diff options
Diffstat (limited to 'DSP/Source/ControllerFunctions/arm_sin_cos_f32.c')
| -rw-r--r-- | DSP/Source/ControllerFunctions/arm_sin_cos_f32.c | 172 |
1 files changed, 87 insertions, 85 deletions
diff --git a/DSP/Source/ControllerFunctions/arm_sin_cos_f32.c b/DSP/Source/ControllerFunctions/arm_sin_cos_f32.c index 7ec1b53..12a1c83 100644 --- a/DSP/Source/ControllerFunctions/arm_sin_cos_f32.c +++ b/DSP/Source/ControllerFunctions/arm_sin_cos_f32.c @@ -3,13 +3,13 @@ * Title: arm_sin_cos_f32.c * Description: Sine and Cosine calculation for floating-point values * - * $Date: 27. January 2017 - * $Revision: V.1.5.1 + * $Date: 18. March 2019 + * $Revision: V1.6.0 * * Target Processor: Cortex-M cores * -------------------------------------------------------------------- */ /* - * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved. + * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved. * * SPDX-License-Identifier: Apache-2.0 * @@ -30,115 +30,117 @@ #include "arm_common_tables.h" /** - * @ingroup groupController + @ingroup groupController */ /** - * @defgroup SinCos Sine Cosine - * - * Computes the trigonometric sine and cosine values using a combination of table lookup - * and linear interpolation. - * There are separate functions for Q31 and floating-point data types. - * The input to the floating-point version is in degrees while the - * fixed-point Q31 have a scaled input with the range - * [-1 0.9999] mapping to [-180 +180] degrees. - * - * The floating point function also allows values that are out of the usual range. When this happens, the function will - * take extra time to adjust the input value to the range of [-180 180]. - * - * The result is accurate to 5 digits after the decimal point. - * - * The implementation is based on table lookup using 360 values together with linear interpolation. - * The steps used are: - * -# Calculation of the nearest integer table index. - * -# Compute the fractional portion (fract) of the input. - * -# Fetch the value corresponding to \c index from sine table to \c y0 and also value from \c index+1 to \c y1. - * -# Sine value is computed as <code> *psinVal = y0 + (fract * (y1 - y0))</code>. - * -# Fetch the value corresponding to \c index from cosine table to \c y0 and also value from \c index+1 to \c y1. - * -# Cosine value is computed as <code> *pcosVal = y0 + (fract * (y1 - y0))</code>. + @defgroup SinCos Sine Cosine + + Computes the trigonometric sine and cosine values using a combination of table lookup + and linear interpolation. + There are separate functions for Q31 and floating-point data types. + The input to the floating-point version is in degrees while the + fixed-point Q31 have a scaled input with the range + [-1 0.9999] mapping to [-180 +180] degrees. + + The floating point function also allows values that are out of the usual range. When this happens, the function will + take extra time to adjust the input value to the range of [-180 180]. + + The result is accurate to 5 digits after the decimal point. + + The implementation is based on table lookup using 360 values together with linear interpolation. + The steps used are: + -# Calculation of the nearest integer table index. + -# Compute the fractional portion (fract) of the input. + -# Fetch the value corresponding to \c index from sine table to \c y0 and also value from \c index+1 to \c y1. + -# Sine value is computed as <code> *psinVal = y0 + (fract * (y1 - y0))</code>. + -# Fetch the value corresponding to \c index from cosine table to \c y0 and also value from \c index+1 to \c y1. + -# Cosine value is computed as <code> *pcosVal = y0 + (fract * (y1 - y0))</code>. */ - /** - * @addtogroup SinCos - * @{ +/** + @addtogroup SinCos + @{ */ /** - * @brief Floating-point sin_cos function. - * @param[in] theta input value in degrees - * @param[out] *pSinVal points to the processed sine output. - * @param[out] *pCosVal points to the processed cos output. - * @return none. + @brief Floating-point sin_cos function. + @param[in] theta