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Diffstat (limited to 'lib/mlibc/options/ansi/generic/complex/catan.c')
| -rw-r--r-- | lib/mlibc/options/ansi/generic/complex/catan.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/lib/mlibc/options/ansi/generic/complex/catan.c b/lib/mlibc/options/ansi/generic/complex/catan.c new file mode 100644 index 0000000..0cf4739 --- /dev/null +++ b/lib/mlibc/options/ansi/generic/complex/catan.c @@ -0,0 +1,130 @@ +/* $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> + */ + +/* +FUNCTION + <<catan>>, <<catanf>>---complex arc tangent + +INDEX + catan +INDEX + catanf + +ANSI_SYNOPSIS + #include <complex.h> + double complex catan(double complex <[z]>); + float complex catanf(float complex <[z]>); + + +DESCRIPTION + @ifnottex + These functions compute the complex arc tangent of <[z]>, + with branch cuts outside the interval [-i, +i] along the + imaginary axis. + @end ifnottex + @tex + These functions compute the complex arc tangent of <[z]>, + with branch cuts outside the interval [$-i$, $+i$] along the + imaginary axis. + @end tex + + <<catanf>> is identical to <<catan>>, except that it performs + its calculations on <<floats complex>>. + +RETURNS + @ifnottex + These functions return the complex arc tangent 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 tangent, 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 + <<catan>> and <<catanf>> are ISO C99 + +QUICKREF + <<catan>> and <<catanf>> are ISO C99 + +*/ + + +#include <complex.h> +#include <math.h> +#include "cephes_subr.h" + +#ifdef __weak_alias +__weak_alias(catan, _catan) +#endif + +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 = __mlibc_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 = HUGE_VAL + HUGE_VAL * I; + return w; +} |