Ejemplo n.º 1
0
  /** This is (mostly) copied from CRF4.java */
  public boolean[][] labelConnectionsIn(
      Alphabet outputAlphabet, InstanceList trainingSet, String start) {
    int numLabels = outputAlphabet.size();
    boolean[][] connections = new boolean[numLabels][numLabels];
    for (int i = 0; i < trainingSet.size(); i++) {
      Instance instance = trainingSet.getInstance(i);
      FeatureSequence output = (FeatureSequence) instance.getTarget();
      for (int j = 1; j < output.size(); j++) {
        int sourceIndex = outputAlphabet.lookupIndex(output.get(j - 1));
        int destIndex = outputAlphabet.lookupIndex(output.get(j));
        assert (sourceIndex >= 0 && destIndex >= 0);
        connections[sourceIndex][destIndex] = true;
      }
    }

    // Handle start state
    if (start != null) {
      int startIndex = outputAlphabet.lookupIndex(start);
      for (int j = 0; j < outputAlphabet.size(); j++) {
        connections[startIndex][j] = true;
      }
    }

    return connections;
  }
Ejemplo n.º 2
0
  public TestCRFPipe(String trainingFilename) throws IOException {

    ArrayList<Pipe> pipes = new ArrayList<Pipe>();

    PrintWriter out = new PrintWriter("test.out");

    int[][] conjunctions = new int[3][];
    conjunctions[0] = new int[] {-1};
    conjunctions[1] = new int[] {1};
    conjunctions[2] = new int[] {-2, -1};

    pipes.add(new SimpleTaggerSentence2TokenSequence());
    // pipes.add(new FeaturesInWindow("PREV-", -1, 1));
    // pipes.add(new FeaturesInWindow("NEXT-", 1, 2));
    pipes.add(new OffsetConjunctions(conjunctions));
    pipes.add(new TokenTextCharSuffix("C1=", 1));
    pipes.add(new TokenTextCharSuffix("C2=", 2));
    pipes.add(new TokenTextCharSuffix("C3=", 3));
    pipes.add(new RegexMatches("CAPITALIZED", Pattern.compile("^\\p{Lu}.*")));
    pipes.add(new RegexMatches("STARTSNUMBER", Pattern.compile("^[0-9].*")));
    pipes.add(new RegexMatches("HYPHENATED", Pattern.compile(".*\\-.*")));
    pipes.add(new RegexMatches("DOLLARSIGN", Pattern.compile("\\$.*")));
    pipes.add(new TokenFirstPosition("FIRSTTOKEN"));
    pipes.add(new TokenSequence2FeatureVectorSequence());
    pipes.add(new SequencePrintingPipe(out));

    Pipe pipe = new SerialPipes(pipes);

    InstanceList trainingInstances = new InstanceList(pipe);

    trainingInstances.addThruPipe(
        new LineGroupIterator(
            new BufferedReader(
                new InputStreamReader(new GZIPInputStream(new FileInputStream(trainingFilename)))),
            Pattern.compile("^\\s*$"),
            true));

    out.close();
  }
Ejemplo n.º 3
0
  public static CRF4 createCRF(File trainingFile, CRFInfo crfInfo) throws FileNotFoundException {
    Reader trainingFileReader = new FileReader(trainingFile);

    // Create a pipe that we can use to convert the training
    // file to a feature vector sequence.
    Pipe p = new SimpleTagger.SimpleTaggerSentence2FeatureVectorSequence();

    // The training file does contain tags (aka targets)
    p.setTargetProcessing(true);

    // Register the default tag with the pipe, by looking it up
    // in the targetAlphabet before we look up any other tag.
    p.getTargetAlphabet().lookupIndex(crfInfo.defaultLabel);

    // Create a new instancelist to hold the training data.
    InstanceList trainingData = new InstanceList(p);

    // Read in the training data.
    trainingData.add(new LineGroupIterator(trainingFileReader, Pattern.compile("^\\s*$"), true));

    // Create the CRF model.
    CRF4 crf = new CRF4(p, null);

    // Set various config options
    crf.setGaussianPriorVariance(crfInfo.gaussianVariance);
    crf.setTransductionType(crfInfo.transductionType);

    // Set up the model's states.
    if (crfInfo.stateInfoList != null) {
      Iterator stateIter = crfInfo.stateInfoList.iterator();
      while (stateIter.hasNext()) {
        CRFInfo.StateInfo state = (CRFInfo.StateInfo) stateIter.next();
        crf.addState(
            state.name,
            state.initialCost,
            state.finalCost,
            state.destinationNames,
            state.labelNames,
            state.weightNames);
      }
    } else if (crfInfo.stateStructure == CRFInfo.FULLY_CONNECTED_STRUCTURE)
      crf.addStatesForLabelsConnectedAsIn(trainingData);
    else if (crfInfo.stateStructure == CRFInfo.HALF_CONNECTED_STRUCTURE)
      crf.addStatesForHalfLabelsConnectedAsIn(trainingData);
    else if (crfInfo.stateStructure == CRFInfo.THREE_QUARTERS_CONNECTED_STRUCTURE)
      crf.addStatesForThreeQuarterLabelsConnectedAsIn(trainingData);
    else if (crfInfo.stateStructure == CRFInfo.BILABELS_STRUCTURE)
      crf.addStatesForBiLabelsConnectedAsIn(trainingData);
    else throw new RuntimeException("Unexpected state structure " + crfInfo.stateStructure);

    // Set up the weight groups.
    if (crfInfo.weightGroupInfoList != null) {
      Iterator wgIter = crfInfo.weightGroupInfoList.iterator();
      while (wgIter.hasNext()) {
        CRFInfo.WeightGroupInfo wg = (CRFInfo.WeightGroupInfo) wgIter.next();
        FeatureSelection fs =
            FeatureSelection.createFromRegex(
                crf.getInputAlphabet(), Pattern.compile(wg.featureSelectionRegex));
        crf.setFeatureSelection(crf.getWeightsIndex(wg.name), fs);
      }
    }

    // Train the CRF.
    crf.train(trainingData, null, null, null, crfInfo.maxIterations);

    return crf;
  }