test in progress
This commit is contained in:
Sheikah
164
Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_var_q15.c
Normal file
164
Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_var_q15.c
Normal file
@ -0,0 +1,164 @@
|
||||
/* ----------------------------------------------------------------------
|
||||
* Project: CMSIS DSP Library
|
||||
* Title: arm_var_q15.c
|
||||
* Description: Variance of an array of Q15 type
|
||||
*
|
||||
* $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
|
||||
*/
|
||||
|
||||
/**
|
||||
@addtogroup variance
|
||||
@{
|
||||
*/
|
||||
|
||||
/**
|
||||
@brief Variance of the elements of a Q15 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
|
||||
|
||||
@par Scaling and Overflow Behavior
|
||||
The function is implemented using a 64-bit internal accumulator.
|
||||
The input is represented in 1.15 format.
|
||||
Intermediate multiplication yields a 2.30 format, and this
|
||||
result is added without saturation to a 64-bit accumulator in 34.30 format.
|
||||
With 33 guard bits in the accumulator, there is no risk of overflow, and the
|
||||
full precision of the intermediate multiplication is preserved.
|
||||
Finally, the 34.30 result is truncated to 34.15 format by discarding the lower
|
||||
15 bits, and then saturated to yield a result in 1.15 format.
|
||||
*/
|
||||
|
||||
void arm_var_q15(
|
||||
const q15_t * pSrc,
|
||||
uint32_t blockSize,
|
||||
q15_t * pResult)
|
||||
{
|
||||
uint32_t blkCnt; /* Loop counter */
|
||||
q31_t sum = 0; /* Accumulator */
|
||||
q31_t meanOfSquares, squareOfMean; /* Square of mean and mean of square */
|
||||
q63_t sumOfSquares = 0; /* Sum of squares */
|
||||
q15_t in; /* Temporary variable to store input value */
|
||||
|
||||
#if defined (ARM_MATH_LOOPUNROLL) && defined (ARM_MATH_DSP)
|
||||
q31_t in32; /* Temporary variable to store input value */
|
||||
#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] */
|
||||
|
||||
/* Compute sum of squares and store result in a temporary variable, sumOfSquares. */
|
||||
/* Compute sum and store result in a temporary variable, sum. */
|
||||
#if defined (ARM_MATH_DSP)
|
||||
in32 = read_q15x2_ia ((q15_t **) &pSrc);
|
||||
sumOfSquares = __SMLALD(in32, in32, sumOfSquares);
|
||||
sum += ((in32 << 16U) >> 16U);
|
||||
sum += (in32 >> 16U);
|
||||
|
||||
in32 = read_q15x2_ia ((q15_t **) &pSrc);
|
||||
sumOfSquares = __SMLALD(in32, in32, sumOfSquares);
|
||||
sum += ((in32 << 16U) >> 16U);
|
||||
sum += (in32 >> 16U);
|
||||
#else
|
||||
in = *pSrc++;
|
||||
sumOfSquares += (in * in);
|
||||
sum += in;
|
||||
|
||||
in = *pSrc++;
|
||||
sumOfSquares += (in * in);
|
||||
sum += in;
|
||||
|
||||
in = *pSrc++;
|
||||
sumOfSquares += (in * in);
|
||||
sum += in;
|
||||
|
||||
in = *pSrc++;
|
||||
sumOfSquares += (in * in);
|
||||
sum += in;
|
||||
#endif /* #if defined (ARM_MATH_DSP) */
|
||||
|
||||
/* 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. */
|
||||
#if defined (ARM_MATH_DSP)
|
||||
sumOfSquares = __SMLALD(in, in, sumOfSquares);
|
||||
#else
|
||||
sumOfSquares += (in * in);
|
||||
#endif /* #if defined (ARM_MATH_DSP) */
|
||||
/* Compute sum and store result in a temporary variable, sum. */
|
||||
sum += in;
|
||||
|
||||
/* Decrement loop counter */
|
||||
blkCnt--;
|
||||
}
|
||||
|
||||
/* Compute Mean of squares and store result in a temporary variable, meanOfSquares. */
|
||||
meanOfSquares = (q31_t) (sumOfSquares / (q63_t)(blockSize - 1U));
|
||||
|
||||
/* Compute square of mean */
|
||||
squareOfMean = (q31_t) ((q63_t) sum * sum / (q63_t)(blockSize * (blockSize - 1U)));
|
||||
|
||||
/* mean of squares minus the square of mean. */
|
||||
*pResult = (meanOfSquares - squareOfMean) >> 15U;
|
||||
}
|
||||
|
||||
/**
|
||||
@} end of variance group
|
||||
*/
|
||||
Reference in New Issue
Block a user