weka.filters.unsupervised.instance.SparseToNonSparse.java Source code

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Here is the source code for weka.filters.unsupervised.instance.SparseToNonSparse.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/>.
 */

/*
 *    SparseToNonSparse.java
 *    Copyright (C) 2002-2012 University of Waikato, Hamilton, New Zealand
 *
 */

package weka.filters.unsupervised.instance;

import weka.core.*;
import weka.core.Capabilities.Capability;
import weka.filters.Filter;
import weka.filters.StreamableFilter;
import weka.filters.UnsupervisedFilter;

/** 
 <!-- globalinfo-start -->
 * An instance filter that converts all incoming sparse instances into non-sparse format.
 * <p/>
 <!-- globalinfo-end -->
 * 
 * @author Len Trigg (len@reeltwo.com)
 * @version $Revision$ 
 */
public class SparseToNonSparse extends Filter
        implements UnsupervisedFilter, StreamableFilter, WeightedAttributesHandler, WeightedInstancesHandler {

    /** for serialization */
    static final long serialVersionUID = 2481634184210236074L;

    /**
     * Returns a string describing this filter
     *
     * @return a description of the filter suitable for
     * displaying in the explorer/experimenter gui
     */
    public String globalInfo() {
        return "An instance filter that converts all incoming sparse instances" + " into non-sparse format.";
    }

    /** 
     * Returns the Capabilities of this filter.
     *
     * @return            the capabilities of this object
     * @see               Capabilities
     */
    public Capabilities getCapabilities() {
        Capabilities result = super.getCapabilities();
        result.disableAll();

        // attributes
        result.enableAllAttributes();
        result.enable(Capability.MISSING_VALUES);

        // class
        result.enableAllClasses();
        result.enable(Capability.MISSING_CLASS_VALUES);
        result.enable(Capability.NO_CLASS);

        return result;
    }

    /**
     * Sets the format of the input instances.
     *
     * @param instanceInfo an Instances object containing the input instance
     * structure (any instances contained in the object are ignored - only the
     * structure is required).
     * @return true if the outputFormat may be collected immediately
     * @throws Exception if format cannot be processed
     */
    public boolean setInputFormat(Instances instanceInfo) throws Exception {

        super.setInputFormat(instanceInfo);
        setOutputFormat(instanceInfo);
        return true;
    }

    /**
     * Input an instance for filtering. Ordinarily the instance is processed
     * and made available for output immediately. Some filters require all
     * instances be read before producing output.
     *
     * @param instance the input instance
     * @return true if the filtered instance may now be
     * collected with output().
     * @throws IllegalStateException if no input structure has been defined
     */
    public boolean input(Instance instance) {

        if (getInputFormat() == null) {
            throw new IllegalStateException("No input instance format defined");
        }
        if (m_NewBatch) {
            resetQueue();
            m_NewBatch = false;
        }
        Instance inst = null;
        if (instance instanceof SparseInstance) {
            inst = new DenseInstance(instance.weight(), instance.toDoubleArray());
            inst.setDataset(instance.dataset());
        } else {
            inst = (Instance) instance.copy();
        }
        push(inst, false); // No need to copy instance
        return true;
    }

    /**
     * Returns the revision string.
     * 
     * @return      the revision
     */
    public String getRevision() {
        return RevisionUtils.extract("$Revision$");
    }

    /**
     * Main method for testing this class.
     *
     * @param argv should contain arguments to the filter: use -h for help
     */
    public static void main(String[] argv) {
        runFilter(new SparseToNonSparse(), argv);
    }
}