OpenLibm/src/s_casinf.c
Ed Schouten 7e5585aaca Rename openlibm.h to openlibm_math.h.
This is a bit more consistent with the naming of the other header files
(openlibm_complex.h and openlibm_fenv.h). Re-add an openlibm.h header
that includes all of the public headers as a shorthand.

Fix up all of the source files to include <openlibm_math.h> instead of
<openlibm.h>. While there, fix ordering of the includes.
2015-01-11 23:37:01 +01:00

132 lines
2.6 KiB
C

/* $OpenBSD: s_casinf.c,v 1.3 2011/07/20 19:28:33 martynas Exp $ */
/*
* Copyright (c) 2008 Stephen L. Moshier <steve@moshier.net>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* casinf()
*
* Complex circular arc sine
*
*
*
* SYNOPSIS:
*
* void casinf();
* cmplxf z, w;
*
* casinf( &z, &w );
*
*
*
* DESCRIPTION:
*
* Inverse complex sine:
*
* 2
* w = -i clog( iz + csqrt( 1 - z ) ).
*
*
* ACCURACY:
*
* Relative error:
* arithmetic domain # trials peak rms
* IEEE -10,+10 30000 1.1e-5 1.5e-6
* Larger relative error can be observed for z near zero.
*
*/
#include <openlibm_complex.h>
#include <openlibm_math.h>
float complex
casinf(float complex z)
{
float complex w;
float x, y;
static float complex ca, ct, zz, z2;
/*
float cn, n;
static float a, b, s, t, u, v, y2;
static cmplxf sum;
*/
x = crealf(z);
y = cimagf(z);
if(y == 0.0f) {
if(fabsf(x) > 1.0f) {
w = (float)M_PI_2 + 0.0f * I;
/*mtherr( "casinf", DOMAIN );*/
}
else {
w = asinf (x) + 0.0f * I;
}
return (w);
}
/* Power series expansion */
/*
b = cabsf(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 = fabsf(ct.r) + fabsf(ct.i);
}
while(b > MACHEPF);
w->r = sum.r;
w->i = sum.i;
return;
}
*/
ca = x + y * I;
ct = ca * I; /* iz */
/* sqrt( 1 - z*z) */
/* cmul( &ca, &ca, &zz ) */
/*x * x - y * y */
zz = (x - y) * (x + y) + (2.0f * x * y) * I;
zz = 1.0f - crealf(zz) - cimagf(zz) * I;
z2 = csqrtf (zz);
zz = ct + z2;
zz = clogf (zz);
/* multiply by 1/i = -i */
w = zz * (-1.0f * I);
return (w);
}