SeqDecisionModel.java

package org.maltparser.parser.guide.decision;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import org.maltparser.core.exception.MaltChainedException;
import org.maltparser.core.feature.FeatureModel;
import org.maltparser.core.feature.FeatureVector;
import org.maltparser.core.syntaxgraph.DependencyStructure;
import org.maltparser.parser.DependencyParserConfig;
import org.maltparser.parser.guide.ClassifierGuide;
import org.maltparser.parser.guide.GuideException;
import org.maltparser.parser.guide.instance.AtomicModel;
import org.maltparser.parser.guide.instance.FeatureDivideModel;
import org.maltparser.parser.guide.instance.InstanceModel;
import org.maltparser.parser.history.action.GuideDecision;
import org.maltparser.parser.history.action.MultipleDecision;
import org.maltparser.parser.history.action.SingleDecision;
import org.maltparser.parser.history.container.TableContainer.RelationToNextDecision;

/**
 *
 * @author Johan Hall
 * @since 1.1
*
 */
public class SeqDecisionModel implements DecisionModel {

    private ClassifierGuide guide;
    private String modelName;
    private FeatureModel featureModel;
    private InstanceModel instanceModel;
    private int decisionIndex;
    private DecisionModel prevDecisionModel;
    private DecisionModel nextDecisionModel;
    private String branchedDecisionSymbols;

    public SeqDecisionModel(ClassifierGuide guide, FeatureModel featureModel) throws MaltChainedException {
        this.branchedDecisionSymbols = "";
        setGuide(guide);
        setFeatureModel(featureModel);
        setDecisionIndex(0);
        setModelName("sdm" + decisionIndex);
        setPrevDecisionModel(null);
    }

    public SeqDecisionModel(ClassifierGuide guide, DecisionModel prevDecisionModel, String branchedDecisionSymbol) throws MaltChainedException {
        if (branchedDecisionSymbol != null && branchedDecisionSymbol.length() > 0) {
            this.branchedDecisionSymbols = branchedDecisionSymbol;
        } else {
            this.branchedDecisionSymbols = "";
        }
        setGuide(guide);
        setFeatureModel(prevDecisionModel.getFeatureModel());
        setDecisionIndex(prevDecisionModel.getDecisionIndex() + 1);
        setPrevDecisionModel(prevDecisionModel);
        if (branchedDecisionSymbols != null && branchedDecisionSymbols.length() > 0) {
            setModelName("sdm" + decisionIndex + branchedDecisionSymbols);
        } else {
            setModelName("sdm" + decisionIndex);
        }
    }

    public void updateFeatureModel() throws MaltChainedException {
        featureModel.update();
    }

    public void finalizeSentence(DependencyStructure dependencyGraph) throws MaltChainedException {
        if (instanceModel != null) {
            instanceModel.finalizeSentence(dependencyGraph);
        }
        if (nextDecisionModel != null) {
            nextDecisionModel.finalizeSentence(dependencyGraph);
        }
    }

    public void noMoreInstances() throws MaltChainedException {
        if (guide.getGuideMode() == ClassifierGuide.GuideMode.CLASSIFY) {
            throw new GuideException("The decision model could not create it's model. ");
        }
        if (instanceModel != null) {
            instanceModel.noMoreInstances();
            instanceModel.train();
        }
        if (nextDecisionModel != null) {
            nextDecisionModel.noMoreInstances();
        }
    }

    public void terminate() throws MaltChainedException {
        if (instanceModel != null) {
            instanceModel.terminate();
            instanceModel = null;
        }
        if (nextDecisionModel != null) {
            nextDecisionModel.terminate();
            nextDecisionModel = null;
        }
    }

    public void addInstance(GuideDecision decision) throws MaltChainedException {
        if (decision instanceof SingleDecision) {
            throw new GuideException("A sequantial decision model expect a sequence of decisions, not a single decision. ");
        }
        featureModel.update();
        final SingleDecision singleDecision = ((MultipleDecision) decision).getSingleDecision(decisionIndex);
        if (instanceModel == null) {
            initInstanceModel(singleDecision.getTableContainer().getTableContainerName());
        }
        instanceModel.addInstance(singleDecision);
        if (singleDecision.continueWithNextDecision() && decisionIndex + 1 < decision.numberOfDecisions()) {
            if (nextDecisionModel == null) {
                initNextDecisionModel(((MultipleDecision) decision).getSingleDecision(decisionIndex + 1), branchedDecisionSymbols);
            }
            nextDecisionModel.addInstance(decision);
        }
    }

    public boolean predict(GuideDecision decision) throws MaltChainedException {
        if (decision instanceof SingleDecision) {
            throw new GuideException("A sequantial decision model expect a sequence of decisions, not a single decision. ");
        }
        featureModel.update();
        final SingleDecision singleDecision = ((MultipleDecision) decision).getSingleDecision(decisionIndex);
        if (instanceModel == null) {
            initInstanceModel(singleDecision.getTableContainer().getTableContainerName());
        }

        boolean success = instanceModel.predict(singleDecision);
        if (singleDecision.continueWithNextDecision() && decisionIndex + 1 < decision.numberOfDecisions()) {
            if (nextDecisionModel == null) {
                initNextDecisionModel(((MultipleDecision) decision).getSingleDecision(decisionIndex + 1), branchedDecisionSymbols);
            }
            success = nextDecisionModel.predict(decision) && success;
        }
        return success;
    }

    public FeatureVector predictExtract(GuideDecision decision) throws MaltChainedException {
        if (decision instanceof SingleDecision) {
            throw new GuideException("A sequantial decision model expect a sequence of decisions, not a single decision. ");
        }
        featureModel.update();
        final SingleDecision singleDecision = ((MultipleDecision) decision).getSingleDecision(decisionIndex);
        if (instanceModel == null) {
            initInstanceModel(singleDecision.getTableContainer().getTableContainerName());
        }

