122 lines
2.4 KiB
C
122 lines
2.4 KiB
C
|
|
/* @(#)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
|
|
@ifnottex
|
|
<<asin>> returns values in radians, in the range of -pi/2 to pi/2.
|
|
@end ifnottex
|
|
@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) */
|