1 // Ceres Solver - A fast non-linear least squares minimizer
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3 // http://code.google.com/p/ceres-solver/
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29 // Author: sameeragarwal@google.com (Sameer Agarwal)
30 
31 #include "ceres/graph.h"
32 
33 #include "gtest/gtest.h"
34 #include "ceres/collections_port.h"
35 #include "ceres/internal/scoped_ptr.h"
36 
37 namespace ceres {
38 namespace internal {
39 
TEST(Graph,EmptyGraph)40 TEST(Graph, EmptyGraph) {
41   Graph<int> graph;
42   EXPECT_EQ(graph.vertices().size(), 0);
43 }
44 
TEST(Graph,AddVertexAndEdge)45 TEST(Graph, AddVertexAndEdge) {
46   Graph<int> graph;
47   graph.AddVertex(0, 1.0);
48   graph.AddVertex(1, 2.0);
49   graph.AddEdge(0, 1, 0.5);
50 
51   const HashSet<int>& vertices = graph.vertices();
52   EXPECT_EQ(vertices.size(), 2);
53   EXPECT_EQ(graph.VertexWeight(0), 1.0);
54   EXPECT_EQ(graph.VertexWeight(1), 2.0);
55   EXPECT_EQ(graph.Neighbors(0).size(), 1);
56   EXPECT_EQ(graph.Neighbors(1).size(), 1);
57   EXPECT_EQ(graph.EdgeWeight(0, 1), 0.5);
58   EXPECT_EQ(graph.EdgeWeight(1, 0), 0.5);
59 }
60 
TEST(Graph,AddVertexIdempotence)61 TEST(Graph, AddVertexIdempotence) {
62   Graph<int> graph;
63   graph.AddVertex(0, 1.0);
64   graph.AddVertex(1, 2.0);
65   graph.AddEdge(0, 1, 0.5);
66 
67   const HashSet<int>& vertices = graph.vertices();
68 
69   EXPECT_EQ(vertices.size(), 2);
70 
71   // Try adding the vertex again with a new weight.
72   graph.AddVertex(0, 3.0);
73   EXPECT_EQ(vertices.size(), 2);
74 
75   // The vertex weight is reset.
76   EXPECT_EQ(graph.VertexWeight(0), 3.0);
77 
78   // Rest of the graph remains the same.
79   EXPECT_EQ(graph.VertexWeight(1), 2.0);
80   EXPECT_EQ(graph.Neighbors(0).size(), 1);
81   EXPECT_EQ(graph.Neighbors(1).size(), 1);
82   EXPECT_EQ(graph.EdgeWeight(0, 1), 0.5);
83   EXPECT_EQ(graph.EdgeWeight(1, 0), 0.5);
84 }
85 
TEST(Graph,DieOnNonExistentVertex)86 TEST(Graph, DieOnNonExistentVertex) {
87   Graph<int> graph;
88   graph.AddVertex(0, 1.0);
89   graph.AddVertex(1, 2.0);
90   graph.AddEdge(0, 1, 0.5);
91 
92   EXPECT_DEATH_IF_SUPPORTED(graph.VertexWeight(2), "key not found");
93   EXPECT_DEATH_IF_SUPPORTED(graph.Neighbors(2), "key not found");
94 }
95 
TEST(Graph,NonExistentEdge)96 TEST(Graph, NonExistentEdge) {
97   Graph<int> graph;
98   graph.AddVertex(0, 1.0);
99   graph.AddVertex(1, 2.0);
100   graph.AddEdge(0, 1, 0.5);
101 
102   // Default value for non-existent edges is 0.
103   EXPECT_EQ(graph.EdgeWeight(2, 3), 0);
104 }
105 
106 }  // namespace internal
107 }  // namespace ceres
108