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comparison f103c8/Drivers/CMSIS/DSP_Lib/Source/StatisticsFunctions/arm_rms_f32.c @ 2:0c59e7a7782a

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Working on GPIO and RCC
author cin
date Mon, 16 Jan 2017 11:04:47 +0300
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1:a0b14b11ad9f 2:0c59e7a7782a
1 /* ----------------------------------------------------------------------
2 * Copyright (C) 2010-2014 ARM Limited. All rights reserved.
3 *
4 * $Date: 19. March 2015
5 * $Revision: V.1.4.5
6 *
7 * Project: CMSIS DSP Library
8 * Title: arm_rms_f32.c
9 *
10 * Description: Root mean square value of an array of F32 type
11 *
12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * - Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * - Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in
21 * the documentation and/or other materials provided with the
22 * distribution.
23 * - Neither the name of ARM LIMITED nor the names of its contributors
24 * may be used to endorse or promote products derived from this
25 * software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
30 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
31 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
33 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
34 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
35 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
37 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38 * POSSIBILITY OF SUCH DAMAGE.
39 * ---------------------------------------------------------------------------- */
40
41 #include "arm_math.h"
42
43 /**
44 * @ingroup groupStats
45 */
46
47 /**
48 * @defgroup RMS Root mean square (RMS)
49 *
50 *
51 * Calculates the Root Mean Sqaure of the elements in the input vector.
52 * The underlying algorithm is used:
53 *
54 * <pre>
55 * Result = sqrt(((pSrc[0] * pSrc[0] + pSrc[1] * pSrc[1] + ... + pSrc[blockSize-1] * pSrc[blockSize-1]) / blockSize));
56 * </pre>
57 *
58 * There are separate functions for floating point, Q31, and Q15 data types.
59 */
60
61 /**
62 * @addtogroup RMS
63 * @{
64 */
65
66
67 /**
68 * @brief Root Mean Square of the elements of a floating-point vector.
69 * @param[in] *pSrc points to the input vector
70 * @param[in] blockSize length of the input vector
71 * @param[out] *pResult rms value returned here
72 * @return none.
73 *
74 */
75
76 void arm_rms_f32(
77 float32_t * pSrc,
78 uint32_t blockSize,
79 float32_t * pResult)
80 {
81 float32_t sum = 0.0f; /* Accumulator */
82 float32_t in; /* Tempoprary variable to store input value */
83 uint32_t blkCnt; /* loop counter */
84
85 #ifndef ARM_MATH_CM0_FAMILY
86
87 /* Run the below code for Cortex-M4 and Cortex-M3 */
88
89 /* loop Unrolling */
90 blkCnt = blockSize >> 2u;
91
92 /* First part of the processing with loop unrolling. Compute 4 outputs at a time.
93 ** a second loop below computes the remaining 1 to 3 samples. */
94 while(blkCnt > 0u)
95 {
96 /* C = A[0] * A[0] + A[1] * A[1] + A[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */
97 /* Compute sum of the squares and then store the result in a temporary variable, sum */
98 in = *pSrc++;
99 sum += in * in;
100 in = *pSrc++;
101 sum += in * in;
102 in = *pSrc++;
103 sum += in * in;
104 in = *pSrc++;
105 sum += in * in;
106
107 /* Decrement the loop counter */
108 blkCnt--;
109 }
110
111 /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
112 ** No loop unrolling is used. */
113 blkCnt = blockSize % 0x4u;
114
115 #else
116
117 /* Run the below code for Cortex-M0 */
118
119 /* Loop over blockSize number of values */
120 blkCnt = blockSize;
121
122 #endif /* #ifndef ARM_MATH_CM0_FAMILY */
123
124 while(blkCnt > 0u)
125 {
126 /* C = A[0] * A[0] + A[1] * A[1] + A[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */
127 /* Compute sum of the squares and then store the results in a temporary variable, sum */
128 in = *pSrc++;
129 sum += in * in;
130
131 /* Decrement the loop counter */
132 blkCnt--;
133 }
134
135 /* Compute Rms and store the result in the destination */
136 arm_sqrt_f32(sum / (float32_t) blockSize, pResult);
137 }
138
139 /**
140 * @} end of RMS group
141 */