mbed official / mbed-dsp

CMSIS DSP library

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cmsis_dsp/StatisticsFunctions/arm_mean_f32.c@3:7a284390b0ce, 2013-11-08 (annotated)

Committer:
mbed_official
Date:
Fri Nov 08 13:45:10 2013 +0000
Revision:
3:7a284390b0ce
Parent:
2:da51fb522205 
Synchronized with git revision e69956aba2f68a2a26ac26b051f8d349deaa1ce8

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emilmont 1:fdd22bb7aa52 1 /* ----------------------------------------------------------------------
mbed_official 3:7a284390b0ce 2 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
emilmont 1:fdd22bb7aa52 3 *
mbed_official 3:7a284390b0ce 4 * $Date: 17. January 2013
mbed_official 3:7a284390b0ce 5 * $Revision: V1.4.1
emilmont 1:fdd22bb7aa52 6 *
emilmont 2:da51fb522205 7 * Project: CMSIS DSP Library
emilmont 2:da51fb522205 8 * Title: arm_mean_f32.c
emilmont 1:fdd22bb7aa52 9 *
emilmont 2:da51fb522205 10 * Description: Mean value of a floating-point vector.
emilmont 1:fdd22bb7aa52 11 *
emilmont 1:fdd22bb7aa52 12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
emilmont 1:fdd22bb7aa52 13 *
mbed_official 3:7a284390b0ce 14 * Redistribution and use in source and binary forms, with or without
mbed_official 3:7a284390b0ce 15 * modification, are permitted provided that the following conditions
mbed_official 3:7a284390b0ce 16 * are met:
mbed_official 3:7a284390b0ce 17 * - Redistributions of source code must retain the above copyright
mbed_official 3:7a284390b0ce 18 * notice, this list of conditions and the following disclaimer.
mbed_official 3:7a284390b0ce 19 * - Redistributions in binary form must reproduce the above copyright
mbed_official 3:7a284390b0ce 20 * notice, this list of conditions and the following disclaimer in
mbed_official 3:7a284390b0ce 21 * the documentation and/or other materials provided with the
mbed_official 3:7a284390b0ce 22 * distribution.
mbed_official 3:7a284390b0ce 23 * - Neither the name of ARM LIMITED nor the names of its contributors
mbed_official 3:7a284390b0ce 24 * may be used to endorse or promote products derived from this
mbed_official 3:7a284390b0ce 25 * software without specific prior written permission.
mbed_official 3:7a284390b0ce 26 *
mbed_official 3:7a284390b0ce 27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
mbed_official 3:7a284390b0ce 28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
mbed_official 3:7a284390b0ce 29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
mbed_official 3:7a284390b0ce 30 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
mbed_official 3:7a284390b0ce 31 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
mbed_official 3:7a284390b0ce 32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
mbed_official 3:7a284390b0ce 33 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
mbed_official 3:7a284390b0ce 34 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
mbed_official 3:7a284390b0ce 35 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
mbed_official 3:7a284390b0ce 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
mbed_official 3:7a284390b0ce 37 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
mbed_official 3:7a284390b0ce 38 * POSSIBILITY OF SUCH DAMAGE.
emilmont 1:fdd22bb7aa52 39 * ---------------------------------------------------------------------------- */
emilmont 1:fdd22bb7aa52 40
emilmont 1:fdd22bb7aa52 41 #include "arm_math.h"
emilmont 1:fdd22bb7aa52 42
emilmont 1:fdd22bb7aa52 43 /**
emilmont 1:fdd22bb7aa52 44 * @ingroup groupStats
emilmont 1:fdd22bb7aa52 45 */
emilmont 1:fdd22bb7aa52 46
emilmont 1:fdd22bb7aa52 47 /**
emilmont 1:fdd22bb7aa52 48 * @defgroup mean Mean
emilmont 1:fdd22bb7aa52 49 *
emilmont 1:fdd22bb7aa52 50 * Calculates the mean of the input vector. Mean is defined as the average of the elements in the vector.
emilmont 1:fdd22bb7aa52 51 * The underlying algorithm is used:
emilmont 1:fdd22bb7aa52 52 *
emilmont 1:fdd22bb7aa52 53 * <pre>
emilmont 2:da51fb522205 54 * Result = (pSrc[0] + pSrc[1] + pSrc[2] + ... + pSrc[blockSize-1]) / blockSize;
