1 
2 /* ----------------------------------------------------------------------
3  * Project:      CMSIS DSP Library
4  * Title:        arm_yule_distance.c
5  * Description:  Yule 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.h"
31 #include <limits.h>
32 #include <math.h>
33 
34 
35 extern void arm_boolean_distance_TT_FF_TF_FT(const uint32_t *pA
36        , const uint32_t *pB
37        , uint32_t numberOfBools
38        , uint32_t *cTT
39        , uint32_t *cFF
40        , uint32_t *cTF
41        , uint32_t *cFT
42        );
43 
44 /**
45   @addtogroup BoolDist
46   @{
47  */
48 
49 
50 /**
51  * @brief        Yule distance between two vectors
52  *
53  * @param[in]    pA              First vector of packed booleans
54  * @param[in]    pB              Second vector of packed booleans
55  * @param[in]    numberOfBools   Number of booleans
56  * @return distance
57  *
58  */
59 
arm_yule_distance(const uint32_t * pA,const uint32_t * pB,uint32_t numberOfBools)60 float32_t arm_yule_distance(const uint32_t *pA, const uint32_t *pB, uint32_t numberOfBools)
61 {
62     uint32_t ctt=0,cff=0,ctf=0,cft=0,r;
63 
64     arm_boolean_distance_TT_FF_TF_FT(pA, pB, numberOfBools, &ctt,&cff, &ctf, &cft);
65 
66     r = 2*(ctf * cft);
67 
68     return(1.0*r / (r/2.0 + ctt * cff));
69 }
70 
71 
72 /**
73  * @} end of BoolDist group
74  */
75