Developer Documentation

DBSCANT.hh
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40 \*===========================================================================*/
41
42 #ifndef DBSCAN_HH_
43 #define DBSCAN_HH_
44
45 #include <vector>
46 #include <iterator>
47 #include <algorithm>
48
49 /*
50 * Private functions.
51 */
52 #include "DBSCANT.cc"
53
54 namespace ACG {
55 namespace Algorithm {
56
88 template<typename INPUT_ITERATOR, typename DISTANCE_FUNC, typename OUTPUT_ITERATOR, typename WEIGHT_FUNC>
89 int DBSCAN(const INPUT_ITERATOR first, const INPUT_ITERATOR last, DISTANCE_FUNC distance_func,
90 OUTPUT_ITERATOR result, const double epsilon, const double n_min, WEIGHT_FUNC weight_func) {
91
92 const size_t input_size = std::distance(first, last);
93
94 std::vector<int> id_cache(input_size, -1);
95
96 int idx = 0;
97 int current_cluster_id = 0;
98
99 for (INPUT_ITERATOR it = first; it != last; ++it, ++idx) {
100
101 // Visit every element only once.
102 if (id_cache[idx] >= 0) continue;
103
104 // Gather neighborhood.
105 std::vector<INPUT_ITERATOR> neighborhood; neighborhood.reserve(input_size);
106 _DBSCAN_PRIVATE::region_query(first, last, it, distance_func, std::back_inserter(neighborhood), epsilon);
107
108 if (_DBSCAN_PRIVATE::neighborhoodWeight(neighborhood.begin(), neighborhood.end(), weight_func) < n_min) {
109 // It's noise.
110 id_cache[idx] = 0;
111 } else {
112 // It's the seed of a cluster.
113 _DBSCAN_PRIVATE::expand_cluster(first, last, it, distance_func, epsilon, n_min, id_cache, ++current_cluster_id, weight_func);
114 }
115 }
116
117 std::copy(id_cache.begin(), id_cache.end(), result);
118
119 return current_cluster_id;
120 }
121
125 template<typename INPUT_ITERATOR, typename DISTANCE_FUNC, typename OUTPUT_ITERATOR>
126 int DBSCAN(const INPUT_ITERATOR first, const INPUT_ITERATOR last, DISTANCE_FUNC distance_func,
127 OUTPUT_ITERATOR result, const double epsilon, const double n_min) {
128 return DBSCAN(first, last, distance_func, result, epsilon, n_min, typename _DBSCAN_PRIVATE::constant_1<typename INPUT_ITERATOR::value_type>());
129 }
130
131 } /* namespace Algorithm */
132 } /* namespace ACG */
133 #endif /* DBSCAN_HH_ */
ACG
Namespace providing different geometric functions concerning angles.
Definition: BaseObjectData.hh:68