lu.lippmann.cdb.datasetview.tasks.SupervisedFeatureSelectionWithDecisionTreeTask.java Source code

Introduction

Here is the source code for lu.lippmann.cdb.datasetview.tasks.SupervisedFeatureSelectionWithDecisionTreeTask.java

Source

/**
 * Copyright 2014-2016 LIST (Luxembourg Institute of Science and Technology), all right reserved.
 * Authorship : Olivier PARISOT, Yoanne DIDRY
 * Licensed under GNU General Public License version 3
 */
package lu.lippmann.cdb.datasetview.tasks;

import java.util.*;

import lu.lippmann.cdb.dt.*;
import lu.lippmann.cdb.dt.weka.J48DecisionTreeFactory;
import lu.lippmann.cdb.models.*;
import lu.lippmann.cdb.weka.WekaDataProcessingUtil;
import weka.core.*;

/**
 * Task.
 * 
 * @author the WP1 team
 */
public final class SupervisedFeatureSelectionWithDecisionTreeTask extends Task {
    //
    // Instance fields
    //

    /** */
    private final DecisionTreeFactory dtFactory;

    //
    // Constructors
    //

    /**
     * Constructor.
     */
    public SupervisedFeatureSelectionWithDecisionTreeTask() {
        this(true);
    }

    /**
     * Constructor.
     */
    public SupervisedFeatureSelectionWithDecisionTreeTask(final boolean pruned) {
        final double defaultValueConfidenceFactor = DecisionTreeHelper.LOW_CONFIDENCE_FACTOR;
        this.dtFactory = new J48DecisionTreeFactory(defaultValueConfidenceFactor, !pruned);
    }

    //
    // Instance methods
    //   

    /**
     * {@inheritDoc}
     */
    @Override
    String getName() {
        return "Simplify with pruned DT (superv.)";
    }

    /**
     * {@inheritDoc}
     */
    @Override
    String getIconPath() {
        return "menu/simplify.png";
    }

    /**
     * {@inheritDoc}
     */
    @Override
    Instances process0(final Instances dataSet) throws Exception {
        if (dataSet.classIndex() == -1)
            throw new Exception("Need a selected class!");

        final DecisionTree dt = dtFactory.buildCachedDecisionTree(dataSet);
        final Set<Integer> attrToKeep = new HashSet<Integer>();

        for (final CNode cn : dt.getGraphWithOperations().getVertices()) {
            final Attribute attribute = dataSet.attribute(cn.getName());
            if (attribute != null)
                attrToKeep.add(attribute.index());
        }
        attrToKeep.add(dataSet.classIndex());

        final int size = attrToKeep.size();
        final int[] array = new int[size];
        int i = 0;
        final Iterator<Integer> iter = attrToKeep.iterator();
        while (iter.hasNext()) {
            array[i] = iter.next().intValue();
            i++;
        }

        return WekaDataProcessingUtil.buildFilteredByAttributesDataSet(dataSet, array);
    }
}