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Diffstat (limited to 'tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FastMathFunctions/arm_cos_f32.c')
-rw-r--r-- | tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FastMathFunctions/arm_cos_f32.c | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FastMathFunctions/arm_cos_f32.c b/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FastMathFunctions/arm_cos_f32.c new file mode 100644 index 0000000000..20a9f3657b --- /dev/null +++ b/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FastMathFunctions/arm_cos_f32.c @@ -0,0 +1,290 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010-2013 ARM Limited. All rights reserved. +* +* $Date: 17. January 2013 +* $Revision: V1.4.1 +* +* Project: CMSIS DSP Library +* Title: arm_cos_f32.c +* +* Description: Fast cosine calculation for floating-point values. +* +* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 +* +* Redistribution and use in source and binary forms, with or without +* modification, are permitted provided that the following conditions +* are met: +* - Redistributions of source code must retain the above copyright +* notice, this list of conditions and the following disclaimer. +* - Redistributions in binary form must reproduce the above copyright +* notice, this list of conditions and the following disclaimer in +* the documentation and/or other materials provided with the +* distribution. +* - Neither the name of ARM LIMITED nor the names of its contributors +* may be used to endorse or promote products derived from this +* software without specific prior written permission. +* +* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS +* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE +* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, +* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, +* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN +* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +* POSSIBILITY OF SUCH DAMAGE. +* -------------------------------------------------------------------- */ + +#include "arm_math.h" +/** + * @ingroup groupFastMath + */ + +/** + * @defgroup cos Cosine + * + * Computes the trigonometric cosine 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). The fixed-point range is chosen so that a + * value of 2*pi wraps around to 0. + * + * 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 cos + * @{ + */ + + +/** +* \par +* <b>Example code for Generation of Cos Table:</b> +* <pre> +* tableSize = 256; +* for(n = -1; n < (tableSize + 2); n++) +* { +* cosTable[n+1]= cos(2*pi*n/tableSize); +* } </pre> +* where pi value is 3.14159265358979 +*/ + +static const float32_t cosTable[260] = { + 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, 0.000000000000000061f, -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, -0.000000000000000184f, 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 +}; + +/** + * @brief Fast approximation to the trigonometric cosine function for floating-point data. + * @param[in] x input value in radians. + * @return cos(x). + */ + + +float32_t arm_cos_f32( + float32_t x) +{ + float32_t cosVal, fract, in; + int32_t index; + uint32_t tableSize = (uint32_t) TABLE_SIZE; + float32_t wa, wb, wc, wd; + float32_t a, b, c, d; + float32_t *tablePtr; + 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 *) & cosTable[index]; + + /* Read four nearest values of input value from the cos 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; + cosVal = wa * a; + wc = wc - frby2xfrsq; + wd = (frby6xfrsq) - fractby6; + wb = wb + oneminusfractby2; + + /* Calculate cos value */ + cosVal = (cosVal + (b * wb)) + ((c * wc) + (d * wd)); + + /* Return the output value */ + return (cosVal); + +} + +/** + * @} end of cos group + */ |