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/* $NetBSD: ctan.c,v 1.1 2007/08/20 16:01:37 drochner Exp $ */
/*-
* Copyright (c) 2007 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software written by Stephen L. Moshier.
* It is redistributed by the NetBSD Foundation by permission of the author.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* imported and modified include for newlib 2010/10/03
* Marco Atzeri <marco_atzeri@yahoo.it>
*/
/*
FUNCTION
<<ctan>>, <<ctanf>>---complex tangent
INDEX
ctan
INDEX
ctanf
SYNOPSIS
#include <complex.h>
double complex ctan(double complex <[z]>);
float complex ctanf(float complex <[z]>);
DESCRIPTION
These functions compute the complex tangent of <[z]>.
<<ctanf>> is identical to <<ctan>>, except that it performs
its calculations on <<floats complex>>.
RETURNS
These functions return the complex tangent value.
PORTABILITY
<<ctan>> and <<ctanf>> are ISO C99
QUICKREF
<<ctan>> and <<ctanf>> are ISO C99
*/
#include <complex.h>
#include <math.h>
#include "cephes_subr.h"
double complex
ctan(double complex z)
{
double complex w;
double d;
d = cos(2.0 * creal(z)) + cosh(2.0 * cimag(z));
if (fabs(d) < 0.25)
d = _ctans(z);
if (d == 0.0) {
/* mtherr ("ctan", OVERFLOW); */
w = HUGE_VAL + HUGE_VAL * (double complex) I;
return w;
}
w = sin(2.0 * creal(z)) / d + (sinh(2.0 * cimag(z)) / d) * (double complex) I;
return w;
}
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