82 lines
2.3 KiB
C
82 lines
2.3 KiB
C
|
/* $NetBSD: catan.c,v 1.1 2007/08/20 16:01:32 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>
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <complex.h>
|
||
|
|
#include <math.h>
|
||
|
|
#include "cephes_subr.h"
|
||
|
|
|
||
|
|
#ifdef __weak_alias
|
||
|
|
__weak_alias(catan, _catan)
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#define MAXNUM 1.0e308
|
||
|
|
|
||
|
|
double complex
|
||
|
|
catan(double complex z)
|
||
|
|
{
|
||
|
|
double complex w;
|
||
|
|
double a, t, x, x2, y;
|
||
|
|
|
||
|
|
x = creal(z);
|
||
|
|
y = cimag(z);
|
||
|
|
|
||
|
|
if ((x == 0.0) && (y > 1.0))
|
||
|
|
goto ovrf;
|
||
|
|
|
||
|
|
x2 = x * x;
|
||
|
|
a = 1.0 - x2 - (y * y);
|
||
|
|
if (a == 0.0)
|
||
|
|
goto ovrf;
|
||
|
|
|
||
|
|
t = 0.5 * atan2(2.0 * x, a);
|
||
|
|
w = _redupi(t);
|
||
|
|
|
||
|
|
t = y - 1.0;
|
||
|
|
a = x2 + (t * t);
|
||
|
|
if (a == 0.0)
|
||
|
|
goto ovrf;
|
||
|
|
|
||
|
|
t = y + 1.0;
|
||
|
|
a = (x2 + (t * t))/a;
|
||
|
|
w = w + (0.25 * log(a)) * I;
|
||
|
|
return w;
|
||
|
|
|
||
|
|
ovrf:
|
||
|
|
#if 0
|
||
|
|
mtherr ("catan", OVERFLOW);
|
||
|
|
#endif
|
||
|
|
w = MAXNUM + MAXNUM * I;
|
||
|
|
return w;
|
||
|
|
}
|