org.dkpro.tc.ml.weka.writer.WekaFeatureEncoder Maven / Gradle / Ivy

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/**
 * Copyright 2018
 * Ubiquitous Knowledge Processing (UKP) Lab
 * Technische Universität Darmstadt
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see http://www.gnu.org/licenses/.
 */
package org.dkpro.tc.ml.weka.writer;

import java.util.ArrayList;
import java.util.Collection;

import org.dkpro.tc.api.exception.TextClassificationException;
import org.dkpro.tc.api.features.Feature;
import org.dkpro.tc.api.features.FeatureType;
import org.dkpro.tc.api.features.Instance;
import org.dkpro.tc.ml.weka.util.AttributeStore;

import weka.core.Attribute;
import weka.core.Utils;

/*
 * Converts the TC feature representation into the Weka representation.
 * 
 * Copyright (c) 2012, Regents of the University of Colorado 

 * All rights reserved.
 */
public class WekaFeatureEncoder
{

    public static AttributeStore getAttributeStore(Collection instances)
        throws TextClassificationException
    {
        AttributeStore attributeStore = new AttributeStore();

        for (Instance instance : instances) {
            for (Feature feature : instance.getFeatures()) {
                if (!attributeStore.containsAttributeName(feature.getName())) {
                    Attribute attribute = featureToAttribute(feature);
                    attributeStore.addAttribute(feature.getName(), attribute);
                }
            }
        }

        return attributeStore;
    }

    public static Attribute featureToAttributeUsingFeatureDescription(String featureName,
            FeatureType value, String enumType)
        throws TextClassificationException
    {
        String name = Utils.quote(featureName);
        Attribute attribute;
        // if value is a number then create a numeric attribute
        if (value.equals(FeatureType.NUMERIC) || value.equals(FeatureType.BOOLEAN)) {
            attribute = new Attribute(name);
        }
        else if (value.equals(FeatureType.STRING)) {
            attribute = new Attribute(name, true);
        }
        // if value is an Enum thene create a nominal attribute
        else if (value.equals(FeatureType.NOMINAL)) {
            Class forName = null;
            try {
                forName = Class.forName(enumType);
            }
            catch (ClassNotFoundException e) {
                throw new TextClassificationException(e);
            }
            Object[] enumConstants = forName.getEnumConstants();
            ArrayList attributeValues = new ArrayList(enumConstants.length);
            for (Object enumConstant : enumConstants) {
                attributeValues.add(enumConstant.toString());
            }
            attribute = new Attribute(name, attributeValues);
        }
        else {
            attribute = new Attribute(name, (ArrayList) null);
        }
        return attribute;
    }

    public static Attribute featureToAttribute(Feature feature) throws TextClassificationException
    {
        String name = Utils.quote(feature.getName());
        Object value = feature.getValue();
        Attribute attribute;
        // if value is a number then create a numeric attribute
        if (value instanceof Number) {
            attribute = new Attribute(name);
        } // if value is a boolean then create a numeric attribute
        else if (value instanceof Boolean) {
            attribute = new Attribute(name);
        }
        // if value is an Enum thene create a nominal attribute
        else if (value instanceof Enum) {
            Object[] enumConstants = value.getClass().getEnumConstants();
            ArrayList attributeValues = new ArrayList(enumConstants.length);
            for (Object enumConstant : enumConstants) {
                attributeValues.add(enumConstant.toString());
            }
            attribute = new Attribute(name, attributeValues);
        }
        else {
            attribute = new Attribute(name, (ArrayList) null);
        }
        return attribute;
    }

}