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| 2 | /* @(#)w_asin.c 5.1 93/09/24 */
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| 3 | /*
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| 4 | * ====================================================
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| 5 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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| 6 | *
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| 7 | * Developed at SunPro, a Sun Microsystems, Inc. business.
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| 8 | * Permission to use, copy, modify, and distribute this
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| 9 | * software is freely granted, provided that this notice
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| 10 | * is preserved.
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| 11 | * ====================================================
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| 12 | *
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| 13 | */
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| 14 |
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| 15 | /*
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| 16 | FUNCTION
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| 17 | <<asin>>, <<asinf>>---arc sine
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| 18 |
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| 19 | INDEX
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| 20 | asin
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| 21 | INDEX
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| 22 | asinf
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| 23 |
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| 24 | ANSI_SYNOPSIS
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| 25 | #include <math.h>
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| 26 | double asin(double <[x]>);
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| 27 | float asinf(float <[x]>);
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| 28 |
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| 29 | TRAD_SYNOPSIS
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| 30 | #include <math.h>
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| 31 | double asin(<[x]>)
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| 32 | double <[x]>;
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| 33 |
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| 34 | float asinf(<[x]>)
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| 35 | float <[x]>;
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| 36 |
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| 37 |
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| 38 | DESCRIPTION
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| 39 |
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| 40 | <<asin>> computes the inverse sine (arc sine) of the argument <[x]>.
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| 41 | Arguments to <<asin>> must be in the range @minus{}1 to 1.
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| 42 |
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| 43 | <<asinf>> is identical to <<asin>>, other than taking and
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| 44 | returning floats.
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| 45 |
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| 46 | You can modify error handling for these routines using <<matherr>>.
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| 47 |
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| 48 | RETURNS
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| 49 | @ifinfo
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| 50 | <<asin>> returns values in radians, in the range of -pi/2 to pi/2.
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| 51 | @end ifinfo
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| 52 | @tex
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| 53 | <<asin>> returns values in radians, in the range of $-\pi/2$ to $\pi/2$.
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| 54 | @end tex
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| 55 |
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| 56 | If <[x]> is not in the range @minus{}1 to 1, <<asin>> and <<asinf>>
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| 57 | return NaN (not a number), set the global variable <<errno>> to
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| 58 | <<EDOM>>, and issue a <<DOMAIN error>> message.
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| 59 |
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| 60 | You can change this error treatment using <<matherr>>.
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| 61 |
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| 62 | QUICKREF ANSI SVID POSIX RENTRANT
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| 63 | asin y,y,y,m
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| 64 | asinf n,n,n,m
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| 65 |
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| 66 | MATHREF
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| 67 | asin, -1<=arg<=1, asin(arg),,,
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| 68 | asin, NAN, arg,EDOM, DOMAIN
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| 69 |
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| 70 | MATHREF
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| 71 | asinf, -1<=arg<=1, asin(arg),,,
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| 72 | asinf, NAN, arg,EDOM, DOMAIN
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| 73 |
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| 74 |
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| 75 | */
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| 76 |
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| 77 | /*
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| 78 | * wrapper asin(x)
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| 79 | */
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| 80 |
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| 81 |
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| 82 | #include "fdlibm.h"
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| 83 | #include <errno.h>
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| 84 |
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| 85 | #ifndef _DOUBLE_IS_32BITS
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| 86 |
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| 87 | #ifdef __STDC__
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| 88 | double asin(double x) /* wrapper asin */
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| 89 | #else
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| 90 | double asin(x) /* wrapper asin */
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| 91 | double x;
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| 92 | #endif
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| 93 | {
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| 94 | #ifdef _IEEE_LIBM
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| 95 | return __ieee754_asin(x);
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| 96 | #else
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| 97 | double z;
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| 98 | struct exception exc;
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| 99 | z = __ieee754_asin(x);
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| 100 | if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
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| 101 | if(fabs(x)>1.0) {
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| 102 | /* asin(|x|>1) */
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| 103 | exc.type = DOMAIN;
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| 104 | exc.name = "asin";
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| 105 | exc.err = 0;
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| 106 | exc.arg1 = exc.arg2 = x;
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| 107 | exc.retval = 0.0;
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| 108 | if(_LIB_VERSION == _POSIX_)
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| 109 | errno = EDOM;
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| 110 | else if (!matherr(&exc)) {
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| 111 | errno = EDOM;
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| 112 | }
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| 113 | if (exc.err != 0)
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| 114 | errno = exc.err;
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| 115 | return exc.retval;
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| 116 | } else
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| 117 | return z;
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| 118 | #endif
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| 119 | }
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| 120 |
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| 121 | #endif /* defined(_DOUBLE_IS_32BITS) */
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