1 /* ----------------------------------------------------------------------
2 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
4 * $Date: 17. January 2013
7 * Project: CMSIS DSP Library
8 * Title: arm_mean_f32.c
10 * Description: Mean value of a floating-point vector.
12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
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15 * modification, are permitted provided that the following conditions
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18 * notice, this list of conditions and the following disclaimer.
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20 * notice, this list of conditions and the following disclaimer in
21 * the documentation and/or other materials provided with the
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25 * software without specific prior written permission.
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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30 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
31 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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39 * ---------------------------------------------------------------------------- */
50 * Calculates the mean of the input vector. Mean is defined as the average of the elements in the vector.
51 * The underlying algorithm is used:
54 * Result = (pSrc[0] + pSrc[1] + pSrc[2] + ... + pSrc[blockSize-1]) / blockSize;
57 * There are separate functions for floating-point, Q31, Q15, and Q7 data types.
67 * @brief Mean value of a floating-point vector.
68 * @param[in] *pSrc points to the input vector
69 * @param[in] blockSize length of the input vector
70 * @param[out] *pResult mean value returned here
80 float32_t sum = 0.0f; /* Temporary result storage */
81 uint32_t blkCnt; /* loop counter */
83 #ifndef ARM_MATH_CM0_FAMILY
85 /* Run the below code for Cortex-M4 and Cortex-M3 */
86 float32_t in1, in2, in3, in4;
89 blkCnt = blockSize >> 2u;
91 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
92 ** a second loop below computes the remaining 1 to 3 samples. */
95 /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) */
106 /* Decrement the loop counter */
110 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
111 ** No loop unrolling is used. */
112 blkCnt = blockSize % 0x4u;
116 /* Run the below code for Cortex-M0 */
118 /* Loop over blockSize number of values */
121 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
125 /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) */
128 /* Decrement the loop counter */
132 /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) / blockSize */
133 /* Store the result to the destination */
134 *pResult = sum / (float32_t) blockSize;
138 * @} end of mean group