V4.0.1 of the ARM CMSIS DSP libraries. Note that arm_bitreversal2.s, arm_cfft_f32.c and arm_rfft_fast_f32.c had to be removed. arm_bitreversal2.s will not assemble with the online tools. So, the fast f32 FFT functions are not yet available. All the other FFT functions are available.
Dependents: MPU9150_Example fir_f32 fir_f32 MPU9150_nucleo_noni2cdev ... more
StatisticsFunctions/arm_std_q31.c@0:3d9c67d97d6f, 2014-07-28 (annotated)
- Committer:
- emh203
- Date:
- Mon Jul 28 15:03:15 2014 +0000
- Revision:
- 0:3d9c67d97d6f
1st working commit. Had to remove arm_bitreversal2.s arm_cfft_f32.c and arm_rfft_fast_f32.c. The .s will not assemble. For now I removed these functions so we could at least have a library for the other functions.
Who changed what in which revision?
User | Revision | Line number | New contents of line |
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emh203 | 0:3d9c67d97d6f | 1 | /* ---------------------------------------------------------------------- |
emh203 | 0:3d9c67d97d6f | 2 | * Copyright (C) 2010-2014 ARM Limited. All rights reserved. |
emh203 | 0:3d9c67d97d6f | 3 | * |
emh203 | 0:3d9c67d97d6f | 4 | * $Date: 12. March 2014 |
emh203 | 0:3d9c67d97d6f | 5 | * $Revision: V1.4.3 |
emh203 | 0:3d9c67d97d6f | 6 | * |
emh203 | 0:3d9c67d97d6f | 7 | * Project: CMSIS DSP Library |
emh203 | 0:3d9c67d97d6f | 8 | * Title: arm_std_q31.c |
emh203 | 0:3d9c67d97d6f | 9 | * |
emh203 | 0:3d9c67d97d6f | 10 | * Description: Standard deviation of an array of Q31 type. |
emh203 | 0:3d9c67d97d6f | 11 | * |
emh203 | 0:3d9c67d97d6f | 12 | * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 |
emh203 | 0:3d9c67d97d6f | 13 | * |
emh203 | 0:3d9c67d97d6f | 14 | * Redistribution and use in source and binary forms, with or without |
emh203 | 0:3d9c67d97d6f | 15 | * modification, are permitted provided that the following conditions |
emh203 | 0:3d9c67d97d6f | 16 | * are met: |
emh203 | 0:3d9c67d97d6f | 17 | * - Redistributions of source code must retain the above copyright |
emh203 | 0:3d9c67d97d6f | 18 | * notice, this list of conditions and the following disclaimer. |
emh203 | 0:3d9c67d97d6f | 19 | * - Redistributions in binary form must reproduce the above copyright |
emh203 | 0:3d9c67d97d6f | 20 | * notice, this list of conditions and the following disclaimer in |
emh203 | 0:3d9c67d97d6f | 21 | * the documentation and/or other materials provided with the |
emh203 | 0:3d9c67d97d6f | 22 | * distribution. |
emh203 | 0:3d9c67d97d6f | 23 | * - Neither the name of ARM LIMITED nor the names of its contributors |
emh203 | 0:3d9c67d97d6f | 24 | * may be used to endorse or promote products derived from this |
emh203 | 0:3d9c67d97d6f | 25 | * software without specific prior written permission. |
emh203 | 0:3d9c67d97d6f | 26 | * |
emh203 | 0:3d9c67d97d6f | 27 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
emh203 | 0:3d9c67d97d6f | 28 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
emh203 | 0:3d9c67d97d6f | 29 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
emh203 | 0:3d9c67d97d6f | 30 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
emh203 | 0:3d9c67d97d6f | 31 | * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
