source: src/main/java/weka/clusterers/forOPTICSAndDBScan/DataObjects/EuclidianDataObject.java @ 4

/*
 *    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 2 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, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 *    Copyright (C) 2004
 *    & Matthias Schubert (schubert@dbs.ifi.lmu.de)
 *    & Zhanna Melnikova-Albrecht (melnikov@cip.ifi.lmu.de)
 *    & Rainer Holzmann (holzmann@cip.ifi.lmu.de)
 */

package weka.clusterers.forOPTICSAndDBScan.DataObjects;

import weka.clusterers.forOPTICSAndDBScan.Databases.Database;
import weka.core.Attribute;
import weka.core.Instance;
import weka.core.RevisionHandler;
import weka.core.RevisionUtils;
import weka.core.Utils;

import java.io.Serializable;

/**
 * <p>
 * EuclidianDataObject.java <br/>
 * Authors: Rainer Holzmann, Zhanna Melnikova-Albrecht, Matthias Schubert <br/>
 * Date: Aug 19, 2004 <br/>
 * Time: 5:50:22 PM <br/>
 * $ Revision 1.4 $ <br/>
 * </p>
 *
 * @author Matthias Schubert (schubert@dbs.ifi.lmu.de)
 * @author Zhanna Melnikova-Albrecht (melnikov@cip.ifi.lmu.de)
 * @author Rainer Holzmann (holzmann@cip.ifi.lmu.de)
 * @version $Revision: 5987 $
 */
public class EuclidianDataObject
    implements DataObject, Serializable, RevisionHandler {

    /** for serialization */
    private static final long serialVersionUID = -4408119914898291075L;

    /**
     * Holds the original instance
     */
    private Instance instance;

    /**
     * Holds the (unique) key that is associated with this DataObject
     */
    private String key;

    /**
     * Holds the ID of the cluster, to which this DataObject is assigned
     */
    private int clusterID;

    /**
     * Holds the status for this DataObject (true, if it has been processed, else false)
     */
    private boolean processed;

    /**
     * Holds the coreDistance for this DataObject
     */
    private double c_dist;

    /**
     * Holds the reachabilityDistance for this DataObject
     */
    private double r_dist;

    /**
     * Holds the database, that is the keeper of this DataObject
     */
    private Database database;

    // *****************************************************************************************************************
    // constructors
    // *****************************************************************************************************************

    /**
     * Constructs a new DataObject. The original instance is kept as instance-variable
     * @param originalInstance the original instance
     */
    public EuclidianDataObject(Instance originalInstance, String key, Database database) {
        this.database = database;
        this.key = key;
        instance = originalInstance;
        clusterID = DataObject.UNCLASSIFIED;
        processed = false;
        c_dist = DataObject.UNDEFINED;
        r_dist = DataObject.UNDEFINED;
    }

    // *****************************************************************************************************************
    // methods
    // *****************************************************************************************************************

    /**
     * Compares two DataObjects in respect to their attribute-values
     * @param dataObject The DataObject, that is compared with this.dataObject
     * @return Returns true, if the DataObjects correspond in each value, else returns false
     */
    public boolean equals(DataObject dataObject) {
        if (this == dataObject) return true;
        if (!(dataObject instanceof EuclidianDataObject)) return false;

        final EuclidianDataObject euclidianDataObject = (EuclidianDataObject) dataObject;

        if (getInstance().equalHeaders(euclidianDataObject.getInstance())) {
            for (int i = 0; i < getInstance().numValues(); i++) {
                double i_value_Instance_1 = getInstance().valueSparse(i);
                double i_value_Instance_2 = euclidianDataObject.getInstance().valueSparse(i);

                if (i_value_Instance_1 != i_value_Instance_2) return false;
            }
            return true;
        }
        return false;
    }

