| |
| /* @(#)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) */ |