001/**
002 * Copyright (c) 2011, The University of Southampton and the individual contributors.
003 * All rights reserved.
004 *
005 * Redistribution and use in source and binary forms, with or without modification,
006 * are permitted provided that the following conditions are met:
007 *
008 *   *  Redistributions of source code must retain the above copyright notice,
009 *      this list of conditions and the following disclaimer.
010 *
011 *   *  Redistributions in binary form must reproduce the above copyright notice,
012 *      this list of conditions and the following disclaimer in the documentation
013 *      and/or other materials provided with the distribution.
014 *
015 *   *  Neither the name of the University of Southampton nor the names of its
016 *      contributors may be used to endorse or promote products derived from this
017 *      software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
026 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package org.openimaj.tools.similaritymatrix.modes;
031
032import java.io.BufferedWriter;
033import java.io.File;
034import java.io.FileWriter;
035import java.util.Set;
036
037import org.jgrapht.UndirectedGraph;
038import org.jgrapht.graph.DefaultEdge;
039import org.jgrapht.graph.UndirectedSubgraph;
040import org.openimaj.math.graph.algorithm.CharikarDensestSubgraph;
041import org.openimaj.math.matrix.similarity.SimilarityMatrix;
042
043public class DensestSubgraph extends ThresholdOption implements ToolMode {
044        @Override
045        public void process(SimilarityMatrix matrix, File output) throws Exception {
046                UndirectedGraph<String, DefaultEdge> graph = matrix.toUndirectedUnweightedGraph(threshold);
047                
048                CharikarDensestSubgraph<String, DefaultEdge> estimator = new CharikarDensestSubgraph<String, DefaultEdge>(graph);
049                UndirectedSubgraph<String, DefaultEdge> subgraph = estimator.getDensestSubgraph();
050                
051                System.out.println("Density is " + CharikarDensestSubgraph.calculateDensity(subgraph));
052                
053                Set<String> vertices = subgraph.vertexSet();
054                
055                if (output == null) {
056                        for (String s : vertices) System.out.println(s);
057                } else { 
058                        BufferedWriter bw = new BufferedWriter(new FileWriter(output));
059                        for (String s : vertices) bw.append(s + "\n");
060                        bw.close();
061                }
062        }
063}