| /* ---------------------------------------------------------------------- |
| * Copyright (C) 2010-2014 ARM Limited. All rights reserved. |
| * |
| * $Date: 19. March 2015 |
| * $Revision: V.1.4.5 |
| * |
| * Project: CMSIS DSP Library |
| * Title: arm_mean_f32.c |
| * |
| * Description: Mean value of a floating-point vector. |
| * |
| * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * - Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * - Neither the name of ARM LIMITED nor the names of its contributors |
| * may be used to endorse or promote products derived from this |
| * software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
| * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| * POSSIBILITY OF SUCH DAMAGE. |
| * ---------------------------------------------------------------------------- */ |
| |
| #include "arm_math.h" |
| |
| /** |
| * @ingroup groupStats |
| */ |
| |
| /** |
| * @defgroup mean Mean |
| * |
| * Calculates the mean of the input vector. Mean is defined as the average of the elements in the vector. |
| * The underlying algorithm is used: |
| * |
| * <pre> |
| * Result = (pSrc[0] + pSrc[1] + pSrc[2] + ... + pSrc[blockSize-1]) / blockSize; |
| * </pre> |
| * |
| * There are separate functions for floating-point, Q31, Q15, and Q7 data types. |
| */ |
| |
| /** |
| * @addtogroup mean |
| * @{ |
| */ |
| |
| |
| /** |
| * @brief Mean value of a floating-point vector. |
| * @param[in] *pSrc points to the input vector |
| * @param[in] blockSize length of the input vector |
| * @param[out] *pResult mean value returned here |
| * @return none. |
| */ |
| |
| |
| void arm_mean_f32( |
| float32_t * pSrc, |
| uint32_t blockSize, |
| float32_t * pResult) |
| { |
| float32_t sum = 0.0f; /* Temporary result storage */ |
| uint32_t blkCnt; /* loop counter */ |
| |
| #ifndef ARM_MATH_CM0_FAMILY |
| |
| /* Run the below code for Cortex-M4 and Cortex-M3 */ |
| float32_t in1, in2, in3, in4; |
| |
| /*loop Unrolling */ |
| blkCnt = blockSize >> 2u; |
| |
| /* First part of the processing with loop unrolling. Compute 4 outputs at a time. |
| ** a second loop below computes the remaining 1 to 3 samples. */ |
| while(blkCnt > 0u) |
| { |
| /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) */ |
| in1 = *pSrc++; |
| in2 = *pSrc++; |
| in3 = *pSrc++; |
| in4 = *pSrc++; |
| |
| sum += in1; |
| sum += in2; |
| sum += in3; |
| sum += in4; |
| |
| /* Decrement the loop counter */ |
| blkCnt--; |
| } |
| |
| /* If the blockSize is not a multiple of 4, compute any remaining output samples here. |
| ** No loop unrolling is used. */ |
| blkCnt = blockSize % 0x4u; |
| |
| #else |
| |
| /* Run the below code for Cortex-M0 */ |
| |
| /* Loop over blockSize number of values */ |
| blkCnt = blockSize; |
| |
| #endif /* #ifndef ARM_MATH_CM0_FAMILY */ |
| |
| while(blkCnt > 0u) |
| { |
| /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) */ |
| sum += *pSrc++; |
| |
| /* Decrement the loop counter */ |
| blkCnt--; |
| } |
| |
| /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) / blockSize */ |
| /* Store the result to the destination */ |
| *pResult = sum / (float32_t) blockSize; |
| } |
| |
| /** |
| * @} end of mean group |
| */ |