From f37278039ad4c2f0bfcfaed647b01aa70ae0b5d6 Mon Sep 17 00:00:00 2001 From: patacongo Date: Sat, 10 Nov 2012 16:06:01 +0000 Subject: Trying to recover from deleted directory contents git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5329 42af7a65-404d-4744-a932-0658087f49c3 --- nuttx/lib/math/lib_tanhf.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 nuttx/lib/math/lib_tanhf.c (limited to 'nuttx/lib/math/lib_tanhf.c') diff --git a/nuttx/lib/math/lib_tanhf.c b/nuttx/lib/math/lib_tanhf.c new file mode 100644 index 000000000..94d15cc60 --- /dev/null +++ b/nuttx/lib/math/lib_tanhf.c @@ -0,0 +1,44 @@ +/************************************************************************ + * lib/math/lib_tanhf.c + * + * This file is a part of NuttX: + * + * Copyright (C) 2012 Gregory Nutt. All rights reserved. + * Ported by: Darcy Gong + * + * It derives from the Rhombs OS math library by Nick Johnson which has + * a compatibile, MIT-style license: + * + * Copyright (C) 2009, 2010 Nick Johnson + * + * 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. + * + ************************************************************************/ + +/************************************************************************ + * Included Files + ************************************************************************/ + +#include + +/************************************************************************ + * Public Functions + ************************************************************************/ + +float tanhf(float x) +{ + float x0 = expf(x); + float x1 = 1.0 / x0; + + return ((x0 + x1) / (x0 - x1)); +} -- cgit v1.2.3