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author | Lorenz Meier <lm@inf.ethz.ch> | 2013-06-01 01:04:32 +0200 |
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committer | Lorenz Meier <lm@inf.ethz.ch> | 2013-06-01 01:04:32 +0200 |
commit | 5375bb5b86e266157ceceef08c367da711b8144e (patch) | |
tree | 88bc81cab11d8f0b2b6f9391f803051c081b2ecb /nuttx/libc/math/lib_sqrt.c | |
parent | 27ee36b2049167a1272122548fe61aa2993d79c1 (diff) | |
download | px4-firmware-5375bb5b86e266157ceceef08c367da711b8144e.tar.gz px4-firmware-5375bb5b86e266157ceceef08c367da711b8144e.tar.bz2 px4-firmware-5375bb5b86e266157ceceef08c367da711b8144e.zip |
Cleanup, WIP, needs a NuttX checkout to Firmware/NuttX now
Diffstat (limited to 'nuttx/libc/math/lib_sqrt.c')
-rw-r--r-- | nuttx/libc/math/lib_sqrt.c | 99 |
1 files changed, 0 insertions, 99 deletions
diff --git a/nuttx/libc/math/lib_sqrt.c b/nuttx/libc/math/lib_sqrt.c deleted file mode 100644 index e8a1c42ea..000000000 --- a/nuttx/libc/math/lib_sqrt.c +++ /dev/null @@ -1,99 +0,0 @@ -/************************************************************************ - * libc/math/lib_sqrt.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) 2009-2011 Nick Johnson <nickbjohnson4224 at gmail.com> - * - * 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 <nuttx/config.h> -#include <nuttx/compiler.h> - -#include <math.h> -#include <errno.h> - -#include "lib_internal.h" - -/************************************************************************ - * Public Functions - ************************************************************************/ - -#ifdef CONFIG_HAVE_DOUBLE -double sqrt(double x) -{ - long double y, y1; - - if (x < 0.0) - { - errno = EDOM; - return NAN; - } - - if (isnan(x)) - { - return NAN; - } - - if (isinf(x)) - { - return INFINITY; - } - - if (x == 0.0) - { - return 0.0; - } - - /* Guess square root (using bit manipulation) */ - - y = lib_sqrtapprox(x); - - /* Perform four iterations of approximation. This number (4) is - * definitely optimal - */ - - y = 0.5 * (y + x / y); - y = 0.5 * (y + x / y); - y = 0.5 * (y + x / y); - y = 0.5 * (y + x / y); - - /* If guess was terribe (out of range of float). Repeat approximation - * until convergence. - */ - - if (y * y < x - 1.0 || y * y > x + 1.0) - { - y1 = -1.0; - while (y != y1) - { - y1 = y; - y = 0.5 * (y + x / y); - } - } - - return y; -} -#endif |