diff options
Diffstat (limited to 'lib/libm/noieee_src/n_cpow.c')
-rw-r--r-- | lib/libm/noieee_src/n_cpow.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/lib/libm/noieee_src/n_cpow.c b/lib/libm/noieee_src/n_cpow.c new file mode 100644 index 00000000000..85cb93c228a --- /dev/null +++ b/lib/libm/noieee_src/n_cpow.c @@ -0,0 +1,71 @@ +/* $OpenBSD: n_cpow.c,v 1.1 2008/10/07 22:25:53 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. + */ + +/* cpow + * + * Complex power function + * + * + * + * SYNOPSIS: + * + * double complex cpow(); + * double complex a, z, w; + * + * w = cpow (a, z); + * + * + * + * DESCRIPTION: + * + * Raises complex A to the complex Zth power. + * Definition is per AMS55 # 4.2.8, + * analytically equivalent to cpow(a,z) = cexp(z clog(a)). + * + * ACCURACY: + * + * Relative error: + * arithmetic domain # trials peak rms + * IEEE -10,+10 30000 9.4e-15 1.5e-15 + * + */ + +#include <complex.h> +#include <math.h> + +double complex +cpow(double complex a, double complex z) +{ + double complex w; + double x, y, r, theta, absa, arga; + + x = creal (z); + y = cimag (z); + absa = cabs (a); + if (absa == 0.0) { + return (0.0 + 0.0 * I); + } + arga = carg (a); + r = pow (absa, x); + theta = x * arga; + if (y != 0.0) { + r = r * exp (-y * arga); + theta = theta + y * log (absa); + } + w = r * cos (theta) + (r * sin (theta)) * I; + return (w); +} |