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Diff: cmsis_dsp/FastMathFunctions/arm_sin_f32.c
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diff -r 83d0537c7d84 -r fdd22bb7aa52 cmsis_dsp/FastMathFunctions/arm_sin_f32.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/cmsis_dsp/FastMathFunctions/arm_sin_f32.c Wed Nov 28 12:30:09 2012 +0000 @@ -0,0 +1,281 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010 ARM Limited. All rights reserved. +* +* $Date: 15. February 2012 +* $Revision: V1.1.0 +* +* Project: CMSIS DSP Library +* Title: arm_sin_f32.c +* +* Description: Fast sine calculation for floating-point values. +* +* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 +* +* Version 1.1.0 2012/02/15 +* Updated with more optimizations, bug fixes and minor API changes. +* +* Version 1.0.10 2011/7/15 +* Big Endian support added and Merged M0 and M3/M4 Source code. +* +* Version 1.0.3 2010/11/29 +* Re-organized the CMSIS folders and updated documentation. +* +* Version 1.0.2 2010/11/11 +* Documentation updated. +* +* Version 1.0.1 2010/10/05 +* Production release and review comments incorporated. +* +* Version 1.0.0 2010/09/20 +* Production release and review comments incorporated. +* -------------------------------------------------------------------- */ + +#include "arm_math.h" + +/** + * @ingroup groupFastMath + */ + +/** + * @defgroup sin Sine + * + * Computes the trigonometric sine function using a combination of table lookup + * and cubic interpolation. There are separate functions for + * Q15, Q31, and floating-point data types. + * The input to the floating-point version is in radians while the + * fixed-point Q15 and Q31 have a scaled input with the range + * [0 +0.9999] mapping to [0 2*pi), Where range excludes 2*pi. + * + * The implementation is based on table lookup using 256 values together with cubic interpolation. + * The steps used are: + * -# Calculation of the nearest integer table index + * -# Fetch the four table values a, b, c, and d + * -# Compute the fractional portion (fract) of the table index. + * -# Calculation of wa, wb, wc, wd + * -# The final result equals <code>a*wa + b*wb + c*wc + d*wd</code> + * + * where + * <pre> + * a=Table[index-1]; + * b=Table[index+0]; + * c=Table[index+1]; + * d=Table[index+2]; + * </pre> + * and + * <pre> + * wa=-(1/6)*fract.^3 + (1/2)*fract.^2 - (1/3)*fract; + * wb=(1/2)*fract.^3 - fract.^2 - (1/2)*fract + 1; + * wc=-(1/2)*fract.^3+(1/2)*fract.^2+fract; + * wd=(1/6)*fract.^3 - (1/6)*fract; + * </pre> + */ + +/** + * @addtogroup sin + * @{ + */ + + +/** + * \par + * Example code for Generation of Floating-point Sin Table: + * tableSize = 256; + * <pre>for(n = -1; n < (tableSize + 1); n++) + * { + * sinTable[n+1]=sin(2*pi*n/tableSize); + * }</pre> + * \par + * where pi value is 3.14159265358979 + */ + +static const float32_t sinTable[259] = { + -0.024541229009628296f, 0.000000000000000000f, 0.024541229009628296f, + 0.049067676067352295f, 0.073564566671848297f, 0.098017141222953796f, + 0.122410677373409270f, 0.146730467677116390f, + 0.170961886644363400f, 0.195090323686599730f, 0.219101235270500180f, + 0.242980182170867920f, 0.266712754964828490f, 0.290284663438797000f, + 0.313681751489639280f, 0.336889863014221190f, + 0.359895050525665280f, 0.382683426141738890f, 0.405241310596466060f, + 0.427555084228515630f, 0.449611335992813110f, 0.471396744251251220f, + 0.492898195981979370f, 0.514102756977081300f, + 0.534997642040252690f, 0.555570244789123540f, 0.575808167457580570f, + 0.595699310302734380f, 0.615231573581695560f, 0.634393274784088130f, + 0.653172850608825680f, 0.671558976173400880f, + 0.689540565013885500f, 0.707106769084930420f, 0.724247097969055180f, + 0.740951120853424070f, 0.757208824157714840f, 0.773010432720184330f, + 0.788346409797668460f, 0.803207516670227050f, + 