Mercurial Hosting > traffic-intelligence
comparison trajectorymanagement/src/DTWMetric.h @ 1159:e1e7acef8eab
moved trajectory management library into Traffic Intelligence
author | Nicolas Saunier <nicolas.saunier@polymtl.ca> |
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date | Mon, 22 Feb 2021 22:09:35 -0500 |
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1158:7eb972942f22 | 1159:e1e7acef8eab |
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1 #ifndef DTWMETRIC_H_ | |
2 #define DTWMETRIC_H_ | |
3 | |
4 #include "Metric.h" | |
5 | |
6 /** | |
7 * DTWMetric class. | |
8 * | |
9 * The Dynamic Time Warping metric measures the similarity between two trajectories. | |
10 */ | |
11 template<typename Tr, typename To> | |
12 class DTWMetric: public Metric<Tr, To> | |
13 { | |
14 public: | |
15 /** | |
16 * Constructor. | |
17 */ | |
18 DTWMetric() | |
19 { | |
20 maxDTWValue = (std::numeric_limits<To>::max()) / To(2); | |
21 } | |
22 | |
23 /** | |
24 * Set maximum value that occurs during the calculation process. | |
25 * | |
26 * @param[in] maxDTWValue maximum value | |
27 */ | |
28 bool setMaxDTWValue(To maxDTWValue) | |
29 { | |
30 if (maxDTWValue >= 0.0) | |
31 { | |
32 this->maxDTWValue = maxDTWValue; | |
33 return true; | |
34 } | |
35 return false; | |
36 } | |
37 | |
38 /** | |
39 * Set maximum value that occurs during the calculation process. | |
40 * | |
41 * @param[in] imgSize image size | |
42 * @param[in] eps machine epsilon | |
43 */ | |
44 bool setMaxDTWValue(CvSize &imgSize, double eps) | |
45 { | |
46 if (imgSize.width > 0 && imgSize.height > 0 && eps > 0) | |
47 { | |
48 cv::Point_<int> p(imgSize.width, imgSize.height); | |
49 maxDTWValue = std::numeric_limits<To>::max() - norm(p) - eps; | |
50 return true; | |
51 } | |
52 return false; | |
53 } | |
54 | |
55 /** | |
56 * Compute similarity between two trajectories. | |
57 * | |
58 * @param[in] a input trajectory | |
59 * @param[in] b input trajectory | |
60 * @param[out] result distance between two trajectories. | |
61 */ | |
62 void distance(const Trajectory<Tr> *a, const Trajectory<Tr> *b, To &result, unsigned int nbOfPoints = std::numeric_limits<unsigned int>::max()) | |
63 { | |
64 To DTW[a->size() + 1][b->size() + 1]; | |
65 | |
66 { //initialization | |
67 for (unsigned int i = 0; i <= a->size(); ++i) | |
68 { | |
69 DTW[i][0] = maxDTWValue; | |
70 } | |
71 | |
72 for (unsigned int j = 0; j <= b->size(); ++j) | |
73 { | |
74 DTW[0][j] = maxDTWValue; | |
75 } | |
76 | |
77 DTW[0][0] = 0.0; | |
78 } | |
79 | |
80 { //algorithm | |
81 for (unsigned int i = 1; i <= a->size(); ++i) | |
82 { | |
83 for (unsigned int j = 1; j <= b->size(); ++j) | |
84 { | |
85 To smallest = min(DTW[i - 1][j], DTW[i][j - 1], DTW[i - 1][j - 1]); | |
86 cv::Point3_<typeof(static_cast<Tr>(a->getPoint(i-1)).x)> p(a->getPoint(i - 1) - b->getPoint(j - 1)); | |
87 To distance = std::sqrt(std::pow(p.x, 2) + std::pow(p.y, 2) + std::pow(p.z, 2)); | |
88 DTW[i][j] = std::min(smallest + distance, maxDTWValue); | |
89 } | |
90 } | |
91 } | |
92 | |
93 result = DTW[a->size()][b->size()]; | |
94 } | |
95 | |
96 private: | |
97 /** | |
98 * Maximum value that occurs during the calculation process. | |
99 */ | |
100 To maxDTWValue; | |
101 | |
102 /** | |
103 * Compute the minimum of \a a, \a b and \c c. | |
104 * | |
105 * @param[in] a input parameter | |
106 * @param[in] b input parameter | |
107 * @param[in] c input parameter | |
108 */ | |
109 To min(To a, To b, To c) | |
110 { | |
111 return std::min(std::min(a, b), c); | |
112 } | |
113 }; | |
114 | |
115 #endif /* DTWMETRIC_H_ */ |