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.experiment.evaluation.cluster.analyser;
031
032import gnu.trove.map.hash.TIntIntHashMap;
033
034import java.util.HashMap;
035import java.util.Map;
036
037import org.openimaj.util.pair.IntIntPair;
038
039/**
040 * Tools for {@link ClusterAnalyser} instances
041 * @author Sina Samangooei (ss@ecs.soton.ac.uk)
042 */
043public class ClusterAnalyserUtils{
044        /**
045         * Map index to cluster from cluster array
046         * @param clustered
047         * @return index to cluster
048         */
049        public static Map<Integer, Integer> invert(int[][] clustered) {
050                int cluster = 0;
051                Map<Integer, Integer> ret = new HashMap<Integer, Integer>();
052                for (int[] is : clustered) {
053                        for (int index : is) {
054                                ret.put(index, cluster);
055                        }
056                        cluster++;
057                }
058                return ret;
059        }
060
061        /**
062         * @param is
063         * @param invCor
064         * @return the cluster with the maximum
065         */
066        public static IntIntPair findMaxClassCount(int[] is, Map<Integer, Integer> invCor) {
067                TIntIntHashMap classCounts = new TIntIntHashMap();
068                int max = 0;
069                int c = 0;
070                for (int i : is) {
071                        Integer c_i = invCor.get(i);
072                        if(c_i == null) continue;
073                        int count = classCounts.adjustOrPutValue(c_i, 1, 1);
074                        if(count > max){
075                                max = count;
076                                c = c_i;
077                        }
078                }
079                return IntIntPair.pair(c, max);
080        }
081
082}