adams.gui.visualization.debug.objectexport.WekaInstancesExporter.java Source code

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Here is the source code for adams.gui.visualization.debug.objectexport.WekaInstancesExporter.java

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/*
 *   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/>.
 */

/**
 * WekaInstancesExporter.java
 * Copyright (C) 2015 University of Waikato, Hamilton, NZ
 */

package adams.gui.visualization.debug.objectexport;

import adams.core.Utils;
import nz.ac.waikato.cms.locator.ClassLocator;
import weka.core.Instance;
import weka.core.Instances;
import weka.core.converters.ArffSaver;
import weka.core.converters.ConverterUtils.DataSink;

import java.io.File;

/**
 * Exports Weka Instances/Instance objects.
 *
 * @author FracPete (fracpete at waikato dot ac dot nz)
 * @version $Revision$
 */
public class WekaInstancesExporter extends AbstractObjectExporter {

    private static final long serialVersionUID = 4899389310274830738L;

    /**
     * Returns a string describing the format (used in the file chooser).
     *
     * @return          a description suitable for displaying in the
     *             file chooser
     */
    public String getFormatDescription() {
        return "ARFF files";
    }

    /**
     * Returns the extension(s) of the format.
     *
     * @return          the extension (without the dot!)
     */
    public String[] getFormatExtensions() {
        return new ArffSaver().getFileExtensions();
    }

    /**
     * Checks whether the exporter can handle the specified class.
     *
     * @param cls      the class to check
     * @return      true if the exporter can handle this type of object
     */
    @Override
    public boolean handles(Class cls) {
        return (ClassLocator.isSubclass(Instances.class, cls)) || (ClassLocator.hasInterface(Instance.class, cls));
    }

    /**
     * Performs the actual export.
     *
     * @param obj      the object to export
     * @param file   the file to export to
     * @return      null if successful, otherwise error message
     */
    @Override
    protected String doExport(Object obj, File file) {
        Instances data;
        Instance inst;

        try {
            if (obj instanceof Instances) {
                DataSink.write(file.getAbsolutePath(), (Instances) obj);
                return null;
            } else {
                inst = (Instance) obj;
                if (inst.dataset() != null) {
                    data = new Instances(inst.dataset());
                    data.add((Instance) inst.copy());
                    DataSink.write(file.getAbsolutePath(), data);
                    return null;
                } else {
                    return "Instance has no dataset associated, cannot export as ARFF!";
                }
            }
        } catch (Exception e) {
            return "Failed to write Instances to '" + file + "'!\n" + Utils.throwableToString(e);
        }
    }
}