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Diffstat (limited to 'lib/mlibc/options/ansi/generic/complex/casin.c')
| -rw-r--r-- | lib/mlibc/options/ansi/generic/complex/casin.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/lib/mlibc/options/ansi/generic/complex/casin.c b/lib/mlibc/options/ansi/generic/complex/casin.c new file mode 100644 index 0000000..5019fd8 --- /dev/null +++ b/lib/mlibc/options/ansi/generic/complex/casin.c @@ -0,0 +1,165 @@ +/* $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> + */ + +/* +FUNCTION + <<casin>>, <<casinf>>---complex arc sine + +INDEX + casin +INDEX + casinf + +ANSI_SYNOPSIS + #include <complex.h> + double complex casin(double complex <[z]>); + float complex casinf(float complex <[z]>); + + +DESCRIPTION + These functions compute the complex arc sine of <[z]>, + with branch cuts outside the interval [-1, +1] along the real axis. + + <<casinf>> is identical to <<casin>>, except that it performs + its calculations on <<floats complex>>. + +RETURNS + @ifnottex + These functions return the complex arc sine value, in the range + of a strip mathematically unbounded along the imaginary axis + and in the interval [-pi/2, +pi/2] along the real axis. + @end ifnottex + @tex + These functions return the complex arc sine value, in the range + of a strip mathematically unbounded along the imaginary axis + and in the interval [$-\pi/2$, $+\pi/2$] along the real axis. + @end tex + +PORTABILITY + <<casin>> and <<casinf>> are ISO C99 + +QUICKREF + <<casin>> and <<casinf>> are ISO C99 + +*/ + + +#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; +} |