## File: w_jnl.c

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glibc 2.19-13
 `12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788899091` ``````/* 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 nx, 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 #include long double __jnl(int n, long double x) /* wrapper jnl */ { #ifdef _IEEE_LIBM return __ieee754_jnl(n,x); #else long double z; z = __ieee754_jnl(n,x); if (_LIB_VERSION == _IEEE_ || _LIB_VERSION == _POSIX_ || __isnanl(x)) return z; if(fabsl(x)>X_TLOSS) { return __kernel_standard_l((double)n,x,238); /* jn(|x|>X_TLOSS,n) */ } else return z; #endif } weak_alias (__jnl, jnl) long double __ynl(int n, long double x) /* wrapper ynl */ { #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_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; #endif } weak_alias (__ynl, ynl) ``````