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.ml.clustering.assignment;
031
032/**
033 * The {@link HardAssigner} interface describes classes that assign a spatial
034 * point to a single cluster.
035 * 
036 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
037 * 
038 * @param <DATATYPE>
039 *            the primitive array datatype which represents a centroid of this
040 *            cluster.
041 * @param <DISTANCES>
042 *            primitive array datatype for recording distances between points
043 *            and cluster centroids.
044 * @param <DISTANCE_INDEX>
045 *            datatype for representing an <index, distance> pair.
046 */
047public interface HardAssigner<DATATYPE, DISTANCES, DISTANCE_INDEX> extends Assigner<DATATYPE> {
048        /**
049         * Assign data to a cluster.
050         * 
051         * @param data
052         *            the data.
053         * @return The cluster indices which the data was assigned to.
054         */
055        public abstract int[] assign(final DATATYPE[] data);
056
057        /**
058         * Assign a single point to a cluster.
059         * 
060         * @param data
061         *            datum to assign.
062         * 
063         * @return the cluster index.
064         */
065        public abstract int assign(final DATATYPE data);
066
067        /**
068         * Assign data to clusters. The results are returned in the indices and
069         * distances arrays. The return arrays must have the same length as the data
070         * array.
071         * 
072         * @param data
073         *            the data.
074         * @param indices
075         *            the cluster index for each data point.
076         * @param distances
077         *            the distance to the closest cluster for each data point.
078         */
079        public abstract void assignDistance(final DATATYPE[] data, int[] indices, DISTANCES distances);
080
081        /**
082         * Assign a single point to a cluster.
083         * 
084         * @param data
085         *            point to assign.
086         * 
087         * @return the cluster index and distance.
088         */
089        public abstract DISTANCE_INDEX assignDistance(final DATATYPE data);
090
091        /**
092         * The number of centroids or unique ids that can be generated.
093         * 
094         * @return The number of centroids or unique ids that can be generated.
095         */
096        public int size();
097}