diff options
Diffstat (limited to 'nuttx/lib/math/lib_sin.c')
| -rw-r--r-- | nuttx/lib/math/lib_sin.c | 234 |
1 files changed, 98 insertions, 136 deletions
diff --git a/nuttx/lib/math/lib_sin.c b/nuttx/lib/math/lib_sin.c index e862104fd..2d21d2309 100644 --- a/nuttx/lib/math/lib_sin.c +++ b/nuttx/lib/math/lib_sin.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 @@ -12,141 +22,93 @@ * 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 <stdint.h> -#include <unistd.h> -#include <float.h> -#include <apps/math.h> - -static float _flt_inv_fact[] = { - 1.0 / 1.0, // 1 / 1! - 1.0 / 6.0, // 1 / 3! - 1.0 / 120.0, // 1 / 5! - 1.0 / 5040.0, // 1 / 7! - 1.0 / 362880.0, // 1 / 9! - 1.0 / 39916800.0, // 1 / 11! + * + ************************************************************************/ + +/************************************************************************ + * Included Files + ************************************************************************/ + +#include <nuttx/config.h> +#include <nuttx/compiler.h> + +#include <sys/types.h> +#include <math.h> + +#if CONFIG_HAVE_DOUBLE + +/************************************************************************ + * Private Data + ************************************************************************/ + +static double _dbl_inv_fact[] = +{ + 1.0 / 1.0, // 1 / 1! + 1.0 / 6.0, // 1 / 3! + 1.0 / 120.0, // 1 / 5! + 1.0 / 5040.0, // 1 / 7! + 1.0 / 362880.0, // 1 / 9! + 1.0 / 39916800.0, // 1 / 11! + 1.0 / 6227020800.0, // 1 / 13! + 1.0 / 1307674368000.0, // 1 / 15! + 1.0 / 355687428096000.0, // 1 / 17! + 1.0 / 121645100408832000.0, // 1 / 19! }; -float sinf(float x) { - float x_squared; - float sin_x; - size_t i; - - /* move x to [-pi, pi) */ - x = fmodf(x, 2 * M_PI); - if (x >= M_PI) x -= 2 * M_PI; - if (x < -M_PI) x += 2 * M_PI; - - /* move x to [-pi/2, pi/2) */ - if (x >= M_PI_2) x = M_PI - x; - if (x < -M_PI_2) x = -M_PI - x; - - x_squared = x * x; - sin_x = 0.0; - - /* perform Taylor series approximation for sin(x) with six terms */ - for (i = 0; i < 6; i++) { - if (i % 2 == 0) { - sin_x += x * _flt_inv_fact[i]; - } - else { - sin_x -= x * _flt_inv_fact[i]; - } - - x *= x_squared; - } - - return sin_x; +/************************************************************************ + * Public Functions + ************************************************************************/ + +double sin(double x) +{ + double x_squared; + double sin_x; + size_t i; + + /* Move x to [-pi, pi) */ + + x = fmod(x, 2 * M_PI); + if (x >= M_PI) + { + x -= 2 * M_PI; + } + + if (x < -M_PI) + { + x += 2 * M_PI; + } + + /* Move x to [-pi/2, pi/2) */ + + if (x >= M_PI_2) + { + x = M_PI - x; + } + + if (x < -M_PI_2) + { + x = -M_PI - x; + } + + x_squared = x * x; + sin_x = 0.0; + + /* Perform Taylor series approximation for sin(x) with ten terms */ + + for (i = 0; i < 10; i++) + { + if (i % 2 == 0) + { + sin_x += x * _dbl_inv_fact[i]; + } + else + { + sin_x -= x * _dbl_inv_fact[i]; + } + + x *= x_squared; + } + + return sin_x; } - -static double _dbl_inv_fact[] = { - 1.0 / 1.0, // 1 / 1! - 1.0 / 6.0, // 1 / 3! - 1.0 / 120.0, // 1 / 5! - 1.0 / 5040.0, // 1 / 7! - 1.0 / 362880.0, // 1 / 9! - 1.0 / 39916800.0, // 1 / 11! - 1.0 / 6227020800.0, // 1 / 13! - 1.0 / 1307674368000.0, // 1 / 15! - 1.0 / 355687428096000.0, // 1 / 17! - 1.0 / 121645100408832000.0, // 1 / 19! -}; - -double sin(double x) { - double x_squared; - double sin_x; - size_t i; - - /* move x to [-pi, pi) */ - x = fmod(x, 2 * M_PI); - if (x >= M_PI) x -= 2 * M_PI; - if (x < -M_PI) x += 2 * M_PI; - - /* move x to [-pi/2, pi/2) */ - if (x >= M_PI_2) x = M_PI - x; - if (x < -M_PI_2) x = -M_PI - x; - - x_squared = x * x; - sin_x = 0.0; - - /* perform Taylor series approximation for sin(x) with ten terms */ - for (i = 0; i < 10; i++) { - if (i % 2 == 0) { - sin_x += x * _dbl_inv_fact[i]; - } - else { - sin_x -= x * _dbl_inv_fact[i]; - } - - x *= x_squared; - } - - return sin_x; -} - -static long double _ldbl_inv_fact[] = { - 1.0 / 1.0, // 1 / 1! - 1.0 / 6.0, // 1 / 3! - 1.0 / 120.0, // 1 / 5! - 1.0 / 5040.0, // 1 / 7! - 1.0 / 362880.0, // 1 / 9! - 1.0 / 39916800.0, // 1 / 11! - 1.0 / 6227020800.0, // 1 / 13! - 1.0 / 1307674368000.0, // 1 / 15! - 1.0 / 355687428096000.0, // 1 / 17! - 1.0 / 121645100408832000.0, // 1 / 19! -}; - -long double sinl(long double x) { - long double x_squared; - long double sin_x; - size_t i; - - /* move x to [-pi, pi) */ - x = fmodl(x, 2 * M_PI); - if (x >= M_PI) x -= 2 * M_PI; - if (x < -M_PI) x += 2 * M_PI; - - /* move x to [-pi/2, pi/2) */ - if (x >= M_PI_2) x = M_PI - x; - if (x < -M_PI_2) x = -M_PI - x; - - x_squared = x * x; - sin_x = 0.0; - - /* perform Taylor series approximation for sin(x) with ten terms */ - for (i = 0; i < 10; i++) { - if (i % 2 == 0) { - sin_x += x * _ldbl_inv_fact[i]; - } - else { - sin_x -= x * _ldbl_inv_fact[i]; - } - - x *= x_squared; - } - - return sin_x; -} - +#endif |