emh203 | 0:3d9c67d97d6f | 32 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
emh203 | 0:3d9c67d97d6f | 33 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
emh203 | 0:3d9c67d97d6f | 34 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
emh203 | 0:3d9c67d97d6f | 35 | * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
emh203 | 0:3d9c67d97d6f | 36 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
emh203 | 0:3d9c67d97d6f | 37 | * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
emh203 | 0:3d9c67d97d6f | 38 | * POSSIBILITY OF SUCH DAMAGE. |
emh203 | 0:3d9c67d97d6f | 39 | * -------------------------------------------------------------------- */ |
emh203 | 0:3d9c67d97d6f | 40 | |
emh203 | 0:3d9c67d97d6f | 41 | #include "arm_math.h" |
emh203 | 0:3d9c67d97d6f | 42 | |
emh203 | 0:3d9c67d97d6f | 43 | /** |
emh203 | 0:3d9c67d97d6f | 44 | * @ingroup groupStats |
emh203 | 0:3d9c67d97d6f | 45 | */ |
emh203 | 0:3d9c67d97d6f | 46 | |
emh203 | 0:3d9c67d97d6f | 47 | /** |
emh203 | 0:3d9c67d97d6f | 48 | * @addtogroup STD |
emh203 | 0:3d9c67d97d6f | 49 | * @{ |
emh203 | 0:3d9c67d97d6f | 50 | */ |
emh203 | 0:3d9c67d97d6f | 51 | |
emh203 | 0:3d9c67d97d6f | 52 | |
emh203 | 0:3d9c67d97d6f | 53 | /** |
emh203 | 0:3d9c67d97d6f | 54 | * @brief Standard deviation of the elements of a Q31 vector. |
emh203 | 0:3d9c67d97d6f | 55 | * @param[in] *pSrc points to the input vector |
emh203 | 0:3d9c67d97d6f | 56 | * @param[in] blockSize length of the input vector |
emh203 | 0:3d9c67d97d6f | 57 | * @param[out] *pResult standard deviation value returned here |
emh203 | 0:3d9c67d97d6f | 58 | * @return none. |
emh203 | 0:3d9c67d97d6f | 59 | * @details |
emh203 | 0:3d9c67d97d6f | 60 | * <b>Scaling and Overflow Behavior:</b> |
emh203 | 0:3d9c67d97d6f | 61 | * |
emh203 | 0:3d9c67d97d6f | 62 | *\par |
emh203 | 0:3d9c67d97d6f | 63 | * The function is implemented using an internal 64-bit accumulator. |
emh203 | 0:3d9c67d97d6f | 64 | * The input is represented in 1.31 format, which is then downshifted by 8 bits |
emh203 | 0:3d9c67d97d6f | 65 | * which yields 1.23, and intermediate multiplication yields a 2.46 format. |
emh203 | 0:3d9c67d97d6f | 66 | * The accumulator maintains full precision of the intermediate multiplication results, |
emh203 | 0:3d9c67d97d6f | 67 | * but provides only a 16 guard bits. |
emh203 | 0:3d9c67d97d6f | 68 | * There is no saturation on intermediate additions. |
emh203 | 0:3d9c67d97d6f | 69 | * If the accumulator overflows it wraps around and distorts the result. |
emh203 | 0:3d9c67d97d6f | 70 | * In order to avoid overflows completely the input signal must be scaled down by |
emh203 | 0:3d9c67d97d6f | 71 | * log2(blockSize)-8 bits, as a total of blockSize additions are performed internally. |
emh203 | 0:3d9c67d97d6f | 72 | * After division, internal variables should be Q18.46 |
emh203 | 0:3d9c67d97d6f | 73 | * Finally, the 18.46 accumulator is right shifted by 15 bits to yield a 1.31 format value. |
emh203 | 0:3d9c67d97d6f | 74 | * |
emh203 | 0:3d9c67d97d6f | 75 | */ |
emh203 | 0:3d9c67d97d6f | 76 | |
emh203 | 0:3d9c67d97d6f | 77 | |
emh203 | 0:3d9c67d97d6f | 78 | void arm_std_q31( |
emh203 | 0:3d9c67d97d6f | 79 | q31_t * pSrc, |
