diff options
Diffstat (limited to 'Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_atan2_f32.c')
| -rw-r--r-- | Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_atan2_f32.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_atan2_f32.c b/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_atan2_f32.c new file mode 100644 index 0000000..3e398f7 --- /dev/null +++ b/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_atan2_f32.c @@ -0,0 +1,183 @@ +/* ---------------------------------------------------------------------- + * Project: CMSIS DSP Library + * Title: arm_atan2_f32.c + * Description: float32 Arc tangent of y/x + * + * $Date: 22 April 2022 + * $Revision: V1.10.0 + * + * Target Processor: Cortex-M and Cortex-A cores + * -------------------------------------------------------------------- */ +/* + * Copyright (C) 2010-2022 ARM Limited or its affiliates. All rights reserved. + * + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the License); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an AS IS BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "dsp/fast_math_functions.h" + +/* + +atan for argument between in [0, 1.0] + + +*/ + +#define ATANHALFF32 0.463648f +#define PIHALFF32 1.5707963267948966192313f + +#define ATAN2_NB_COEFS_F32 10 + +static const float32_t atan2_coefs_f32[ATAN2_NB_COEFS_F32]={0.0f +,1.0000001638308195518f +,-0.0000228941363602264f +,-0.3328086544578890873f +,-0.004404814619311061f +,0.2162217461808173258f +,-0.0207504842057097504f +,-0.1745263362250363339f +,0.1340557235283553386f +,-0.0323664125927477625f +}; + +__STATIC_FORCEINLINE float32_t arm_atan_limited_f32(float32_t x) +{ + float32_t res=atan2_coefs_f32[ATAN2_NB_COEFS_F32-1]; + int i=1; + for(i=1;i<ATAN2_NB_COEFS_F32;i++) + { + res = x*res + atan2_coefs_f32[ATAN2_NB_COEFS_F32-1-i]; + } + + + return(res); +} + +__STATIC_FORCEINLINE float32_t arm_atan_f32(float32_t x) +{ + int sign=0; + float32_t res=0.0f; + + if (x < 0.0f) + { + sign=1; + x=-x; + } + + if (x > 1.0f) + { + x = 1.0f / x; + res = PIHALFF32 - arm_atan_limited_f32(x); + } + else + { + res += arm_atan_limited_f32(x); + } + + + if (sign) + { + res = -res; + } + + return(res); +} + + +/** + @ingroup groupFastMath + */ + +/** + @defgroup atan2 ArcTan2 + + Computing Arc tangent only using the ratio y/x is not enough to determine the angle + since there is an indeterminacy. Opposite quadrants are giving the same ratio. + + ArcTan2 is not using y/x to compute the angle but y and x and use the sign of y and x + to determine the quadrant. + + */ + +/** + @addtogroup atan2 + @{ + */ + +/** + @brief Arc Tangent of y/x using sign of y and x to get right quadrant + @param[in] y y coordinate + @param[in] x x coordinate + @param[out] result Result + @return error status. + + @par Compute the Arc tangent of y/x: + The sign of y and x are used to determine the right quadrant + and compute the right angle. +*/ + + +arm_status arm_atan2_f32(float32_t y,float32_t x,float32_t *result) +{ + if (x > 0.0f) + { + *result=arm_atan_f32(y/x); + return(ARM_MATH_SUCCESS); + } + if (x < 0.0f) + { + if (y > 0.0f) + { + *result=arm_atan_f32(y/x) + PI; + } + else if (y < 0.0f) + { + *result=arm_atan_f32(y/x) - PI; + } + else + { + if (signbit(y)) + { + *result= -PI; + } + else + { + *result= PI; + } + } + return(ARM_MATH_SUCCESS); + } + if (x == 0.0f) + { + if (y > 0.0f) + { + *result=PIHALFF32; + return(ARM_MATH_SUCCESS); + } + if (y < 0.0f) + { + *result=-PIHALFF32; + return(ARM_MATH_SUCCESS); + } + } + + + return(ARM_MATH_NANINF); + +} + +/** + @} end of atan2 group + */ |