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Diffstat (limited to 'internal/ceres/graph_algorithms_test.cc')
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1 files changed, 200 insertions, 0 deletions
diff --git a/internal/ceres/graph_algorithms_test.cc b/internal/ceres/graph_algorithms_test.cc new file mode 100644 index 0000000..d5d4843 --- /dev/null +++ b/internal/ceres/graph_algorithms_test.cc @@ -0,0 +1,200 @@ +// Ceres Solver - A fast non-linear least squares minimizer +// Copyright 2010, 2011, 2012 Google Inc. All rights reserved. +// http://code.google.com/p/ceres-solver/ +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are met: +// +// * Redistributions of source code must retain the above copyright notice, +// this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above copyright notice, +// this list of conditions and the following disclaimer in the documentation +// and/or other materials provided with the distribution. +// * Neither the name of Google Inc. nor the names of its contributors may be +// used to endorse or promote products derived from this software without +// specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE +// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +// POSSIBILITY OF SUCH DAMAGE. +// +// Author: sameeragarwal@google.com (Sameer Agarwal) + +#include "ceres/graph_algorithms.h" + +#include <algorithm> +#include "gtest/gtest.h" +#include "ceres/collections_port.h" +#include "ceres/graph.h" +#include "ceres/internal/port.h" +#include "ceres/internal/scoped_ptr.h" + +namespace ceres { +namespace internal { + +TEST(IndependentSetOrdering, Chain) { + Graph<int> graph; + graph.AddVertex(0); + graph.AddVertex(1); + graph.AddVertex(2); + graph.AddVertex(3); + graph.AddVertex(4); + + graph.AddEdge(0, 1); + graph.AddEdge(1, 2); + graph.AddEdge(2, 3); + graph.AddEdge(3, 4); + + // 0-1-2-3-4 + // 0, 2, 4 should be in the independent set. + vector<int> ordering; + int independent_set_size = IndependentSetOrdering(graph, &ordering); + + sort(ordering.begin(), ordering.begin() + 3); + sort(ordering.begin() + 3, ordering.end()); + + EXPECT_EQ(independent_set_size, 3); + EXPECT_EQ(ordering.size(), 5); + EXPECT_EQ(ordering[0], 0); + EXPECT_EQ(ordering[1], 2); + EXPECT_EQ(ordering[2], 4); + EXPECT_EQ(ordering[3], 1); + EXPECT_EQ(ordering[4], 3); +} + +TEST(IndependentSetOrdering, Star) { + Graph<int> graph; + graph.AddVertex(0); + graph.AddVertex(1); + graph.AddVertex(2); + graph.AddVertex(3); + graph.AddVertex(4); + + graph.AddEdge(0, 1); + graph.AddEdge(0, 2); + graph.AddEdge(0, 3); + graph.AddEdge(0, 4); + + // 1 + // | + // 4-0-2 + // | + // 3 + // 1, 2, 3, 4 should be in the indepdendent set. + vector<int> ordering; + int independent_set_size = IndependentSetOrdering(graph, &ordering); + EXPECT_EQ(independent_set_size, 4); + EXPECT_EQ(ordering.size(), 5); + EXPECT_EQ(ordering[4], 0); + sort(ordering.begin(), ordering.begin() + 4); + EXPECT_EQ(ordering[0], 1); + EXPECT_EQ(ordering[1], 2); + EXPECT_EQ(ordering[2], 3); + EXPECT_EQ(ordering[3], 4); +} + +TEST(Degree2MaximumSpanningForest, PreserveWeights) { + Graph<int> graph; + graph.AddVertex(0, 1.0); + graph.AddVertex(1, 2.0); + graph.AddEdge(0, 1, 0.5); + graph.AddEdge(1, 0, 0.5); + + scoped_ptr<Graph<int> > forest(Degree2MaximumSpanningForest(graph)); + + const HashSet<int>& vertices = forest->vertices(); + EXPECT_EQ(vertices.size(), 2); + EXPECT_EQ(forest->VertexWeight(0), 1.0); + EXPECT_EQ(forest->VertexWeight(1), 2.0); + EXPECT_EQ(forest->Neighbors(0).size(), 1.0); + EXPECT_EQ(forest->EdgeWeight(0, 1), 0.5); +} + +TEST(Degree2MaximumSpanningForest, StarGraph) { + Graph<int> graph; + graph.AddVertex(0); + graph.AddVertex(1); + graph.AddVertex(2); + graph.AddVertex(3); + graph.AddVertex(4); + + graph.AddEdge(0, 1, 1.0); + graph.AddEdge(0, 2, 2.0); + graph.AddEdge(0, 3, 3.0); + graph.AddEdge(0, 4, 4.0); + + scoped_ptr<Graph<int> > forest(Degree2MaximumSpanningForest(graph)); + const HashSet<int>& vertices = forest->vertices(); + EXPECT_EQ(vertices.size(), 5); + + { + const HashSet<int>& neighbors = forest->Neighbors(0); + EXPECT_EQ(neighbors.size(), 2); + EXPECT_TRUE(neighbors.find(4) != neighbors.end()); + EXPECT_TRUE(neighbors.find(3) != neighbors.end()); + } + + { + const HashSet<int>& neighbors = forest->Neighbors(3); + EXPECT_EQ(neighbors.size(), 1); + EXPECT_TRUE(neighbors.find(0) != neighbors.end()); + } + + { + const HashSet<int>& neighbors = forest->Neighbors(4); + EXPECT_EQ(neighbors.size(), 1); + EXPECT_TRUE(neighbors.find(0) != neighbors.end()); + } + + { + const HashSet<int>& neighbors = forest->Neighbors(1); + EXPECT_EQ(neighbors.size(), 0); + } + + { + const HashSet<int>& neighbors = forest->Neighbors(2); + EXPECT_EQ(neighbors.size(), 0); + } +} + +TEST(VertexDegreeLessThan, TotalOrdering) { + Graph<int> graph; + graph.AddVertex(0); + graph.AddVertex(1); + graph.AddVertex(2); + graph.AddVertex(3); + + // 0-1 + // | + // 2-3 + // 0,1 and 2 have degree 1 and 3 has degree 2. + graph.AddEdge(0, 1, 1.0); + graph.AddEdge(2, 3, 1.0); + VertexDegreeLessThan<int> less_than(graph); + + for (int i = 0; i < 4; ++i) { + EXPECT_FALSE(less_than(i,i)) << "Failing vertex: " << i; + for (int j = 0; j < 4; ++j) { + if (i != j) { + EXPECT_TRUE(less_than(i, j) ^ less_than(j, i)) + << "Failing vertex pair: " << i << " " << j; + } + } + } + + for (int i = 0; i < 3; ++i) { + EXPECT_TRUE(less_than(i, 3)); + EXPECT_FALSE(less_than(3, i)); + } +} + +} // namespace internal +} // namespace ceres |