emh203 | 0:3d9c67d97d6f | 80 | uint32_t blockSize, |
emh203 | 0:3d9c67d97d6f | 81 | q31_t * pResult) |
emh203 | 0:3d9c67d97d6f | 82 | { |
emh203 | 0:3d9c67d97d6f | 83 | q63_t sum = 0; /* Accumulator */ |
emh203 | 0:3d9c67d97d6f | 84 | q63_t meanOfSquares, squareOfMean; /* square of mean and mean of square */ |
emh203 | 0:3d9c67d97d6f | 85 | q31_t in; /* input value */ |
emh203 | 0:3d9c67d97d6f | 86 | uint32_t blkCnt; /* loop counter */ |
emh203 | 0:3d9c67d97d6f | 87 | q63_t sumOfSquares = 0; /* Accumulator */ |
emh203 | 0:3d9c67d97d6f | 88 | |
emh203 | 0:3d9c67d97d6f | 89 | if(blockSize == 1) |
emh203 | 0:3d9c67d97d6f | 90 | { |
emh203 | 0:3d9c67d97d6f | 91 | *pResult = 0; |
emh203 | 0:3d9c67d97d6f | 92 | return; |
emh203 | 0:3d9c67d97d6f | 93 | } |
emh203 | 0:3d9c67d97d6f | 94 | |
emh203 | 0:3d9c67d97d6f | 95 | #ifndef ARM_MATH_CM0_FAMILY |
emh203 | 0:3d9c67d97d6f | 96 | |
emh203 | 0:3d9c67d97d6f | 97 | /* Run the below code for Cortex-M4 and Cortex-M3 */ |
emh203 | 0:3d9c67d97d6f | 98 | |
emh203 | 0:3d9c67d97d6f | 99 | /*loop Unrolling */ |
emh203 | 0:3d9c67d97d6f | 100 | blkCnt = blockSize >> 2u; |
emh203 | 0:3d9c67d97d6f | 101 | |
emh203 | 0:3d9c67d97d6f | 102 | /* First part of the processing with loop unrolling. Compute 4 outputs at a time. |
emh203 | 0:3d9c67d97d6f | 103 | ** a second loop below computes the remaining 1 to 3 samples. */ |
emh203 | 0:3d9c67d97d6f | 104 | while(blkCnt > 0u) |
emh203 | 0:3d9c67d97d6f | 105 | { |
emh203 | 0:3d9c67d97d6f | 106 | /* C = (A[0] * A[0] + A[1] * A[1] + ... + A[blockSize-1] * A[blockSize-1]) */ |
emh203 | 0:3d9c67d97d6f | 107 | /* Compute Sum of squares of the input samples |
emh203 | 0:3d9c67d97d6f | 108 | * and then store the result in a temporary variable, sum. */ |
emh203 | 0:3d9c67d97d6f | 109 | in = *pSrc++ >> 8; |
emh203 | 0:3d9c67d97d6f | 110 | sum += in; |
emh203 | 0:3d9c67d97d6f | 111 | sumOfSquares += ((q63_t) (in) * (in)); |
emh203 | 0:3d9c67d97d6f | 112 | in = *pSrc++ >> 8; |
emh203 | 0:3d9c67d97d6f | 113 | sum += in; |
emh203 | 0:3d9c67d97d6f | 114 | sumOfSquares += ((q63_t) (in) * (in)); |
emh203 | 0:3d9c67d97d6f | 115 | in = *pSrc++ >> 8; |
emh203 | 0:3d9c67d97d6f | 116 | sum += in; |
emh203 | 0:3d9c67d97d6f | 117 | sumOfSquares += ((q63_t) (in) * (in)); |
emh203 | 0:3d9c67d97d6f | 118 | in = *pSrc++ >> 8; |
emh203 | 0:3d9c67d97d6f | 119 | sum += in; |
emh203 | 0:3d9c67d97d6f | 120 | sumOfSquares += ((q63_t) (in) * (in)); |
emh203 | 0:3d9c67d97d6f | 121 | |
emh203 | 0:3d9c67d97d6f | 122 | /* Decrement the loop counter */ |
emh203 | 0:3d9c67d97d6f | 123 | blkCnt--; |
emh203 | 0:3d9c67d97d6f | 124 | } |
emh203 | 0:3d9c67d97d6f | 125 | |
emh203 | 0:3d9c67d97d6f | 126 | /* If the blockSize is not a multiple of 4, compute any remaining output samples here. |
emh203 | 0:3d9c67d97d6f | 127 | ** No loop unrolling is used. */ |
emh203 | 0:3d9c67d97d6f | 128 | blkCnt = blockSize % 0x4u; |
emh203 | 0:3d9c67d97d6f | 129 | |
emh203 | 0:3d9c67d97d6f | 130 | while(blkCnt > 0u) |
emh203 | 0:3d9c67d97d6f | 131 | { |
emh203 | 0:3d9c67d97d6f | 132 | /* C = (A[0] * A[0] + A[1] * A[1] + ... + A[blockSize-1] * A[blockSize-1]) */ |
emh203 | 0:3d9c67d97d6f | 133 | /* Compute Sum of squares of the input samples |
