94 lines
3.1 KiB
C
94 lines
3.1 KiB
C
/* $NetBSD: cacosh.c,v 1.2 2009/08/03 19:41:32 drochner Exp $ */
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/*-
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* Copyright (c) 2007 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software written by Stephen L. Moshier.
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* It is redistributed by the NetBSD Foundation by permission of the author.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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* imported and modified include for newlib 2010/10/03
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* Marco Atzeri <marco_atzeri@yahoo.it>
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*/
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/*
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FUNCTION
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<<cacosh>>, <<cacoshf>>---complex arc hyperbolic cosine
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INDEX
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cacosh
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INDEX
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cacoshf
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SYNOPSIS
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#include <complex.h>
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double complex cacosh(double complex <[z]>);
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float complex cacoshf(float complex <[z]>);
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DESCRIPTION
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These functions compute the complex arc hyperbolic cosine of <[z]>,
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with a branch cut at values less than 1 along the real axis.
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<<cacoshf>> is identical to <<cacosh>>, except that it performs
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its calculations on <<floats complex>>.
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RETURNS
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@ifnottex
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These functions return the complex arc hyperbolic cosine value,
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in the range of a half-strip of non-negative values along the
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real axis and in the interval [-i * pi, +i * pi] along the
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imaginary axis.
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@end ifnottex
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@tex
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These functions return the complex arc hyperbolic cosine value,
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in the range of a half-strip of non-negative values along the
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real axis and in the interval [$-i\pi$, $+i\pi$] along the
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imaginary axis.
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@end tex
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PORTABILITY
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<<cacosh>> and <<cacoshf>> are ISO C99
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QUICKREF
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<<cacosh>> and <<cacoshf>> are ISO C99
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*/
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#include <complex.h>
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double complex
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cacosh(double complex z)
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{
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double complex w;
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#if 0 /* does not give the principal value */
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w = I * cacos(z);
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#else
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w = clog(z + csqrt(z + 1) * csqrt(z - 1));
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#endif
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return w;
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}
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