71 lines
2.1 KiB
C
71 lines
2.1 KiB
C
|
/* Complex tangent function for double. */
|
||
|
|
|
||
|
|
/* Copyright (C) 1997-1999 Free Software Foundation, Inc.
|
||
|
|
|
||
|
|
This file is part of the GNU ISO C++ Library. This library is free
|
||
|
|
software; you can redistribute it and/or modify it under the
|
||
|
|
terms of the GNU General Public License as published by the
|
||
|
|
Free Software Foundation; either version 2, or (at your option)
|
||
|
|
any later version.
|
||
|
|
|
||
|
|
This library is distributed in the hope that it will be useful,
|
||
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
GNU General Public License for more details.
|
||
|
|
|
||
|
|
You should have received a copy of the GNU General Public License along
|
||
|
|
with this library; see the file COPYING. If not, write to the Free
|
||
|
|
Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
|
||
|
|
USA.
|
||
|
|
|
||
|
|
As a special exception, you may use this file as part of a free software
|
||
|
|
library without restriction. Specifically, if other files instantiate
|
||
|
|
templates or use macros or inline functions from this file, or you compile
|
||
|
|
this file and link it with other files to produce an executable, this
|
||
|
|
file does not by itself cause the resulting executable to be covered by
|
||
|
|
the GNU General Public License. This exception does not however
|
||
|
|
invalidate any other reasons why the executable file might be covered by
|
||
|
|
the GNU General Public License. */
|
||
|
|
|
||
|
|
|
||
|
|
#include <math.h>
|
||
|
|
#include "mathconf.h"
|
||
|
|
|
||
|
|
|
||
|
|
__complex__ double
|
||
|
|
ctan (__complex__ double x)
|
||
|
|
{
|
||
|
|
__complex__ double res;
|
||
|
|
|
||
|
|
if (!FINITE_P (__real__ x) || !FINITE_P (__imag__ x))
|
||
|
|
{
|
||
|
|
if (INFINITE_P (__imag__ x))
|
||
|
|
{
|
||
|
|
__real__ res = copysign (0.0, __real__ x);
|
||
|
|
__imag__ res = copysign (1.0, __imag__ x);
|
||
|
|
}
|
||
|
|
else if (__real__ x == 0.0)
|
||
|
|
{
|
||
|
|
res = x;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
__real__ res = NAN;
|
||
|
|
__imag__ res = NAN;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
double sin2rx = sin (2.0 * __real__ x);
|
||
|
|
double cos2rx = cos (2.0 * __real__ x);
|
||
|
|
double den;
|
||
|
|
|
||
|
|
den = cos2rx + cosh (2.0 * __imag__ x);
|
||
|
|
|
||
|
|
__real__ res = sin2rx / den;
|
||
|
|
__imag__ res = sinh (2.0 * __imag__ x) / den;
|
||
|
|
}
|
||
|
|
|
||
|
|
return res;
|
||
|
|
}
|