emh203 | 0:3d9c67d97d6f | 134 | * and then store the result in a temporary variable, sum. */ |
emh203 | 0:3d9c67d97d6f | 135 | in = *pSrc++ >> 8; |
emh203 | 0:3d9c67d97d6f | 136 | sum += in; |
emh203 | 0:3d9c67d97d6f | 137 | sumOfSquares += ((q63_t) (in) * (in)); |
emh203 | 0:3d9c67d97d6f | 138 | |
emh203 | 0:3d9c67d97d6f | 139 | /* Decrement the loop counter */ |
emh203 | 0:3d9c67d97d6f | 140 | blkCnt--; |
emh203 | 0:3d9c67d97d6f | 141 | } |
emh203 | 0:3d9c67d97d6f | 142 | |
emh203 | 0:3d9c67d97d6f | 143 | /* Compute Mean of squares of the input samples |
emh203 | 0:3d9c67d97d6f | 144 | * and then store the result in a temporary variable, meanOfSquares. */ |
emh203 | 0:3d9c67d97d6f | 145 | meanOfSquares = sumOfSquares / (q63_t)(blockSize - 1); |
emh203 | 0:3d9c67d97d6f | 146 | |
emh203 | 0:3d9c67d97d6f | 147 | #else |
emh203 | 0:3d9c67d97d6f | 148 | |
emh203 | 0:3d9c67d97d6f | 149 | /* Run the below code for Cortex-M0 */ |
emh203 | 0:3d9c67d97d6f | 150 | |
emh203 | 0:3d9c67d97d6f | 151 | /* Loop over blockSize number of values */ |
emh203 | 0:3d9c67d97d6f | 152 | blkCnt = blockSize; |
emh203 | 0:3d9c67d97d6f | 153 | |
emh203 | 0:3d9c67d97d6f | 154 | while(blkCnt > 0u) |
emh203 | 0:3d9c67d97d6f | 155 | { |
emh203 | 0:3d9c67d97d6f | 156 | /* C = (A[0] * A[0] + A[1] * A[1] + ... + A[blockSize-1] * A[blockSize-1]) */ |
emh203 | 0:3d9c67d97d6f | 157 | /* Compute Sum of squares of the input samples |
emh203 | 0:3d9c67d97d6f | 158 | * and then store the result in a temporary variable, sumOfSquares. */ |
emh203 | 0:3d9c67d97d6f | 159 | in = *pSrc++ >> 8; |
emh203 | 0:3d9c67d97d6f | 160 | sumOfSquares += ((q63_t) (in) * (in)); |
emh203 | 0:3d9c67d97d6f | 161 | |
emh203 | 0:3d9c67d97d6f | 162 | /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) */ |
emh203 | 0:3d9c67d97d6f | 163 | /* Compute sum of all input values and then store the result in a temporary variable, sum. */ |
emh203 | 0:3d9c67d97d6f | 164 | sum += in; |
emh203 | 0:3d9c67d97d6f | 165 | |
emh203 | 0:3d9c67d97d6f | 166 | /* Decrement the loop counter */ |
emh203 | 0:3d9c67d97d6f | 167 | blkCnt--; |
emh203 | 0:3d9c67d97d6f | 168 | } |
emh203 | 0:3d9c67d97d6f | 169 | |
emh203 | 0:3d9c67d97d6f | 170 | /* Compute Mean of squares of the input samples |
emh203 | 0:3d9c67d97d6f | 171 | * and then store the result in a temporary variable, meanOfSquares. */ |
emh203 | 0:3d9c67d97d6f | 172 | meanOfSquares = sumOfSquares / (q63_t)(blockSize - 1); |
emh203 | 0:3d9c67d97d6f | 173 | |
emh203 | 0:3d9c67d97d6f | 174 | #endif /* #ifndef ARM_MATH_CM0_FAMILY */ |
emh203 | 0:3d9c67d97d6f | 175 | |
emh203 | 0:3d9c67d97d6f | 176 | /* Compute square of mean */ |
emh203 | 0:3d9c67d97d6f | 177 | squareOfMean = sum * sum / (q63_t)(blockSize * (blockSize - 1u)); |
emh203 | 0:3d9c67d97d6f | 178 | |
emh203 | 0:3d9c67d97d6f | 179 | /* Compute standard deviation and then store the result to the destination */ |
emh203 | 0:3d9c67d97d6f | 180 | arm_sqrt_q31((meanOfSquares - squareOfMean) >> 15, pResult); |
emh203 | 0:3d9c67d97d6f | 181 | |
emh203 | 0:3d9c67d97d6f | 182 | } |
emh203 | 0:3d9c67d97d6f | 183 | |
emh203 | 0:3d9c67d97d6f | 184 | /** |
emh203 | 0:3d9c67d97d6f | 185 | * @} end of STD group |
emh203 | 0:3d9c67d97d6f | 186 | */ |