input value in degrees + @param[out] pSinVal points to processed sine output + @param[out] pCosVal points to processed cosine output + @return none */ void arm_sin_cos_f32( - float32_t theta, - float32_t * pSinVal, - float32_t * pCosVal) + float32_t theta, + float32_t * pSinVal, + float32_t * pCosVal) { - float32_t fract, in; /* Temporary variables for input, output */ - uint16_t indexS, indexC; /* Index variable */ - float32_t f1, f2, d1, d2; /* Two nearest output values */ - float32_t findex, Dn, Df, temp; + float32_t fract, in; /* Temporary input, output variables */ + uint16_t indexS, indexC; /* Index variable */ + float32_t f1, f2, d1, d2; /* Two nearest output values */ + float32_t Dn, Df; + float32_t temp, findex; - /* input x is in degrees */ - /* Scale the input, divide input by 360, for cosine add 0.25 (pi/2) to read sine table */ - in = theta * 0.00277777777778f; + /* input x is in degrees */ + /* Scale input, divide input by 360, for cosine add 0.25 (pi/2) to read sine table */ + in = theta * 0.00277777777778f; - if (in < 0.0f) - { - in = -in; - } + if (in < 0.0f) + { + in = -in; + } - in = in - (int32_t)in; + in = in - (int32_t)in; - /* Calculation of index of the table */ - findex = (float32_t) FAST_MATH_TABLE_SIZE * in; - indexS = ((uint16_t)findex) & 0x1ff; - indexC = (indexS + (FAST_MATH_TABLE_SIZE / 4)) & 0x1ff; + /* Calculate the nearest index */ + findex = (float32_t)FAST_MATH_TABLE_SIZE * in; + indexS = ((uint16_t)findex) & 0x1ff; + indexC = (indexS + (FAST_MATH_TABLE_SIZE / 4)) & 0x1ff; - /* fractional value calculation */ - fract = findex - (float32_t) indexS; + /* Calculation of fractional value */ + fract = findex - (float32_t) indexS; - /* Read two nearest values of input value from the cos & sin tables */ - f1 = sinTable_f32[indexC+0]; - f2 = sinTable_f32[indexC+1]; - d1 = -sinTable_f32[indexS+0]; - d2 = -sinTable_f32[indexS+1]; + /* Read two nearest values of input value from the cos & sin tables */ + f1 = sinTable_f32[indexC ]; + f2 = sinTable_f32[indexC+1]; + d1 = -sinTable_f32[indexS ]; + d2 = -sinTable_f32[indexS+1]; - temp = (1.0f - fract) * f1 + fract * f2; + temp = (1.0f - fract) * f1 + fract * f2; - Dn = 0.0122718463030f; // delta between the two points (fixed), in this case 2*pi/FAST_MATH_TABLE_SIZE - Df = f2 - f1; // delta between the values of the functions + Dn = 0.0122718463030f; /* delta between the two points (fixed), in this case 2*pi/FAST_MATH_TABLE_SIZE */ + Df = f2 - f1; /* delta between the values of the functions */ - temp = Dn *(d1 + d2) - 2 * Df; - temp = fract * temp + (3 * Df - (d2 + 2 * d1) * Dn); - temp = fract * temp + d1 * Dn; + temp = Dn * (d1 + d2) - 2 * Df; + temp = fract * temp + (3 * Df - (d2 + 2 * d1) * Dn); + temp = fract * temp + d1 * Dn; - /* Calculation of cosine value */ - *pCosVal = fract * temp + f1; + /* Calculation of cosine value */ + *pCosVal = fract * temp + f1; - /* Read two nearest values of input value from the cos & sin tables */ - f1 = sinTable_f32[indexS+0]; - f2 = sinTable_f32[indexS+1]; - d1 = sinTable_f32[indexC+0]; - d2 = sinTable_f32[indexC+1]; + /* Read two nearest values of input value from the cos & sin tables */ + f1 = sinTable_f32[indexS ]; + f2 = sinTable_f32[indexS+1]; + d1 = sinTable_f32[indexC ]; + d2 = sinTable_f32[indexC+1]; - temp = (1.0f - fract) * f1 + fract * f2; + temp = (1.0f - fract) * f1 + fract * f2; - Df = f2 - f1; // delta between the values of the functions - temp = Dn*(d1 + d2) - 2*Df; - temp = fract*temp + (3*Df - (d2 + 2*d1)*Dn); - temp = fract*temp + d1*Dn; + Df = f2 - f1; // delta between the values of the functions + temp = Dn * (d1 + d2) - 2 * Df; + temp = fract * temp + (3 * Df - (d2 + 2 * d1) * Dn); + temp = fract * temp + d1 * Dn; - /* Calculation of sine value */ - *pSinVal = fract*temp + f1; + /* Calculation of sine value */ + *pSinVal = fract * temp + f1; - if (theta < 0.0f) - { - *pSinVal = -*pSinVal; - } + if (theta < 0.0f) + { + *pSinVal = -*pSinVal; + } } + /** - * @} end of SinCos group + @} end of SinCos group */ |