From 86608c6770cf08c138a2bdab5855072f64be09ef Mon Sep 17 00:00:00 2001 From: joshua Date: Sat, 30 Dec 2023 23:54:31 -0500 Subject: initial commit --- .../DSP/Source/StatisticsFunctions/arm_std_f32.c | 188 +++++++++++++++++++++ 1 file changed, 188 insertions(+) create mode 100644 Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_std_f32.c (limited to 'Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_std_f32.c') diff --git a/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_std_f32.c b/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_std_f32.c new file mode 100644 index 0000000..214a794 --- /dev/null +++ b/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_std_f32.c @@ -0,0 +1,188 @@ +/* ---------------------------------------------------------------------- + * Project: CMSIS DSP Library + * Title: arm_std_f32.c + * Description: Standard deviation of the elements of a floating-point vector + * + * $Date: 18. March 2019 + * $Revision: V1.6.0 + * + * Target Processor: Cortex-M cores + * -------------------------------------------------------------------- */ +/* + * Copyright (C) 2010-2019 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 "arm_math.h" + +/** + @ingroup groupStats + */ + +/** + @defgroup STD Standard deviation + + Calculates the standard deviation of the elements in the input vector. + The underlying algorithm is used: + + 
+      Result = sqrt((sumOfSquares - sum2 / blockSize) / (blockSize - 1))
+
+      sumOfSquares = pSrc[0] * pSrc[0] + pSrc[1] * pSrc[1] + ... + pSrc[blockSize-1] * pSrc[blockSize-1]
+      sum = pSrc[0] + pSrc[1] + pSrc[2] + ... + pSrc[blockSize-1]
+
+ + There are separate functions for floating point, Q31, and Q15 data types. + */ + +/** + @addtogroup STD + @{ + */ + +/** + @brief Standard deviation of the elements of a floating-point vector. + @param[in] pSrc points to the input vector + @param[in] blockSize number of samples in input vector + @param[out] pResult standard deviation value returned here + @return none + */ +#if defined(ARM_MATH_NEON_EXPERIMENTAL) +void arm_std_f32( + const float32_t * pSrc, + uint32_t blockSize, + float32_t * pResult) +{ + float32_t var; + arm_var_f32(pSrc,blockSize,&var); + arm_sqrt_f32(var, pResult); +} +#else +void arm_std_f32( + const float32_t * pSrc, + uint32_t blockSize, + float32_t * pResult) +{ + uint32_t blkCnt; /* Loop counter */ + float32_t sum = 0.0f; /* Temporary result storage */ + float32_t sumOfSquares = 0.0f; /* Sum of squares */ + float32_t in; /* Temporary variable to store input value */ + +#ifndef ARM_MATH_CM0_FAMILY + float32_t meanOfSquares, mean, squareOfMean; /* Temporary variables */ +#else + float32_t squareOfSum; /* Square of Sum */ + float32_t var; /* Temporary varaince storage */ +#endif + + if (blockSize <= 1U) + { + *pResult = 0; + return; + } + +#if defined (ARM_MATH_LOOPUNROLL) + + /* Loop unrolling: Compute 4 outputs at a time */ + blkCnt = blockSize >> 2U; + + while (blkCnt > 0U) + { + /* C = A[0] * A[0] + A[1] * A[1] + ... + A[blockSize-1] * A[blockSize-1] */ + /* C = A[0] + A[1] + ... + A[blockSize-1] */ + + in = *pSrc++; + /* Compute sum of squares and store result in a temporary variable, sumOfSquares. */ + sumOfSquares += in * in; + /* Compute sum and store result in a temporary variable, sum. */ + sum += in; + + in = *pSrc++; + sumOfSquares += in * in; + sum += in; + + in = *pSrc++; + sumOfSquares += in * in; + sum += in; + + in = *pSrc++; + sumOfSquares += in * in; + sum += in; + + /* Decrement loop counter */ + blkCnt--; + } + + /* Loop unrolling: Compute remaining outputs */ + blkCnt = blockSize % 0x4U; + +#else + + /* Initialize blkCnt with number of samples */ + blkCnt = blockSize; + +#endif /* #if defined (ARM_MATH_LOOPUNROLL) */ + + while (blkCnt > 0U) + { + /* C = A[0] * A[0] + A[1] * A[1] + ... + A[blockSize-1] * A[blockSize-1] */ + /* C = A[0] + A[1] + ... + A[blockSize-1] */ + + in = *pSrc++; + /* Compute sum of squares and store result in a temporary variable, sumOfSquares. */ + sumOfSquares += ( in * in); + /* Compute sum and store result in a temporary variable, sum. */ + sum += in; + + /* Decrement loop counter */ + blkCnt--; + } + +#ifndef ARM_MATH_CM0_FAMILY + + /* Compute Mean of squares and store result in a temporary variable, meanOfSquares. */ + meanOfSquares = sumOfSquares / ((float32_t) blockSize - 1.0f); + + /* Compute mean of all input values */ + mean = sum / (float32_t) blockSize; + + /* Compute square of mean */ + squareOfMean = (mean * mean) * (((float32_t) blockSize) / + ((float32_t) blockSize - 1.0f)); + + /* Compute standard deviation and store result to destination */ + arm_sqrt_f32((meanOfSquares - squareOfMean), pResult); + +#else + /* Run the below code for Cortex-M0 */ + + /* Compute square of sum */ + squareOfSum = ((sum * sum) / (float32_t) blockSize); + + /* Compute variance */ + var = ((sumOfSquares - squareOfSum) / (float32_t) (blockSize - 1.0f)); + + /* Compute standard deviation and store result in destination */ + arm_sqrt_f32(var, pResult); + +#endif /* #ifndef ARM_MATH_CM0_FAMILY */ + +} +#endif /* #if defined(ARM_MATH_NEON) */ + +/** + @} end of STD group + */ -- cgit v1.2.3