extend cmath (some of the functions are dummy)

[libm] / src / cmath / cpow.c

diff --git a/src/cmath/cpow.c b/src/cmath/cpow.c
index 0bc36d3..f863588 100644 (file)
--- a/src/cmath/cpow.c
+++ b/src/cmath/cpow.c
@@ -1,61 +1,8 @@
-/* origin: OpenBSD /usr/src/lib/libm/src/s_cpow.c */
-/*
- * 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.
- */
-/*
- *      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 "libm.h"
 
-double complex cpow(double complex a, double complex z)
-{
-       double x, y, r, theta, absa, arga;
+/* pow(z, c) = exp(c log(z)), See C99 G.6.4.1 */
 
-       x = creal(z);
-       y = cimag(z);
-       absa = cabs(a);
-       if (absa == 0.0)
-               return 0.0;
-       arga = carg(a);
-       r = pow(absa, x);
-       theta = x * arga;
-       if (y != 0.0) {
-               r = r * exp(-y * arga);
-               theta += y * log(absa);
-       }
-       return cpack(r * cos(theta), (r * sin(theta)));
+double complex cpow(double complex z, double complex c)
+{
+       return cexp(c * clog(z));
 }