112 lines
2.5 KiB
C
112 lines
2.5 KiB
C
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/* @(#)w_hypot.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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FUNCTION
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<<hypot>>, <<hypotf>>---distance from origin
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INDEX
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hypot
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INDEX
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hypotf
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ANSI_SYNOPSIS
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#include <math.h>
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double hypot(double <[x]>, double <[y]>);
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float hypotf(float <[x]>, float <[y]>);
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TRAD_SYNOPSIS
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double hypot(<[x]>, <[y]>)
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double <[x]>, <[y]>;
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float hypotf(<[x]>, <[y]>)
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float <[x]>, <[y]>;
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DESCRIPTION
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<<hypot>> calculates the Euclidean distance
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@tex
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$\sqrt{x^2+y^2}$
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@end tex
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@ifnottex
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<<sqrt(<[x]>*<[x]> + <[y]>*<[y]>)>>
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@end ifnottex
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between the origin (0,0) and a point represented by the
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Cartesian coordinates (<[x]>,<[y]>). <<hypotf>> differs only
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in the type of its arguments and result.
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RETURNS
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Normally, the distance value is returned. On overflow,
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<<hypot>> returns <<HUGE_VAL>> and sets <<errno>> to
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<<ERANGE>>.
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You can change the error treatment with <<matherr>>.
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PORTABILITY
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<<hypot>> and <<hypotf>> are not ANSI C. */
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/*
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* wrapper hypot(x,y)
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*/
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#define _IEEE_LIBM
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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 hypot(double x, double y)/* wrapper hypot */
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#else
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double hypot(x,y) /* wrapper hypot */
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double x,y;
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#endif
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{
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#ifdef _IEEE_LIBM
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return __ieee754_hypot(x,y);
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#else
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double z;
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struct exception exc;
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z = __ieee754_hypot(x,y);
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if(_LIB_VERSION == _IEEE_) return z;
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if((!finite(z))&&finite(x)&&finite(y)) {
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/* hypot(finite,finite) overflow */
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#ifndef HUGE_VAL
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#define HUGE_VAL inf
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double inf = 0.0;
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SET_HIGH_WORD(inf,0x7ff00000); /* set inf to infinite */
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#endif
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exc.type = OVERFLOW;
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exc.name = "hypot";
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exc.err = 0;
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exc.arg1 = x;
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exc.arg2 = y;
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if (_LIB_VERSION == _SVID_)
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exc.retval = HUGE;
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else
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exc.retval = HUGE_VAL;
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if (_LIB_VERSION == _POSIX_)
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errno = ERANGE;
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else if (!matherr(&exc)) {
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errno = ERANGE;
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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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