1 // Ceres Solver - A fast non-linear least squares minimizer
2 // Copyright 2013 Google Inc. All rights reserved.
3 // http://code.google.com/p/ceres-solver/
4 //
5 // Redistribution and use in source and binary forms, with or without
6 // modification, are permitted provided that the following conditions are met:
7 //
8 // * Redistributions of source code must retain the above copyright notice,
9 // this list of conditions and the following disclaimer.
10 // * Redistributions in binary form must reproduce the above copyright notice,
11 // this list of conditions and the following disclaimer in the documentation
12 // and/or other materials provided with the distribution.
13 // * Neither the name of Google Inc. nor the names of its contributors may be
14 // used to endorse or promote products derived from this software without
15 // specific prior written permission.
16 //
17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18 // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
21 // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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26 // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 // POSSIBILITY OF SUCH DAMAGE.
28 //
29 // Author: Sameer Agarwal (sameeragarwal@google.com)
30
31 // This include must come before any #ifndef check on Ceres compile options.
32 #include "ceres/internal/port.h"
33
34 #ifndef CERES_NO_SUITESPARSE
35
36 #include "ceres/single_linkage_clustering.h"
37
38 #include "ceres/collections_port.h"
39 #include "ceres/graph.h"
40 #include "gtest/gtest.h"
41
42 namespace ceres {
43 namespace internal {
44
TEST(SingleLinkageClustering,GraphHasTwoComponents)45 TEST(SingleLinkageClustering, GraphHasTwoComponents) {
46 Graph<int> graph;
47 const int kNumVertices = 6;
48 for (int i = 0; i < kNumVertices; ++i) {
49 graph.AddVertex(i);
50 }
51 // Graph structure:
52 //
53 // 0-1-2-3 4-5
54 graph.AddEdge(0, 1, 1.0);
55 graph.AddEdge(1, 2, 1.0);
56 graph.AddEdge(2, 3, 1.0);
57 graph.AddEdge(4, 5, 1.0);
58
59 SingleLinkageClusteringOptions options;
60 HashMap<int, int> membership;
61 ComputeSingleLinkageClustering(options, graph, &membership);
62 EXPECT_EQ(membership.size(), kNumVertices);
63
64 EXPECT_EQ(membership[1], membership[0]);
65 EXPECT_EQ(membership[2], membership[0]);
66 EXPECT_EQ(membership[3], membership[0]);
67 EXPECT_NE(membership[4], membership[0]);
68 EXPECT_NE(membership[5], membership[0]);
69 EXPECT_EQ(membership[4], membership[5]);
70 }
71
TEST(SingleLinkageClustering,ComponentWithWeakLink)72 TEST(SingleLinkageClustering, ComponentWithWeakLink) {
73 Graph<int> graph;
74 const int kNumVertices = 6;
75 for (int i = 0; i < kNumVertices; ++i) {
76 graph.AddVertex(i);
77 }
78 // Graph structure:
79 //
80 // 0-1-2-3 4-5
81 graph.AddEdge(0, 1, 1.0);
82 graph.AddEdge(1, 2, 1.0);
83 graph.AddEdge(2, 3, 1.0);
84
85 // This component should break up into two.
86 graph.AddEdge(4, 5, 0.5);
87
88 SingleLinkageClusteringOptions options;
89 HashMap<int, int> membership;
90 ComputeSingleLinkageClustering(options, graph, &membership);
91 EXPECT_EQ(membership.size(), kNumVertices);
92
93 EXPECT_EQ(membership[1], membership[0]);
94 EXPECT_EQ(membership[2], membership[0]);
95 EXPECT_EQ(membership[3], membership[0]);
96 EXPECT_NE(membership[4], membership[0]);
97 EXPECT_NE(membership[5], membership[0]);
98 EXPECT_NE(membership[4], membership[5]);
99 }
100
TEST(SingleLinkageClustering,ComponentWithWeakLinkAndStrongLink)101 TEST(SingleLinkageClustering, ComponentWithWeakLinkAndStrongLink) {
102 Graph<int> graph;
103 const int kNumVertices = 6;
104 for (int i = 0; i < kNumVertices; ++i) {
105 graph.AddVertex(i);
106 }
107 // Graph structure:
108 //
109 // 0-1-2-3 4-5
110 graph.AddEdge(0, 1, 1.0);
111 graph.AddEdge(1, 2, 1.0);
112 graph.AddEdge(2, 3, 0.5); // Weak link
113 graph.AddEdge(0, 3, 1.0);
114
115 // This component should break up into two.
116 graph.AddEdge(4, 5, 1.0);
117
118 SingleLinkageClusteringOptions options;
119 HashMap<int, int> membership;
120 ComputeSingleLinkageClustering(options, graph, &membership);
121 EXPECT_EQ(membership.size(), kNumVertices);
122
123 EXPECT_EQ(membership[1], membership[0]);
124 EXPECT_EQ(membership[2], membership[0]);
125 EXPECT_EQ(membership[3], membership[0]);
126 EXPECT_EQ(membership[4], membership[5]);
127 }
128
129 } // namespace internal
130 } // namespace ceres
131
132 #endif // CERES_NO_SUITESPARSE
133