1  /* ----------------------------------------------------------------------
 2   * Project:      CMSIS DSP Library
 3   * Title:        arm_absmax_no_idx_f64.c
 4   * Description:  Maximum value of absolute values of a floating-point vector
 5   *
 6   * $Date:        16 November 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    @return        none
46   */
47  void arm_absmax_no_idx_f64(
48    const float64_t * pSrc,
49          uint32_t blockSize,
50          float64_t * pResult)
51  {
52          float64_t maxVal, out;                         /* Temporary variables to store the output value. */
53          uint32_t blkCnt;                     /* Loop counter */
54  
55  
56  
57  
58  
59    /* Load first input value that act as reference value for comparision */
60    out = fabs(*pSrc++);
61  
62    /* Initialize blkCnt with number of samples */
63    blkCnt = (blockSize - 1U);
64  
65    while (blkCnt > 0U)
66    {
67      /* Initialize maxVal to the next consecutive values one by one */
68      maxVal = fabs(*pSrc++);
69  
70      /* compare for the maximum value */
71      if (out < maxVal)
72      {
73        /* Update the maximum value and it's index */
74        out = maxVal;
75      }
76  
77      /* Decrement loop counter */
78      blkCnt--;
79    }
80  
81    /* Store the maximum value and it's index into destination pointers */
82    *pResult = out;
83  }
84  
85  /**
86    @} end of AbsMax group
87   */