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.text.nlp.namedentity;
031
032import java.util.ArrayList;
033import java.util.HashMap;
034import java.util.List;
035import java.util.Map;
036import java.util.Set;
037
038import org.openimaj.ml.annotation.ScoredAnnotation;
039import org.openimaj.text.nlp.namedentity.YagoEntityCandidateFinderFactory.YagoEntityCandidateFinder;
040import org.openimaj.text.nlp.namedentity.YagoEntityContextScorerFactory.YagoEntityContextScorer;
041import org.openimaj.text.nlp.namedentity.YagoEntityExactMatcherFactory.YagoEntityExactMatcher;
042
043/**
044 * {@link EntityAnnotator} wrapper for {@link YagoEntityExactMatcher}
045 * @author Laurence Willmore (lgw1e10@ecs.soton.ac.uk)
046 * @author Sina Samangooei (ss@ecs.soton.ac.uk)
047 */
048public class YagoEntityCompleteAnnotator extends EntityAnnotator {
049        private YagoEntityContextScorer contextScorer;
050        private YagoEntityCandidateFinder candidateFinder;
051        private int localContextBound = 20;
052
053        /**
054         * Default constructor.
055         * @param contextScorer
056         * @param candidateFinder
057         */
058        public YagoEntityCompleteAnnotator(YagoEntityContextScorer contextScorer,
059                        YagoEntityCandidateFinder candidateFinder) {
060                super();
061                this.contextScorer = contextScorer;
062                this.candidateFinder = candidateFinder;
063        }
064
065        @Override
066        public Set<HashMap<String, Object>> getAnnotations() {
067                // Intentionally blank
068                return null;
069        }
070
071        @Override
072        public List<ScoredAnnotation<HashMap<String, Object>>> annotate(
073                        List<String> tokens) {
074                ArrayList<ScoredAnnotation<HashMap<String, Object>>> result = new ArrayList<ScoredAnnotation<HashMap<String, Object>>>();
075                // Check if any candidates are found
076                List<List<NamedEntity>> candidates = candidateFinder
077                                .getCandidates(tokens);
078                // If none found, return an empty.
079                if (candidates.size() == 0) {
080                        return result;
081                }
082                // Use Context Scoring to disambiguate candidates
083                for (List<NamedEntity> can : candidates) {
084                        ArrayList<String> companies = new ArrayList<String>();
085                        for (NamedEntity ent : can) {
086                                companies.add(ent.rootName);
087                        }
088                        //get the localised context for each list of named Entities
089                        List<String> localContext = getLocalContext(tokens, can.get(0).startToken, can.get(0).stopToken);
090                        Map<NamedEntity, Float> contextScores = contextScorer
091                                        .getScoresForEntityList(companies, localContext);
092                        float topScore = 0;
093                        NamedEntity resEntity = null;
094                        for (NamedEntity entity : can) {
095                                if (contextScores.keySet().contains(entity)
096                                                && contextScores.get(entity) > topScore) {
097                                        resEntity = entity;
098                                        topScore = contextScores.get(entity);
099                                }
100                        }
101                        if (resEntity != null) {
102                                HashMap<String, Object> annotation = new HashMap<String, Object>();
103                                annotation.put(YagoEntityContextAnnotator.SCORE, topScore);
104                                annotation.put(YagoEntityContextAnnotator.URI, resEntity.rootName);
105                                annotation.put(YagoEntityContextAnnotator.START_TOKEN,
106                                                resEntity.startToken);
107                                annotation.put(YagoEntityContextAnnotator.END_TOKEN,
108                                                resEntity.stopToken);
109                                annotation.put(YagoEntityContextAnnotator.TYPE,
110                                                resEntity.type.toString());
111                                result.add(new ScoredAnnotation<HashMap<String, Object>>(
112                                                annotation, 1));
113                        }
114                }
115                return result;
116        }
117
118        private List<String> getLocalContext(List<String> tokens, int startToken,
119                        int stopToken) {
120                final int bottom = Math.max(0, startToken - localContextBound);
121                final int top = Math.min(tokens.size(), stopToken + localContextBound);
122                return tokens.subList(bottom, top);
123        }
124}