001/** 
002 * Copyright (c) 2009, Regents of the University of Colorado 
003 * All rights reserved.
004 * 
005 * Redistribution and use in source and binary forms, with or without
006 * modification, are permitted provided that the following conditions are met:
007 * 
008 * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 
009 * 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. 
010 * Neither the name of the University of Colorado at Boulder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. 
011 * 
012 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
013 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
014 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
015 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
016 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
017 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
018 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
019 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
020 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
021 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
022 * POSSIBILITY OF SUCH DAMAGE. 
023 */
024package org.cleartk.token.pos.impl;
025
026import java.util.ArrayList;
027import java.util.List;
028
029import org.apache.uima.UimaContext;
030import org.apache.uima.jcas.JCas;
031import org.apache.uima.resource.ResourceInitializationException;
032import org.cleartk.ml.Feature;
033import org.cleartk.ml.feature.extractor.CleartkExtractor;
034import org.cleartk.ml.feature.extractor.CleartkExtractorException;
035import org.cleartk.ml.feature.extractor.CoveredTextExtractor;
036import org.cleartk.ml.feature.extractor.FeatureExtractor1;
037import org.cleartk.ml.feature.extractor.CleartkExtractor.Following;
038import org.cleartk.ml.feature.extractor.CleartkExtractor.Ngram;
039import org.cleartk.ml.feature.extractor.CleartkExtractor.Preceding;
040import org.cleartk.ml.feature.function.CapitalTypeFeatureFunction;
041import org.cleartk.ml.feature.function.CharacterNgramFeatureFunction;
042import org.cleartk.ml.feature.function.FeatureFunctionExtractor;
043import org.cleartk.ml.feature.function.LowerCaseFeatureFunction;
044import org.cleartk.ml.feature.function.NumericTypeFeatureFunction;
045import org.cleartk.token.pos.PosFeatureExtractor;
046import org.cleartk.token.type.Sentence;
047import org.cleartk.token.type.Token;
048import org.apache.uima.fit.factory.initializable.Initializable;
049
050import com.google.common.collect.Lists;
051
052/**
053 * <br>
054 * Copyright (c) 2009, Regents of the University of Colorado <br>
055 * All rights reserved.
056 * 
057 * @author Philip Ogren
058 * 
059 */
060
061public class DefaultFeatureExtractor implements PosFeatureExtractor<Token, Sentence>, Initializable {
062
063  private List<FeatureExtractor1<Token>> simpleExtractors;
064
065  private List<CleartkExtractor<Token, Token>> windowExtractors;
066
067  private List<CleartkExtractor<Token, Token>> windowNGramExtractors;
068
069  public void initialize(UimaContext context) throws ResourceInitializationException {
070    simpleExtractors = Lists.newArrayList();
071
072    FeatureExtractor1<Token> wordExtractor = new CoveredTextExtractor<Token>();
073
074    CharacterNgramFeatureFunction.Orientation fromLeft = CharacterNgramFeatureFunction.Orientation.LEFT_TO_RIGHT;
075    CharacterNgramFeatureFunction.Orientation fromRight = CharacterNgramFeatureFunction.Orientation.RIGHT_TO_LEFT;
076    simpleExtractors.add(new FeatureFunctionExtractor<Token>(
077        wordExtractor,
078        new LowerCaseFeatureFunction(),
079        new CapitalTypeFeatureFunction(),
080        new NumericTypeFeatureFunction(),
081        new CharacterNgramFeatureFunction(fromLeft, 0, 1),
082        new CharacterNgramFeatureFunction(fromLeft, 0, 2),
083        new CharacterNgramFeatureFunction(fromLeft, 0, 3),
084        new CharacterNgramFeatureFunction(fromRight, 0, 1),
085        new CharacterNgramFeatureFunction(fromRight, 0, 2),
086        new CharacterNgramFeatureFunction(fromRight, 0, 3),
087        new CharacterNgramFeatureFunction(fromRight, 0, 4),
088        new CharacterNgramFeatureFunction(fromRight, 0, 5),
089        new CharacterNgramFeatureFunction(fromRight, 0, 6)));
090
091    windowExtractors = Lists.newArrayList();
092    windowExtractors.add(new CleartkExtractor<Token, Token>(
093        Token.class,
094        wordExtractor,
095        new Preceding(2),
096        new Following(2)));
097
098    windowNGramExtractors = Lists.newArrayList();
099    windowNGramExtractors.add(new CleartkExtractor<Token, Token>(Token.class, wordExtractor, new Ngram(
100        new Preceding(2)), new Ngram(new Following(2))));
101  }
102
103  public List<Feature> extractFeatures(JCas jCas, Token token, Sentence sentence)
104      throws CleartkExtractorException {
105    List<Feature> features = new ArrayList<Feature>();
106
107    for (FeatureExtractor1<Token> extractor : simpleExtractors) {
108      features.addAll(extractor.extract(jCas, token));
109    }
110
111    for (CleartkExtractor<Token, Token> extractor : windowExtractors) {
112      features.addAll(extractor.extractWithin(jCas, token, sentence));
113    }
114
115    for (CleartkExtractor<Token, Token> extractor : windowNGramExtractors) {
116      features.addAll(extractor.extractWithin(jCas, token, sentence));
117    }
118
119    return features;
120  }
121
122}