123 lines
2.9 KiB
C
123 lines
2.9 KiB
C
/* $NetBSD: casin.c,v 1.1 2007/08/20 16:01:31 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>
|
|
|
|
#ifdef __weak_alias
|
|
__weak_alias(casin, _casin)
|
|
#endif
|
|
|
|
double complex
|
|
casin(double complex z)
|
|
{
|
|
double complex w;
|
|
double complex ca, ct, zz, z2;
|
|
double x, y;
|
|
|
|
x = creal(z);
|
|
y = cimag(z);
|
|
|
|
#if 0 /* MD: test is incorrect, casin(>1) is defined */
|
|
if (y == 0.0) {
|
|
if (fabs(x) > 1.0) {
|
|
w = M_PI_2 + 0.0 * I;
|
|
#if 0
|
|
mtherr ("casin", DOMAIN);
|
|
#endif
|
|
} else {
|
|
w = asin(x) + 0.0 * I;
|
|
}
|
|
return w;
|
|
}
|
|
#endif
|
|
|
|
/* Power series expansion */
|
|
/*
|
|
b = cabs(z);
|
|
if( b < 0.125 )
|
|
{
|
|
z2.r = (x - y) * (x + y);
|
|
z2.i = 2.0 * x * y;
|
|
|
|
cn = 1.0;
|
|
n = 1.0;
|
|
ca.r = x;
|
|
ca.i = y;
|
|
sum.r = x;
|
|
sum.i = y;
|
|
do
|
|
{
|
|
ct.r = z2.r * ca.r - z2.i * ca.i;
|
|
ct.i = z2.r * ca.i + z2.i * ca.r;
|
|
ca.r = ct.r;
|
|
ca.i = ct.i;
|
|
|
|
cn *= n;
|
|
n += 1.0;
|
|
cn /= n;
|
|
n += 1.0;
|
|
b = cn/n;
|
|
|
|
ct.r *= b;
|
|
ct.i *= b;
|
|
sum.r += ct.r;
|
|
sum.i += ct.i;
|
|
b = fabs(ct.r) + fabs(ct.i);
|
|
}
|
|
while( b > MACHEP );
|
|
w->r = sum.r;
|
|
w->i = sum.i;
|
|
return;
|
|
}
|
|
*/
|
|
|
|
|
|
ca = x + y * I;
|
|
ct = ca * I;
|
|
/* sqrt( 1 - z*z) */
|
|
/* cmul( &ca, &ca, &zz ) */
|
|
/*x * x - y * y */
|
|
zz = (x - y) * (x + y) + (2.0 * x * y) * I;
|
|
|
|
zz = 1.0 - creal(zz) - cimag(zz) * I;
|
|
z2 = csqrt(zz);
|
|
|
|
zz = ct + z2;
|
|
zz = clog(zz);
|
|
/* multiply by 1/i = -i */
|
|
w = zz * (-1.0 * I);
|
|
return w;
|
|
}
|