mirror of
https://github.com/autc04/Retro68.git
synced 2024-11-24 07:31:32 +00:00
142 lines
3.4 KiB
C
142 lines
3.4 KiB
C
|
|
/* @(#)w_jn.c 5.1 93/09/24 */
|
|
/*
|
|
* ====================================================
|
|
* 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.
|
|
* ====================================================
|
|
*/
|
|
|
|
/*
|
|
* 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 "fdlibm.h"
|
|
#include <errno.h>
|
|
|
|
#ifndef _DOUBLE_IS_32BITS
|
|
|
|
#ifdef __STDC__
|
|
double jn(int n, double x) /* wrapper jn */
|
|
#else
|
|
double jn(n,x) /* wrapper jn */
|
|
double x; int n;
|
|
#endif
|
|
{
|
|
#ifdef _IEEE_LIBM
|
|
return __ieee754_jn(n,x);
|
|
#else
|
|
double z;
|
|
struct exception exc;
|
|
z = __ieee754_jn(n,x);
|
|
if(_LIB_VERSION == _IEEE_ || isnan(x) ) return z;
|
|
if(fabs(x)>X_TLOSS) {
|
|
/* jn(|x|>X_TLOSS) */
|
|
exc.type = TLOSS;
|
|
exc.name = "jn";
|
|
exc.err = 0;
|
|
exc.arg1 = n;
|
|
exc.arg2 = x;
|
|
exc.retval = 0.0;
|
|
if (_LIB_VERSION == _POSIX_)
|
|
errno = ERANGE;
|
|
else if (!matherr(&exc)) {
|
|
errno = ERANGE;
|
|
}
|
|
if (exc.err != 0)
|
|
errno = exc.err;
|
|
return exc.retval;
|
|
} else
|
|
return z;
|
|
#endif
|
|
}
|
|
|
|
#ifdef __STDC__
|
|
double yn(int n, double x) /* wrapper yn */
|
|
#else
|
|
double yn(n,x) /* wrapper yn */
|
|
double x; int n;
|
|
#endif
|
|
{
|
|
#ifdef _IEEE_LIBM
|
|
return __ieee754_yn(n,x);
|
|
#else
|
|
double z;
|
|
struct exception exc;
|
|
z = __ieee754_yn(n,x);
|
|
if(_LIB_VERSION == _IEEE_ || isnan(x) ) return z;
|
|
if(x <= 0.0){
|
|
/* yn(n,0) = -inf or yn(x<0) = NaN */
|
|
#ifndef HUGE_VAL
|
|
#define HUGE_VAL inf
|
|
double inf = 0.0;
|
|
|
|
SET_HIGH_WORD(inf,0x7ff00000); /* set inf to infinite */
|
|
#endif
|
|
exc.type = DOMAIN; /* should be SING for IEEE */
|
|
exc.name = "yn";
|
|
exc.err = 0;
|
|
exc.arg1 = n;
|
|
exc.arg2 = x;
|
|
if (_LIB_VERSION == _SVID_)
|
|
exc.retval = -HUGE;
|
|
else
|
|
exc.retval = -HUGE_VAL;
|
|
if (_LIB_VERSION == _POSIX_)
|
|
errno = EDOM;
|
|
else if (!matherr(&exc)) {
|
|
errno = EDOM;
|
|
}
|
|
if (exc.err != 0)
|
|
errno = exc.err;
|
|
return exc.retval;
|
|
}
|
|
if(x>X_TLOSS) {
|
|
/* yn(x>X_TLOSS) */
|
|
exc.type = TLOSS;
|
|
exc.name = "yn";
|
|
exc.err = 0;
|
|
exc.arg1 = n;
|
|
exc.arg2 = x;
|
|
exc.retval = 0.0;
|
|
if (_LIB_VERSION == _POSIX_)
|
|
errno = ERANGE;
|
|
else if (!matherr(&exc)) {
|
|
errno = ERANGE;
|
|
}
|
|
if (exc.err != 0)
|
|
errno = exc.err;
|
|
return exc.retval;
|
|
} else
|
|
return z;
|
|
#endif
|
|
}
|
|
|
|
#endif /* defined(_DOUBLE_IS_32BITS) */
|