mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-15 09:30:06 +00:00
97 lines
2.6 KiB
C
97 lines
2.6 KiB
C
/* 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"
|
|
|
|
#ifdef __STDC__
|
|
long double jnl(int n, long double x) /* wrapper jnl */
|
|
#else
|
|
long double jnl(n,x) /* wrapper jnl */
|
|
long double x; int n;
|
|
#endif
|
|
{
|
|
#ifdef _IEEE_LIBM
|
|
return __ieee754_jnl(n,x);
|
|
#else
|
|
long double z;
|
|
z = __ieee754_jnl(n,x);
|
|
if(_LIB_VERSION == _IEEE_ || __isnanl(x) ) return z;
|
|
if(fabsl(x)>X_TLOSS) {
|
|
return __kernel_standard((double)n,x,238); /* jn(|x|>X_TLOSS,n) */
|
|
} else
|
|
return z;
|
|
#endif
|
|
}
|
|
|
|
#ifdef __STDC__
|
|
long double ynl(int n, long double x) /* wrapper ynl */
|
|
#else
|
|
long double ynl(n,x) /* wrapper ynl */
|
|
long double x; int n;
|
|
#endif
|
|
{
|
|
#ifdef _IEEE_LIBM
|
|
return __ieee754_ynl(n,x);
|
|
#else
|
|
long double z;
|
|
z = __ieee754_ynl(n,x);
|
|
if(_LIB_VERSION == _IEEE_ || __isnanl(x) ) return z;
|
|
if(x <= 0.0){
|
|
if(x==0.0)
|
|
/* d= -one/(x-x); */
|
|
return __kernel_standard((double)n,x,212);
|
|
else
|
|
/* d = zero/(x-x); */
|
|
return __kernel_standard((double)n,x,213);
|
|
}
|
|
if(x>X_TLOSS) {
|
|
return __kernel_standard((double)n,x,239); /* yn(x>X_TLOSS,n) */
|
|
} else
|
|
return z;
|
|
#endif
|
|
}
|