1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_absmax_f64.c
4 * Description: Maximum value of absolute values of a floating-point vector
5 *
6 * $Date: 13 September 2021
7 * $Revision: V1.10.0
8 *
9 * Target Processor: Cortex-M and Cortex-A cores
10 * -------------------------------------------------------------------- */
11 /*
12 * Copyright (C) 2010-2021 ARM Limited or its affiliates. All rights reserved.
13 *
14 * SPDX-License-Identifier: Apache-2.0
15 *
16 * Licensed under the Apache License, Version 2.0 (the License); you may
17 * not use this file except in compliance with the License.
18 * You may obtain a copy of the License at
19 *
20 * www.apache.org/licenses/LICENSE-2.0
21 *
22 * Unless required by applicable law or agreed to in writing, software
23 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
24 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
25 * See the License for the specific language governing permissions and
26 * limitations under the License.
27 */
28
29 #include "dsp/statistics_functions.h"
30
31 /**
32 @ingroup groupStats
33 */
34
35 /**
36 @addtogroup AbsMax
37 @{
38 */
39
40 /**
41 @brief Maximum value of absolute values of a floating-point vector.
42 @param[in] pSrc points to the input vector
43 @param[in] blockSize number of samples in input vector
44 @param[out] pResult maximum value returned here
45 @param[out] pIndex index of maximum value returned here
46 */
arm_absmax_f64(const float64_t * pSrc,uint32_t blockSize,float64_t * pResult,uint32_t * pIndex)47 ARM_DSP_ATTRIBUTE void arm_absmax_f64(
48 const float64_t * pSrc,
49 uint32_t blockSize,
50 float64_t * pResult,
51 uint32_t * pIndex)
52 {
53 float64_t maxVal, out; /* Temporary variables to store the output value. */
54 uint32_t blkCnt, outIndex; /* Loop counter */
55
56
57
58 /* Initialise index value to zero. */
59 outIndex = 0U;
60
61 /* Load first input value that act as reference value for comparision */
62 out = fabs(*pSrc++);
63
64 /* Initialize blkCnt with number of samples */
65 blkCnt = (blockSize - 1U);
66
67 while (blkCnt > 0U)
68 {
69 /* Initialize maxVal to the next consecutive values one by one */
70 maxVal = fabs(*pSrc++);
71
72 /* compare for the maximum value */
73 if (out < maxVal)
74 {
75 /* Update the maximum value and it's index */
76 out = maxVal;
77 outIndex = blockSize - blkCnt;
78 }
79
80 /* Decrement loop counter */
81 blkCnt--;
82 }
83
84 /* Store the maximum value and it's index into destination pointers */
85 *pResult = out;
86 *pIndex = outIndex;
87 }
88
89 /**
90 @} end of AbsMax group
91 */
92
