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Diffstat (limited to 'DSP_Lib/Source/StatisticsFunctions/arm_var_q31.c')
| -rw-r--r-- | DSP_Lib/Source/StatisticsFunctions/arm_var_q31.c | 187 |
1 files changed, 0 insertions, 187 deletions
diff --git a/DSP_Lib/Source/StatisticsFunctions/arm_var_q31.c b/DSP_Lib/Source/StatisticsFunctions/arm_var_q31.c deleted file mode 100644 index 6b9e228..0000000 --- a/DSP_Lib/Source/StatisticsFunctions/arm_var_q31.c +++ /dev/null @@ -1,187 +0,0 @@ -/* ---------------------------------------------------------------------- -* Copyright (C) 2010-2014 ARM Limited. All rights reserved. -* -* $Date: 19. March 2015 -* $Revision: V.1.4.5 -* -* Project: CMSIS DSP Library -* Title: arm_var_q31.c -* -* Description: Variance of an array of Q31 type. -* -* 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 groupStats - */ - -/** - * @addtogroup variance - * @{ - */ - -/** - * @brief Variance of the elements of a Q31 vector. - * @param[in] *pSrc points to the input vector - * @param[in] blockSize length of the input vector - * @param[out] *pResult variance value returned here - * @return none. - * - * @details - * <b>Scaling and Overflow Behavior:</b> - * - *\par - * The function is implemented using an internal 64-bit accumulator. - * The input is represented in 1.31 format, which is then downshifted by 8 bits - * which yields 1.23, and intermediate multiplication yields a 2.46 format. - * The accumulator maintains full precision of the intermediate multiplication results, - * but provides only a 16 guard bits. - * There is no saturation on intermediate additions. - * If the accumulator overflows it wraps around and distorts the result. - * In order to avoid overflows completely the input signal must be scaled down by - * log2(blockSize)-8 bits, as a total of blockSize additions are performed internally. - * After division, internal variables should be Q18.46 - * Finally, the 18.46 accumulator is right shifted by 15 bits to yield a 1.31 format value. - * - */ - - -void arm_var_q31( - q31_t * pSrc, - uint32_t blockSize, - q31_t * pResult) -{ - q63_t sum = 0; /* Accumulator */ - q63_t meanOfSquares, squareOfMean; /* square of mean and mean of square */ - q31_t in; /* input value */ - uint32_t blkCnt; /* loop counter */ - q63_t sumOfSquares = 0; /* Accumulator */ - - if(blockSize == 1) - { - *pResult = 0; - return; - } - -#ifndef ARM_MATH_CM0_FAMILY - - /* Run the below code for Cortex-M4 and Cortex-M3 */ - - /*loop Unrolling */ - blkCnt = blockSize >> 2u; - - /* First part of the processing with loop unrolling. Compute 4 outputs at a time. - ** a second loop below computes the remaining 1 to 3 samples. */ - while(blkCnt > 0u) - { - /* C = (A[0] * A[0] + A[1] * A[1] + ... + A[blockSize-1] * A[blockSize-1]) */ - /* Compute Sum of squares of the input samples - * and then store the result in a temporary variable, sum. */ - in = *pSrc++ >> 8; - sum += in; - sumOfSquares += ((q63_t) (in) * (in)); - in = *pSrc++ >> 8; - sum += in; - sumOfSquares += ((q63_t) (in) * (in)); - in = *pSrc++ >> 8; - sum += in; - sumOfSquares += ((q63_t) (in) * (in)); - in = *pSrc++ >> 8; - sum += in; - sumOfSquares += ((q63_t) (in) * (in)); - - /* Decrement the loop counter */ - blkCnt--; - } - - /* If the blockSize is not a multiple of 4, compute any remaining output samples here. - ** No loop unrolling is used. */ - blkCnt = blockSize % 0x4u; - - while(blkCnt > 0u) - { - /* C = (A[0] * A[0] + A[1] * A[1] + ... + A[blockSize-1] * A[blockSize-1]) */ - /* Compute Sum of squares of the input samples - * and then store the result in a temporary variable, sum. */ - in = *pSrc++ >> 8; - sum += in; - sumOfSquares += ((q63_t) (in) * (in)); - - /* Decrement the loop counter */ - blkCnt--; - } - - /* Compute Mean of squares of the input samples - * and then store the result in a temporary variable, meanOfSquares. */ - meanOfSquares = sumOfSquares / (q63_t)(blockSize - 1); - -#else - - /* Run the below code for Cortex-M0 */ - - /* Loop over blockSize number of values */ - blkCnt = blockSize; - - while(blkCnt > 0u) - { - /* C = (A[0] * A[0] + A[1] * A[1] + ... + A[blockSize-1] * A[blockSize-1]) */ - /* Compute Sum of squares of the input samples - * and then store the result in a temporary variable, sumOfSquares. */ - in = *pSrc++ >> 8; - sumOfSquares += ((q63_t) (in) * (in)); - - /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) */ - /* Compute sum of all input values and then store the result in a temporary variable, sum. */ - sum += in; - - /* Decrement the loop counter */ - blkCnt--; - } - - /* Compute Mean of squares of the input samples - * and then store the result in a temporary variable, meanOfSquares. */ - meanOfSquares = sumOfSquares / (q63_t)(blockSize - 1); - -#endif /* #ifndef ARM_MATH_CM0_FAMILY */ - - /* Compute square of mean */ - squareOfMean = sum * sum / (q63_t)(blockSize * (blockSize - 1u)); - - - /* Compute standard deviation and then store the result to the destination */ - *pResult = (meanOfSquares - squareOfMean) >> 15; - -} - -/** - * @} end of variance group - */ |