0,0 → 1,121 |
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/* @(#)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 |
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ANSI_SYNOPSIS |
#include <math.h> |
double asin(double <[x]>); |
float asinf(float <[x]>); |
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TRAD_SYNOPSIS |
#include <math.h> |
double asin(<[x]>) |
double <[x]>; |
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float asinf(<[x]>) |
float <[x]>; |
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DESCRIPTION |
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<<asin>> computes the inverse sine (arc sine) of the argument <[x]>. |
Arguments to <<asin>> must be in the range @minus{}1 to 1. |
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<<asinf>> is identical to <<asin>>, other than taking and |
returning floats. |
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You can modify error handling for these routines using <<matherr>>. |
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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 |
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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. |
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You can change this error treatment using <<matherr>>. |
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QUICKREF ANSI SVID POSIX RENTRANT |
asin y,y,y,m |
asinf n,n,n,m |
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MATHREF |
asin, -1<=arg<=1, asin(arg),,, |
asin, NAN, arg,EDOM, DOMAIN |
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MATHREF |
asinf, -1<=arg<=1, asin(arg),,, |
asinf, NAN, arg,EDOM, DOMAIN |
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*/ |
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/* |
* wrapper asin(x) |
*/ |
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#include "fdlibm.h" |
#include <errno.h> |
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#ifndef _DOUBLE_IS_32BITS |
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#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 = nan(""); |
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 |
} |
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#endif /* defined(_DOUBLE_IS_32BITS) */ |