int n;
55#endif
56{
57#ifdef _IEEE_LIBM
58	return __ieee754_jnl(n,x);
59#else
60	long double z;
61	z = __ieee754_jnl(n,x);
62	if(_LIB_VERSION == _IEEE_ || __isnanl(x) ) return z;
63	if(fabsl(x)>X_TLOSS) {
64	    return __kernel_standard((double)n,x,238); /* jn(|x|>X_TLOSS,n) */
65	} else
66	    return z;
67#endif
68}
69
70#ifdef __STDC__
71	long double ynl(int n, long double x)	/* wrapper ynl */
72#else
73	long double ynl(n,x)			/* wrapper ynl */
74	long double x; int n;
75#endif
76{
77#ifdef _IEEE_LIBM
78	return __ieee754_ynl(n,x);
79#else
80	long double z;
81	z = __ieee754_ynl(n,x);
82	if(_LIB_VERSION == _IEEE_ || __isnanl(x) ) return z;
83        if(x <= 0.0){
84                if(x==0.0)
85                    /* d= -one/(x-x); */
86                    return __kernel_standard((double)n,x,212);
87                else
88                    /* d = zero/(x-x); */
89                    return __kernel_standard((double)n,x,213);
90        }
91	if(x>X_TLOSS) {
92	    return __kernel_standard((double)n,x,239); /* yn(x>X_TLOSS,n) */
93	} else
94	    return z;
95#endif
96}
97