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_var_f32.c | 234 +++++++++++++++++++++ 1 file changed, 234 insertions(+) create mode 100644 Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_var_f32.c (limited to 'Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_var_f32.c') diff --git a/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_var_f32.c b/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_var_f32.c new file mode 100644 index 0000000..18f5806 --- /dev/null +++ b/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_var_f32.c @@ -0,0 +1,234 @@ +/* ---------------------------------------------------------------------- + * Project: CMSIS DSP Library + * Title: arm_var_f32.c + * Description: Variance 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 variance Variance + + Calculates the variance of the elements in the input vector. + The underlying algorithm used is the direct method sometimes referred to as the two-pass method: + + 
+      Result = sum(element - meanOfElements)^2) / numElement - 1
+
+      meanOfElements = ( pSrc[0] * pSrc[0] + pSrc[1] * pSrc[1] + ... + pSrc[blockSize-1] ) / blockSize
+
+ + There are separate functions for floating point, Q31, and Q15 data types. + */ + +/** + @addtogroup variance + @{ + */ + +/** + @brief Variance 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 variance value returned here + @return none + */ +#if defined(ARM_MATH_NEON_EXPERIMENTAL) +void arm_var_f32( + const float32_t * pSrc, + uint32_t blockSize, + float32_t * pResult) +{ + float32_t mean; + + float32_t sum = 0.0f; /* accumulator */ + float32_t in; /* Temporary variable to store input value */ + uint32_t blkCnt; /* loop counter */ + + float32x4_t sumV = vdupq_n_f32(0.0f); /* Temporary result storage */ + float32x2_t sumV2; + float32x4_t inV; + float32x4_t avg; + + arm_mean_f32(pSrc,blockSize,&mean); + avg = vdupq_n_f32(mean); + + blkCnt = blockSize >> 2U; + + /* 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[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */ + /* Compute Power and then store the result in a temporary variable, sum. */ + inV = vld1q_f32(pSrc); + inV = vsubq_f32(inV, avg); + sumV = vmlaq_f32(sumV, inV, inV); + pSrc += 4; + + /* Decrement the loop counter */ + blkCnt--; + } + + sumV2 = vpadd_f32(vget_low_f32(sumV),vget_high_f32(sumV)); + sum = sumV2[0] + sumV2[1]; + + /* 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[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */ + /* compute power and then store the result in a temporary variable, sum. */ + in = *pSrc++; + in = in - mean; + sum += in * in; + + /* Decrement the loop counter */ + blkCnt--; + } + + /* Variance */ + *pResult = sum / (float32_t)(blockSize - 1.0f); + +} + +#else +void arm_var_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 fSum = 0.0f; + float32_t fMean, fValue; + const float32_t * pInput = pSrc; + + 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[1] + A[2] + ... + A[blockSize-1]) */ + + sum += *pInput++; + sum += *pInput++; + sum += *pInput++; + sum += *pInput++; + + + /* 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[1] + A[2] + ... + A[blockSize-1]) */ + + sum += *pInput++; + + /* Decrement loop counter */ + blkCnt--; + } + + /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) / blockSize */ + fMean = sum / (float32_t) blockSize; + + pInput = pSrc; + +#if defined (ARM_MATH_LOOPUNROLL) + + /* Loop unrolling: Compute 4 outputs at a time */ + blkCnt = blockSize >> 2U; + + while (blkCnt > 0U) + { + fValue = *pInput++ - fMean; + fSum += fValue * fValue; + + fValue = *pInput++ - fMean; + fSum += fValue * fValue; + + fValue = *pInput++ - fMean; + fSum += fValue * fValue; + + fValue = *pInput++ - fMean; + fSum += fValue * fValue; + + /* 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) + { + fValue = *pInput++ - fMean; + fSum += fValue * fValue; + + /* Decrement loop counter */ + blkCnt--; + } + + /* Variance */ + *pResult = fSum / (float32_t)(blockSize - 1.0f); +} +#endif /* #if defined(ARM_MATH_NEON) */ + +/** + @} end of variance group + */ -- cgit v1.2.3