1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
|
/* w_jnl.c -- long double version of w_jn.c.
* Conversion to long double by Ulrich Drepper,
* Cygnus Support, drepper@cygnus.com.
*/
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: $";
#endif
/*
* wrapper jn(int n, double x), yn(int n, double x)
* floating point Bessel's function of the 1st and 2nd kind
* of order n
*
* Special cases:
* y0(0)=y1(0)=yn(n,0) = -inf with division by zero signal;
* y0(-ve)=y1(-ve)=yn(n,-ve) are NaN with invalid signal.
* Note 2. About jn(n,x), yn(n,x)
* For n=0, j0(x) is called,
* for n=1, j1(x) is called,
* for n<x, forward recursion us used starting
* from values of j0(x) and j1(x).
* for n>x, a continued fraction approximation to
* j(n,x)/j(n-1,x) is evaluated and then backward
* recursion is used starting from a supposed value
* for j(n,x). The resulting value of j(0,x) is
* compared with the actual value to correct the
* supposed value of j(n,x).
*
* yn(n,x) is similar in all respects, except
* that forward recursion is used for all
* values of n>1.
*
*/
#include <math.h>
#include "math_private.h"
#if !defined __NO_LONG_DOUBLE_MATH
# ifndef __DO_XSI_MATH__
long double
jnl(int n, long double x) /* wrapper jnl */
{
# if __UCLIBC_HAS_FENV__
long double z;
z = (long double) __ieee754_jn(n, (double) x);
if (_LIB_VERSION == _IEEE_
|| _LIB_VERSION == _POSIX_
|| isnan(x))
return z;
if(fabsl(x)>X_TLOSS) {
return __kernel_standard_l((double)n,x,238); /* jn(|x|>X_TLOSS,n) */
} else
return z;
# else
return (long double) __ieee754_jn(n, (double) x);
# endif /* __UCLIBC_HAS_FENV__ */
}
long double
ynl(int n, long double x) /* wrapper ynl */
{
# if __UCLIBC_HAS_FENV__
long double z;
z = (long double) __ieee754_yn(n,(double) x);
if(_LIB_VERSION == _IEEE_ || isnan(x) ) return z;
if(x <= 0.0){
if(x==0.0)
/* d= -one/(x-x); */
return __kernel_standard_l((double)n,x,212);
else
/* d = zero/(x-x); */
return __kernel_standard_l((double)n,x,213);
}
if(x>X_TLOSS && _LIB_VERSION != _POSIX_) {
return __kernel_standard_l((double)n,x,239); /* yn(x>X_TLOSS,n) */
} else
return z;
# else
return (long double) __ieee754_yn(n,(double) x);
# endif /* __UCLIBC_HAS_FENV__ */
}
# endif /* __DO_XSI_MATH__ */
#endif /* __NO_LONG_DOUBLE_MATH */
|