        FeatureVector fv = instanceModel.predictExtract(singleDecision);
        if (singleDecision.continueWithNextDecision() && decisionIndex + 1 < decision.numberOfDecisions()) {
            if (nextDecisionModel == null) {
                initNextDecisionModel(((MultipleDecision) decision).getSingleDecision(decisionIndex + 1), branchedDecisionSymbols);
            }
            nextDecisionModel.predictExtract(decision);
        }
        return fv;
    }

    public FeatureVector extract() throws MaltChainedException {
        featureModel.update();
        return instanceModel.extract(); // TODO handle many feature vectors
    }

    public boolean predictFromKBestList(GuideDecision decision) throws MaltChainedException {
        if (decision instanceof SingleDecision) {
            throw new GuideException("A sequantial decision model expect a sequence of decisions, not a single decision. ");
        }

        boolean success = false;
        final SingleDecision singleDecision = ((MultipleDecision) decision).getSingleDecision(decisionIndex);
        // TODO develop different strategies for resolving which kBestlist that should be used
        if (nextDecisionModel != null && singleDecision.continueWithNextDecision()) {
            success = nextDecisionModel.predictFromKBestList(decision);
        }
        if (!success) {
            success = singleDecision.updateFromKBestList();
            if (success && singleDecision.continueWithNextDecision() && decisionIndex + 1 < decision.numberOfDecisions()) {
                if (nextDecisionModel == null) {
                    initNextDecisionModel(((MultipleDecision) decision).getSingleDecision(decisionIndex + 1), branchedDecisionSymbols);
                }
                nextDecisionModel.predict(decision);
            }
        }
        return success;
    }

    public ClassifierGuide getGuide() {
        return guide;
    }

    public String getModelName() {
        return modelName;
    }

    public FeatureModel getFeatureModel() {
        return featureModel;
    }

    public int getDecisionIndex() {
        return decisionIndex;
    }

    public DecisionModel getPrevDecisionModel() {
        return prevDecisionModel;
    }

    public DecisionModel getNextDecisionModel() {
        return nextDecisionModel;
    }

    private void setPrevDecisionModel(DecisionModel prevDecisionModel) {
        this.prevDecisionModel = prevDecisionModel;
    }

    private void setNextDecisionModel(DecisionModel nextDecisionModel) {
        this.nextDecisionModel = nextDecisionModel;
    }

    private void setFeatureModel(FeatureModel featureModel) {
        this.featureModel = featureModel;
    }

    private void setDecisionIndex(int decisionIndex) {
        this.decisionIndex = decisionIndex;
    }

    private void setModelName(String modelName) {
        this.modelName = modelName;
    }

    private void setGuide(ClassifierGuide guide) {
        this.guide = guide;
    }

    private void initInstanceModel(String subModelName) throws MaltChainedException {
        FeatureVector fv = featureModel.getFeatureVector(branchedDecisionSymbols + "." + subModelName);
        if (fv == null) {
            fv = featureModel.getFeatureVector(subModelName);
        }
        if (fv == null) {
            fv = featureModel.getMainFeatureVector();
        }

        DependencyParserConfig c = guide.getConfiguration();

        if (c.getOptionValue("guide", "data_split_column").toString().length() == 0) {
            instanceModel = new AtomicModel(-1, fv, this);
        } else {
            instanceModel = new FeatureDivideModel(fv, this);
        }
    }

    private void initNextDecisionModel(SingleDecision decision, String branchedDecisionSymbol) throws MaltChainedException {
        Class<?> decisionModelClass = null;
        if (decision.getRelationToNextDecision() == RelationToNextDecision.SEQUANTIAL) {
            decisionModelClass = org.maltparser.parser.guide.decision.SeqDecisionModel.class;
        } else if (decision.getRelationToNextDecision() == RelationToNextDecision.BRANCHED) {
            decisionModelClass = org.maltparser.parser.guide.decision.BranchedDecisionModel.class;
        } else if (decision.getRelationToNextDecision() == RelationToNextDecision.NONE) {
            decisionModelClass = org.maltparser.parser.guide.decision.OneDecisionModel.class;
        }

        if (decisionModelClass == null) {
            throw new GuideException("Could not find an appropriate decision model for the relation to the next decision");
        }

        try {
            Class<?>[] argTypes = {org.maltparser.parser.guide.ClassifierGuide.class, org.maltparser.parser.guide.decision.DecisionModel.class,
                java.lang.String.class};
            Object[] arguments = new Object[3];
            arguments[0] = getGuide();
            arguments[1] = this;
            arguments[2] = branchedDecisionSymbol;
            Constructor<?> constructor = decisionModelClass.getConstructor(argTypes);
            setNextDecisionModel((DecisionModel) constructor.newInstance(arguments));
        } catch (NoSuchMethodException e) {
            throw new GuideException("The decision model class '" + decisionModelClass.getName() + "' cannot be initialized. ", e);
        } catch (InstantiationException e) {
            throw new GuideException("The decision model class '" + decisionModelClass.getName() + "' cannot be initialized. ", e);
        } catch (IllegalAccessException e) {
            throw new GuideException("The decision model class '" + decisionModelClass.getName() + "' cannot be initialized. ", e);
        } catch (InvocationTargetException e) {
            throw new GuideException("The decision model class '" + decisionModelClass.getName() + "' cannot be initialized. ", e);
        }
    }

    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder();
        sb.append(modelName).append(", ");
        sb.append(nextDecisionModel.toString());
        return sb.toString();
    }
}