extend cmath (some of the functions are dummy)

[libm] / src / cmath / catanh.c

diff --git a/src/cmath/catanh.c b/src/cmath/catanh.c
index 5545747..b162802 100644 (file)
--- a/src/cmath/catanh.c
+++ b/src/cmath/catanh.c
@@ -1,47 +1,9 @@
-/* origin: OpenBSD /usr/src/lib/libm/src/s_catanh.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 inverse hyperbolic tangent
- *
- *
- * SYNOPSIS:
- *
- * double complex catanh();
- * double complex z, w;
- *
- * w = catanh (z);
- *
- *
- * DESCRIPTION:
- *
- * Inverse tanh, equal to  -i catan (iz);
- *
- * ACCURACY:
- *
- *                      Relative error:
- * arithmetic   domain     # trials      peak         rms
- *    IEEE      -10,+10     30000       2.3e-16     6.2e-17
- *
- */
-
 #include "libm.h"
 
+/* atanh = -i atan(i z) */
+
 double complex catanh(double complex z)
 {
-       // FIXME: -i, reeval
-       return -1.0 * I * catan(z * I);
+       z = catan(cpack(-cimag(z), creal(z)));
+       return cpack(cimag(z), -creal(z));
 }