1
2 /* ----------------------------------------------------------------------
3 * Project: CMSIS DSP Library
4 * Title: arm_correlation_distance_f16.c
5 * Description: Correlation distance between two vectors
6 *
7 * $Date: 23 April 2021
8 * $Revision: V1.9.0
9 *
10 * Target Processor: Cortex-M and Cortex-A cores
11 * -------------------------------------------------------------------- */
12 /*
13 * Copyright (C) 2010-2021 ARM Limited or its affiliates. All rights reserved.
14 *
15 * SPDX-License-Identifier: Apache-2.0
16 *
17 * Licensed under the Apache License, Version 2.0 (the License); you may
18 * not use this file except in compliance with the License.
19 * You may obtain a copy of the License at
20 *
21 * www.apache.org/licenses/LICENSE-2.0
22 *
23 * Unless required by applicable law or agreed to in writing, software
24 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
25 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
26 * See the License for the specific language governing permissions and
27 * limitations under the License.
28 */
29
30 #include "dsp/distance_functions_f16.h"
31
32 #if defined(ARM_FLOAT16_SUPPORTED)
33
34 #include <limits.h>
35 #include <math.h>
36
37
38 /**
39 @ingroup FloatDist
40 */
41
42 /**
43 @defgroup Correlation Correlation distance
44
45 Correlation distance
46 */
47
48 /**
49 @addtogroup Correlation
50 @{
51 */
52
53
54 /**
55 * @brief Correlation distance between two vectors
56 *
57 * The input vectors are modified in place !
58 *
59 * @param[in] pA First vector
60 * @param[in] pB Second vector
61 * @param[in] blockSize vector length
62 * @return distance
63 *
64 */
65
arm_correlation_distance_f16(float16_t * pA,float16_t * pB,uint32_t blockSize)66 float16_t arm_correlation_distance_f16(float16_t *pA,float16_t *pB, uint32_t blockSize)
67 {
68 float16_t ma,mb,pwra,pwrb,dot,tmp;
69
70 arm_mean_f16(pA, blockSize, &ma);
71 arm_mean_f16(pB, blockSize, &mb);
72
73 arm_offset_f16(pA, -ma, pA, blockSize);
74 arm_offset_f16(pB, -mb, pB, blockSize);
75
76 arm_power_f16(pA, blockSize, &pwra);
77 arm_power_f16(pB, blockSize, &pwrb);
78
79 arm_dot_prod_f16(pA,pB,blockSize,&dot);
80
81 dot = dot / blockSize;
82 pwra = pwra / blockSize;
83 pwrb = pwrb / blockSize;
84
85 arm_sqrt_f16(pwra * pwrb,&tmp);
86
87 return(1.0f - dot / tmp);
88
89
90 }
91
92
93
94 /**
95 * @} end of Correlation group
96 */
97
98 #endif /* #if defined(ARM_FLOAT16_SUPPORTED) */
99
100