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Diffstat (limited to 'lib/mlibc/options/ansi/generic/complex/cproj.c')
-rw-r--r-- | lib/mlibc/options/ansi/generic/complex/cproj.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/lib/mlibc/options/ansi/generic/complex/cproj.c b/lib/mlibc/options/ansi/generic/complex/cproj.c new file mode 100644 index 0000000..0ed50f2 --- /dev/null +++ b/lib/mlibc/options/ansi/generic/complex/cproj.c @@ -0,0 +1,105 @@ +/* $NetBSD: cproj.c,v 1.3 2010/09/20 17:51:38 christos Exp $ */ + +/*- + * Copyright (c) 2010 The NetBSD Foundation, Inc. + * All rights reserved. + * + * 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 + <<cproj>>, <<cprojf>>--- Riemann sphere projection + +INDEX + cproj +INDEX + cprojf + +ANSI_SYNOPSIS + #include <complex.h> + double complex cproj(double complex <[z]>); + float complex cprojf(float complex <[z]>); + + +DESCRIPTION + These functions compute a projection of <[z]> onto the Riemann + sphere: <[z]> projects to <[z]> except that all complex infinities + (even those with one infinite part and one NaN part) project + to positive infinity on the real axis. If <[z]> has an infinite part, + then <<cproj>>(<[z]>) is equivalent to + + INFINITY + I * copysign(0.0, cimag(z)) + + <<cprojf>> is identical to <<cproj>>, except that it performs + its calculations on <<floats complex>>. + +RETURNS + The cproj functions return the value of the projection onto + the Riemann sphere. + +PORTABILITY + <<cproj>> and <<cprojf>> are ISO C99 + +QUICKREF + <<cproj>> and <<cprojf>> are ISO C99 + +*/ + +/*__RCSID("$NetBSD: cproj.c,v 1.3 2010/09/20 17:51:38 christos Exp $"); */ + +#include <complex.h> +#include <math.h> + +#include "fdlibm.h" + +/* + * cproj(double complex z) + * + * These functions return the value of the projection (not stereographic!) + * onto the Riemann sphere. + * + * z projects to z, except that all complex infinities (even those with one + * infinite part and one NaN part) project to positive infinity on the real axis. + * If z has an infinite part, then cproj(z) shall be equivalent to: + * + * INFINITY + I * copysign(0.0, cimag(z)) + */ +double complex +cproj(double complex z) +{ + double_complex w = { .z = z }; + + if (isinf(creal(z)) || isinf(cimag(z))) { +#ifdef __INFINITY + REAL_PART(w) = __INFINITY; +#else + REAL_PART(w) = INFINITY; +#endif + IMAG_PART(w) = copysign(0.0, cimag(z)); + } + + return (w.z); +} |