/* @(#)w_asin.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. * ==================================================== * */ /* FUNCTION <<asin>>, <<asinf>>---arc sine INDEX asin INDEX asinf ANSI_SYNOPSIS #include <math.h> double asin(double <[x]>); float asinf(float <[x]>); TRAD_SYNOPSIS #include <math.h> double asin(<[x]>) double <[x]>; float asinf(<[x]>) float <[x]>; DESCRIPTION <<asin>> computes the inverse sine (arc sine) of the argument <[x]>. Arguments to <<asin>> must be in the range @minus{}1 to 1. <<asinf>> is identical to <<asin>>, other than taking and returning floats. You can modify error handling for these routines using <<matherr>>. RETURNS @ifinfo <<asin>> returns values in radians, in the range of -pi/2 to pi/2. @end ifinfo @tex <<asin>> returns values in radians, in the range of $-\pi/2$ to $\pi/2$. @end tex If <[x]> is not in the range @minus{}1 to 1, <<asin>> and <<asinf>> return NaN (not a number), set the global variable <<errno>> to <<EDOM>>, and issue a <<DOMAIN error>> message. You can change this error treatment using <<matherr>>. QUICKREF ANSI SVID POSIX RENTRANT asin y,y,y,m asinf n,n,n,m MATHREF asin, -1<=arg<=1, asin(arg),,, asin, NAN, arg,EDOM, DOMAIN MATHREF asinf, -1<=arg<=1, asin(arg),,, asinf, NAN, arg,EDOM, DOMAIN */ /* * wrapper asin(x) */ #include "fdlibm.h" #include <errno.h> #ifndef _DOUBLE_IS_32BITS #ifdef __STDC__ double asin(double x) /* wrapper asin */ #else double asin(x) /* wrapper asin */ double x; #endif { #ifdef _IEEE_LIBM return __ieee754_asin(x); #else double z; struct exception exc; z = __ieee754_asin(x); if(_LIB_VERSION == _IEEE_ || isnan(x)) return z; if(fabs(x)>1.0) { /* asin(|x|>1) */ exc.type = DOMAIN; exc.name = "asin"; exc.err = 0; exc.arg1 = exc.arg2 = x; exc.retval = 0.0; if(_LIB_VERSION == _POSIX_) errno = EDOM; else if (!matherr(&exc)) { errno = EDOM; } if (exc.err != 0) errno = exc.err; return exc.retval; } else return z; #endif } #endif /* defined(_DOUBLE_IS_32BITS) */