0.817584812641143800f, 0.831469595432281490f, 0.844853579998016360f, + 0.857728600502014160f, 0.870086967945098880f, 0.881921291351318360f, + 0.893224298954010010f, 0.903989315032958980f, + 0.914209783077239990f, 0.923879504203796390f, 0.932992815971374510f, + 0.941544055938720700f, 0.949528157711029050f, 0.956940352916717530f, + 0.963776051998138430f, 0.970031261444091800f, + 0.975702106952667240f, 0.980785250663757320f, 0.985277652740478520f, + 0.989176511764526370f, 0.992479562759399410f, 0.995184719562530520f, + 0.997290432453155520f, 0.998795449733734130f, + 0.999698817729949950f, 1.000000000000000000f, 0.999698817729949950f, + 0.998795449733734130f, 0.997290432453155520f, 0.995184719562530520f, + 0.992479562759399410f, 0.989176511764526370f, + 0.985277652740478520f, 0.980785250663757320f, 0.975702106952667240f, + 0.970031261444091800f, 0.963776051998138430f, 0.956940352916717530f, + 0.949528157711029050f, 0.941544055938720700f, + 0.932992815971374510f, 0.923879504203796390f, 0.914209783077239990f, + 0.903989315032958980f, 0.893224298954010010f, 0.881921291351318360f, + 0.870086967945098880f, 0.857728600502014160f, + 0.844853579998016360f, 0.831469595432281490f, 0.817584812641143800f, + 0.803207516670227050f, 0.788346409797668460f, 0.773010432720184330f, + 0.757208824157714840f, 0.740951120853424070f, + 0.724247097969055180f, 0.707106769084930420f, 0.689540565013885500f, + 0.671558976173400880f, 0.653172850608825680f, 0.634393274784088130f, + 0.615231573581695560f, 0.595699310302734380f, + 0.575808167457580570f, 0.555570244789123540f, 0.534997642040252690f, + 0.514102756977081300f, 0.492898195981979370f, 0.471396744251251220f, + 0.449611335992813110f, 0.427555084228515630f, + 0.405241310596466060f, 0.382683426141738890f, 0.359895050525665280f, + 0.336889863014221190f, 0.313681751489639280f, 0.290284663438797000f, + 0.266712754964828490f, 0.242980182170867920f, + 0.219101235270500180f, 0.195090323686599730f, 0.170961886644363400f, + 0.146730467677116390f, 0.122410677373409270f, 0.098017141222953796f, + 0.073564566671848297f, 0.049067676067352295f, + 0.024541229009628296f, 0.000000000000000122f, -0.024541229009628296f, + -0.049067676067352295f, -0.073564566671848297f, -0.098017141222953796f, + -0.122410677373409270f, -0.146730467677116390f, + -0.170961886644363400f, -0.195090323686599730f, -0.219101235270500180f, + -0.242980182170867920f, -0.266712754964828490f, -0.290284663438797000f, + -0.313681751489639280f, -0.336889863014221190f, + -0.359895050525665280f, -0.382683426141738890f, -0.405241310596466060f, + -0.427555084228515630f, -0.449611335992813110f, -0.471396744251251220f, + -0.492898195981979370f, -0.514102756977081300f, + -0.534997642040252690f, -0.555570244789123540f, -0.575808167457580570f, + -0.595699310302734380f, -0.615231573581695560f, -0.634393274784088130f, + -0.653172850608825680f, -0.671558976173400880f, + -0.689540565013885500f, -0.707106769084930420f, -0.724247097969055180f, + -0.740951120853424070f, -0.757208824157714840f, -0.773010432720184330f, + -0.788346409797668460f, -0.803207516670227050f, + -0.817584812641143800f, -0.831469595432281490f, -0.844853579998016360f, + -0.857728600502014160f, -0.870086967945098880f, -0.881921291351318360f, + -0.893224298954010010f, -0.903989315032958980f, + -0.914209783077239990f, -0.923879504203796390f, -0.932992815971374510f, + -0.941544055938720700f, -0.949528157711029050f, -0.956940352916717530f, + -0.963776051998138430f, -0.970031261444091800f, + -0.975702106952667240f, -0.980785250663757320f, -0.985277652740478520f, + -0.989176511764526370f, -0.992479562759399410f, -0.995184719562530520f, + -0.997290432453155520f, -0.998795449733734130f, + -0.999698817729949950f, -1.000000000000000000f, -0.999698817729949950f, + -0.998795449733734130f, -0.997290432453155520f, -0.995184719562530