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.ml.encoder.features;
025
026import java.io.File;
027import java.io.IOException;
028import java.io.PrintWriter;
029import java.util.ArrayList;
030import java.util.List;
031
032import org.cleartk.ml.Feature;
033import org.cleartk.ml.encoder.CleartkEncoderException;
034import org.cleartk.ml.encoder.FeatureEncoderUtil;
035import org.cleartk.util.collection.CompressedStringBiMap;
036
037/**
038 * <br>
039 * Copyright (c) 2009, Regents of the University of Colorado <br>
040 * All rights reserved.
041 * 
042 * @author Philip Ogren
043 */
044
045public class NameNumberFeaturesEncoder extends
046    FeaturesEncoder_ImplBase<List<NameNumber>, NameNumber> {
047
048  private static final long serialVersionUID = 7508330794260661987L;
049
050  public static final String LOOKUP_FILE_NAME = "names-lookup.txt";
051
052  private CompressedStringBiMap csbm;
053
054  private boolean compressFeatures;
055
056  public boolean isCompressFeatures() {
057    return compressFeatures;
058  }
059
060  private boolean allowNewFeatures = true;
061
062  private boolean sortNameLookup;
063
064  public NameNumberFeaturesEncoder(boolean compressFeatures, boolean sortNameLookup) {
065    super();
066    this.compressFeatures = compressFeatures;
067    this.sortNameLookup = sortNameLookup;
068    if (compressFeatures) {
069      csbm = new CompressedStringBiMap();
070    }
071  }
072
073  public NameNumberFeaturesEncoder() {
074    this(false, false);
075  }
076
077  @Override
078  public List<NameNumber> encodeAll(Iterable<Feature> features) throws CleartkEncoderException {
079    List<NameNumber> returnValues = new ArrayList<NameNumber>();
080
081    for (Feature feature : features) {
082      for (NameNumber nameNumber : this.encode(feature)) {
083        nameNumber.name = compress(escape(nameNumber.name));
084        if (nameNumber.name != null) {
085          returnValues.add(nameNumber);
086        }
087      }
088    }
089    return returnValues;
090  }
091
092  @Override
093  public void finalizeFeatureSet(File outputDirectory) throws IOException {
094    this.allowNewFeatures = false;
095
096    if (compressFeatures) {
097      File lookupFile = new File(outputDirectory, LOOKUP_FILE_NAME);
098      PrintWriter writer = new PrintWriter(lookupFile);
099      csbm.write(writer, sortNameLookup);
100      writer.close();
101    }
102  }
103
104  private String escape(String string) {
105    return FeatureEncoderUtil.escape(string, new char[] { '=' });
106  }
107
108  private String compress(String featureString) {
109    if (compressFeatures) {
110      if (allowNewFeatures) {
111        return csbm.getOrGenerateKey(featureString);
112      } else {
113        return csbm.inverse().get(featureString);
114      }
115    }
116    return featureString;
117  }
118}