test in progress
This commit is contained in:
234
Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_var_f32.c
Normal file
234
Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_var_f32.c
Normal file
@ -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:
|
||||
|
||||
<pre>
|
||||
Result = sum(element - meanOfElements)^2) / numElement - 1
|
||||
|
||||
meanOfElements = ( pSrc[0] * pSrc[0] + pSrc[1] * pSrc[1] + ... + pSrc[blockSize-1] ) / blockSize
|
||||
</pre>
|
||||
|
||||
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
|
||||
*/
|
Reference in New Issue
Block a user