emilmont 1:fdd22bb7aa52 55 * </pre>
emilmont 1:fdd22bb7aa52 56 *
emilmont 1:fdd22bb7aa52 57 * There are separate functions for floating-point, Q31, Q15, and Q7 data types.
emilmont 1:fdd22bb7aa52 58 */
emilmont 1:fdd22bb7aa52 59
emilmont 1:fdd22bb7aa52 60 /**
emilmont 1:fdd22bb7aa52 61 * @addtogroup mean
emilmont 1:fdd22bb7aa52 62 * @{
emilmont 1:fdd22bb7aa52 63 */
emilmont 1:fdd22bb7aa52 64
emilmont 1:fdd22bb7aa52 65
emilmont 1:fdd22bb7aa52 66 /**
emilmont 1:fdd22bb7aa52 67 * @brief Mean value of a floating-point vector.
emilmont 1:fdd22bb7aa52 68 * @param[in] *pSrc points to the input vector
emilmont 1:fdd22bb7aa52 69 * @param[in] blockSize length of the input vector
emilmont 1:fdd22bb7aa52 70 * @param[out] *pResult mean value returned here
emilmont 1:fdd22bb7aa52 71 * @return none.
emilmont 1:fdd22bb7aa52 72 */
emilmont 1:fdd22bb7aa52 73
emilmont 1:fdd22bb7aa52 74
emilmont 1:fdd22bb7aa52 75 void arm_mean_f32(
emilmont 1:fdd22bb7aa52 76 float32_t * pSrc,
emilmont 1:fdd22bb7aa52 77 uint32_t blockSize,
emilmont 1:fdd22bb7aa52 78 float32_t * pResult)
emilmont 1:fdd22bb7aa52 79 {
emilmont 1:fdd22bb7aa52 80 float32_t sum = 0.0f; /* Temporary result storage */
emilmont 1:fdd22bb7aa52 81 uint32_t blkCnt; /* loop counter */
emilmont 1:fdd22bb7aa52 82
mbed_official 3:7a284390b0ce 83 #ifndef ARM_MATH_CM0_FAMILY
emilmont 1:fdd22bb7aa52 84
emilmont 1:fdd22bb7aa52 85 /* Run the below code for Cortex-M4 and Cortex-M3 */
emilmont 1:fdd22bb7aa52 86 float32_t in1, in2, in3, in4;
emilmont 1:fdd22bb7aa52 87
emilmont 1:fdd22bb7aa52 88 /*loop Unrolling */
emilmont 1:fdd22bb7aa52 89 blkCnt = blockSize >> 2u;
emilmont 1:fdd22bb7aa52 90
emilmont 1:fdd22bb7aa52 91 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
emilmont 1:fdd22bb7aa52 92 ** a second loop below computes the remaining 1 to 3 samples. */
emilmont 1:fdd22bb7aa52 93 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 94 {
emilmont 1:fdd22bb7aa52 95 /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) */
emilmont 1:fdd22bb7aa52 96 in1 = *pSrc++;
emilmont 1:fdd22bb7aa52 97 in2 = *pSrc++;
emilmont 1:fdd22bb7aa52 98 in3 = *pSrc++;
emilmont 1:fdd22bb7aa52 99 in4 = *pSrc++;
emilmont 1:fdd22bb7aa52 100
emilmont 1:fdd22bb7aa52 101 sum += in1;
emilmont 1:fdd22bb7aa52 102 sum += in2;
emilmont 1:fdd22bb7aa52 103 sum += in3;
emilmont 1:fdd22bb7aa52 104 sum += in4;
emilmont 1:fdd22bb7aa52 105
emilmont 1:fdd22bb7aa52 106 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 107 blkCnt--;
emilmont 1:fdd22bb7aa52 108 }
emilmont 1:fdd22bb7aa52 109
emilmont 1:fdd22bb7aa52 110 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
emilmont 1:fdd22bb7aa52 111 ** No loop unrolling is used. */
emilmont 1:fdd22bb7aa52 112 blkCnt = blockSize % 0x4u;
emilmont 1:fdd22bb7aa52 113
emilmont 1:fdd22bb7aa52 114 #else
emilmont 1:fdd22bb7aa52 115
emilmont 1:fdd22bb7aa52 116 /* Run the below code for Cortex-M0 */
emilmont 1:fdd22bb7aa52 117
emilmont 1:fdd22bb7aa52 118 /* Loop over blockSize number of values */
emilmont 1:fdd22bb7aa52 119 blkCnt = blockSize;
emilmont 1:fdd22bb7aa52 120
mbed_official 3:7a284390b0ce 121 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
emilmont 1:fdd22bb7aa52 122
emilmont 1:fdd22bb7aa52 123 while(blkCnt > 0u)
emilmont 1:fdd22bb7aa52 124 {
emilmont 1:fdd22bb7aa52 125 /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) */
emilmont 1:fdd22bb7aa52 126 sum += *pSrc++;
emilmont 1:fdd22bb7aa52 127
emilmont 1:fdd22bb7aa52 128 /* Decrement the loop counter */
emilmont 1:fdd22bb7aa52 129 blkCnt--;
emilmont 1:fdd22bb7aa52 130 }
emilmont 1:fdd22bb7aa52 131
emilmont 1:fdd22bb7aa52 132 /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) / blockSize */
emilmont 1:fdd22bb7aa52 133 /* Store the result to the destination */
emilmont 1:fdd22bb7aa52 134 *pResult = sum / (float32_t) blockSize;
emilmont 1:fdd22bb7aa52 135 }
emilmont 1:fdd22bb7aa52 136
emilmont 1:fdd22bb7aa52 137 /**
emilmont 1:fdd22bb7aa52 138 * @} end of mean group
emilmont 1:fdd22bb7aa52 139 */