diff options
Diffstat (limited to 'nuttx/lib/math/lib_asin.c')
-rw-r--r-- | nuttx/lib/math/lib_asin.c | 107 |
1 files changed, 44 insertions, 63 deletions
diff --git a/nuttx/lib/math/lib_asin.c b/nuttx/lib/math/lib_asin.c index 9d72e8042..1469d1ed8 100644 --- a/nuttx/lib/math/lib_asin.c +++ b/nuttx/lib/math/lib_asin.c @@ -1,4 +1,14 @@ -/* +/************************************************************************ + * lib/math/lib_sin.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 @@ -12,77 +22,48 @@ * 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. - */ + * + ************************************************************************/ -#include <apps/math.h> -#include <float.h> - -float asinf(float x) { - long double y, y_sin, y_cos; - - y = 0; - - while (1) { - y_sin = sinf(y); - y_cos = cosf(y); - - if (y > M_PI_2 || y < -M_PI_2) { - y = fmodf(y, M_PI); - } - - if (y_sin + DBL_EPSILON >= x && y_sin - DBL_EPSILON <= x) { - break; - } - - y = y - (y_sin - x) / y_cos; - } - - return y; -} - -double asin(double x) { - long double y, y_sin, y_cos; - - y = 0; - - while (1) { - y_sin = sin(y); - y_cos = cos(y); +/************************************************************************ + * Included Files + ************************************************************************/ - if (y > M_PI_2 || y < -M_PI_2) { - y = fmod(y, M_PI); - } +#include <nuttx/config.h> +#include <nuttx/compiler.h> - if (y_sin + DBL_EPSILON >= x && y_sin - DBL_EPSILON <= x) { - break; - } - - y = y - (y_sin - x) / y_cos; - } +#include <math.h> +#include <float.h> - return y; -} +/************************************************************************ + * Public Functions + ************************************************************************/ -long double asinl(long double x) { - long double y, y_sin, y_cos; +#if CONFIG_HAVE_DOUBLE +double asin(double x) +{ + long double y, y_sin, y_cos; - y = 0; + y = 0; - while (1) { - y_sin = sinl(y); - y_cos = cosl(y); + while (1) + { + y_sin = sin(y); + y_cos = cos(y); - if (y > M_PI_2 || y < -M_PI_2) { - y = fmodl(y, M_PI); - } + if (y > M_PI_2 || y < -M_PI_2) + { + y = fmod(y, M_PI); + } - if (y_sin + LDBL_EPSILON >= x && y_sin - LDBL_EPSILON <= x) { - break; - } + if (y_sin + DBL_EPSILON >= x && y_sin - DBL_EPSILON <= x) + { + break; + } - y = y - (y_sin - x) / y_cos; - } + y = y - (y_sin - x) / y_cos; + } - return y; + return y; } - +#endif |