    /**
     * Calculates the euclidian-distance between dataObject and this.dataObject
     * @param dataObject The DataObject, that is used for distance-calculation with this.dataObject
     * @return double-value The euclidian-distance between dataObject and this.dataObject
     *                      NaN, if the computation could not be performed
     */
    public double distance(DataObject dataObject) {
        double dist = 0.0;

        if (!(dataObject instanceof EuclidianDataObject)) return Double.NaN;

        if (getInstance().equalHeaders(dataObject.getInstance())) {
            for (int i = 0; i < getInstance().numValues(); i++) {
                double cDistance = computeDistance(getInstance().index(i),
                        getInstance().valueSparse(i),
                        dataObject.getInstance().valueSparse(i));
                dist += Math.pow(cDistance, 2.0);
            }
            return Math.sqrt(dist);
        }
        return Double.NaN;
    }

    /**
     * Performs euclidian-distance-calculation between two given values
     * @param index of the attribute within the DataObject's instance
     * @param v value_1
     * @param v1 value_2
     * @return double norm-distance between value_1 and value_2
     */
    private double computeDistance(int index, double v, double v1) {
        switch (getInstance().attribute(index).type()) {
            case Attribute.NOMINAL:
                return (Utils.isMissingValue(v) || Utils.isMissingValue(v1)
                        || ((int) v != (int) v1)) ? 1 : 0;

            case Attribute.NUMERIC:
                if (Utils.isMissingValue(v) || Utils.isMissingValue(v1)) {
                    if (Utils.isMissingValue(v) && Utils.isMissingValue(v1))
                        return 1;
                    else {
                        return (Utils.isMissingValue(v)) ? norm(v1, index)
                                : norm(v, index);
                    }
                } else
                    return norm(v, index) - norm(v1, index);

            default:
                return 0;
        }
    }

    /**
     * Normalizes a given value of a numeric attribute.
     *
     * @param x the value to be normalized
     * @param i the attribute's index
     */
    private double norm(double x, int i) {
        if (Double.isNaN(database.getAttributeMinValues()[i])
                || Utils.eq(database.getAttributeMaxValues()[i], database.getAttributeMinValues()[i])) {
            return 0;
        } else {
            return (x - database.getAttributeMinValues()[i]) /
                    (database.getAttributeMaxValues()[i] - database.getAttributeMinValues()[i]);
        }
    }

    /**
     * Returns the original instance
     * @return originalInstance
     */
    public Instance getInstance() {
        return instance;
    }

    /**
     * Returns the key for this DataObject
     * @return key
     */
    public String getKey() {
        return key;
    }

    /**
     * Sets the key for this DataObject
     * @param key The key is represented as string
     */
    public void setKey(String key) {
        this.key = key;
    }

    /**
     * Sets the clusterID (cluster), to which this DataObject belongs to
     * @param clusterID Number of the Cluster
     */
    public void setClusterLabel(int clusterID) {
        this.clusterID = clusterID;
    }

    /**
     * Returns the clusterID, to which this DataObject belongs to
     * @return clusterID
     */
    public int getClusterLabel() {
        return clusterID;
    }

    /**
     * Marks this dataObject as processed
     * @param processed True, if the DataObject has been already processed, false else
     */
    public void setProcessed(boolean processed) {
        this.processed = processed;
    }

    /**
     * Gives information about the status of a dataObject
     * @return True, if this dataObject has been processed, else false
     */
    public boolean isProcessed() {
        return processed;
    }

    /**
     * Sets a new coreDistance for this dataObject
     * @param c_dist coreDistance
     */
    public void setCoreDistance(double c_dist) {
        this.c_dist = c_dist;
    }

    /**
     * Returns the coreDistance for this dataObject
     * @return coreDistance
     */
    public double getCoreDistance() {
        return c_dist;
    }

    /**
     * Sets a new reachability-distance for this dataObject
     */
    public void setReachabilityDistance(double r_dist) {
        this.r_dist = r_dist;
    }

    /**
     * Returns the reachabilityDistance for this dataObject
     */
    public double getReachabilityDistance() {
        return r_dist;
    }

    public String toString() {
        return instance.toString();
    }
    
    /**
     * Returns the revision string.
     * 
     * @return          the revision
     */
    public String getRevision() {
      return RevisionUtils.extract("$Revision: 5987 $");
    }
}