122 lines
2.4 KiB
C
122 lines
2.4 KiB
C
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/* @(#)w_asin.c 5.1 93/09/24 */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*
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*/
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/*
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FUNCTION
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<<asin>>, <<asinf>>---arc sine
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INDEX
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asin
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INDEX
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asinf
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ANSI_SYNOPSIS
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#include <math.h>
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double asin(double <[x]>);
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float asinf(float <[x]>);
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TRAD_SYNOPSIS
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#include <math.h>
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double asin(<[x]>)
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double <[x]>;
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float asinf(<[x]>)
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float <[x]>;
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DESCRIPTION
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<<asin>> computes the inverse sine (arc sine) of the argument <[x]>.
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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
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returning floats.
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You can modify error handling for these routines using <<matherr>>.
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RETURNS
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@ifinfo
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<<asin>> returns values in radians, in the range of -pi/2 to pi/2.
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@end ifinfo
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@tex
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<<asin>> returns values in radians, in the range of $-\pi/2$ to $\pi/2$.
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@end tex
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If <[x]> is not in the range @minus{}1 to 1, <<asin>> and <<asinf>>
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return NaN (not a number), set the global variable <<errno>> to
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<<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
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asin y,y,y,m
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asinf n,n,n,m
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MATHREF
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asin, -1<=arg<=1, asin(arg),,,
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asin, NAN, arg,EDOM, DOMAIN
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MATHREF
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asinf, -1<=arg<=1, asin(arg),,,
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asinf, NAN, arg,EDOM, DOMAIN
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*/
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/*
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* wrapper asin(x)
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*/
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#include "fdlibm.h"
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#include <errno.h>
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#ifndef _DOUBLE_IS_32BITS
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#ifdef __STDC__
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double asin(double x) /* wrapper asin */
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#else
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double asin(x) /* wrapper asin */
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double x;
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#endif
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{
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#ifdef _IEEE_LIBM
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return __ieee754_asin(x);
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#else
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double z;
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struct exception exc;
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z = __ieee754_asin(x);
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if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
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if(fabs(x)>1.0) {
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/* asin(|x|>1) */
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exc.type = DOMAIN;
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exc.name = "asin";
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exc.err = 0;
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exc.arg1 = exc.arg2 = x;
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exc.retval = 0.0;
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if(_LIB_VERSION == _POSIX_)
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errno = EDOM;
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else if (!matherr(&exc)) {
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errno = EDOM;
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}
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if (exc.err != 0)
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errno = exc.err;
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return exc.retval;
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} else
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return z;
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#endif
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}
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#endif /* defined(_DOUBLE_IS_32BITS) */
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