520f, + -0.992479562759399410f, -0.989176511764526370f, + -0.985277652740478520f, -0.980785250663757320f, -0.975702106952667240f, + -0.970031261444091800f, -0.963776051998138430f, -0.956940352916717530f, + -0.949528157711029050f, -0.941544055938720700f, + -0.932992815971374510f, -0.923879504203796390f, -0.914209783077239990f, + -0.903989315032958980f, -0.893224298954010010f, -0.881921291351318360f, + -0.870086967945098880f, -0.857728600502014160f, + -0.844853579998016360f, -0.831469595432281490f, -0.817584812641143800f, + -0.803207516670227050f, -0.788346409797668460f, -0.773010432720184330f, + -0.757208824157714840f, -0.740951120853424070f, + -0.724247097969055180f, -0.707106769084930420f, -0.689540565013885500f, + -0.671558976173400880f, -0.653172850608825680f, -0.634393274784088130f, + -0.615231573581695560f, -0.595699310302734380f, + -0.575808167457580570f, -0.555570244789123540f, -0.534997642040252690f, + -0.514102756977081300f, -0.492898195981979370f, -0.471396744251251220f, + -0.449611335992813110f, -0.427555084228515630f, + -0.405241310596466060f, -0.382683426141738890f, -0.359895050525665280f, + -0.336889863014221190f, -0.313681751489639280f, -0.290284663438797000f, + -0.266712754964828490f, -0.242980182170867920f, + -0.219101235270500180f, -0.195090323686599730f, -0.170961886644363400f, + -0.146730467677116390f, -0.122410677373409270f, -0.098017141222953796f, + -0.073564566671848297f, -0.049067676067352295f, + -0.024541229009628296f, -0.000000000000000245f, 0.024541229009628296f +}; + + +/** + * @brief Fast approximation to the trigonometric sine function for floating-point data. + * @param[in] x input value in radians. + * @return sin(x). + */ + +float32_t arm_sin_f32( + float32_t x) +{ + float32_t sinVal, fract, in; /* Temporary variables for input, output */ + int32_t index; /* Index variable */ + uint32_t tableSize = (uint32_t) TABLE_SIZE; /* Initialise tablesize */ + float32_t wa, wb, wc, wd; /* Cubic interpolation coefficients */ + float32_t a, b, c, d; /* Four nearest output values */ + float32_t *tablePtr; /* Pointer to table */ + int32_t n; + float32_t fractsq, fractby2, fractby6, fractby3, fractsqby2; + float32_t oneminusfractby2; + float32_t frby2xfrsq, frby6xfrsq; + + /* input x is in radians */ + /* Scale the input to [0 1] range from [0 2*PI] , divide input by 2*pi */ + in = x * 0.159154943092f; + + /* Calculation of floor value of input */ + n = (int32_t) in; + + /* Make negative values towards -infinity */ + if(x < 0.0f) + { + n = n - 1; + } + + /* Map input value to [0 1] */ + in = in - (float32_t) n; + + /* Calculation of index of the table */ + index = (uint32_t) (tableSize * in); + + /* fractional value calculation */ + fract = ((float32_t) tableSize * in) - (float32_t) index; + + /* Checking min and max index of table */ + if(index < 0) + { + index = 0; + } + else if(index > 256) + { + index = 256; + } + + /* Initialise table pointer */ + tablePtr = (float32_t *) & sinTable[index]; + + /* Read four nearest values of input value from the sin table */ + a = tablePtr[0]; + b = tablePtr[1]; + c = tablePtr[2]; + d = tablePtr[3]; + + /* Cubic interpolation process */ + fractsq = fract * fract; + fractby2 = fract * 0.5f; + fractby6 = fract * 0.166666667f; + fractby3 = fract * 0.3333333333333f; + fractsqby2 = fractsq * 0.5f; + frby2xfrsq = (fractby2) * fractsq; + frby6xfrsq = (fractby6) * fractsq; + oneminusfractby2 = 1.0f - fractby2; + wb = fractsqby2 - fractby3; + wc = (fractsqby2 + fract); + wa = wb - frby6xfrsq; + wb = frby2xfrsq - fractsq; + sinVal = wa * a; + wc = wc - frby2xfrsq; + wd = (frby6xfrsq) - fractby6; + wb = wb + oneminusfractby2; + + /* Calculate sin value */ + sinVal = (sinVal + (b * wb)) + ((c * wc) + (d * wd)); + + /* Return the output value */ + return (sinVal); + +} + +/** + * @} end of sin group + */