/*
* 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.
*/
/*
* AbstractClusterer.java
* Copyright (C) 1999 University of Waikato, Hamilton, New Zealand
*
*/
package weka.clusterers;
import weka.core.Capabilities;
import weka.core.CapabilitiesHandler;
import weka.core.Instance;
import weka.core.Instances;
import weka.core.RevisionHandler;
import weka.core.RevisionUtils;
import weka.core.SerializedObject;
import weka.core.Utils;
import weka.core.Capabilities.Capability;
import java.io.Serializable;
/**
* Abstract clusterer.
*
* @author Mark Hall (mhall@cs.waikato.ac.nz)
* @version $Revision: 6624 $
*/
public abstract class AbstractClusterer
implements Clusterer, Cloneable, Serializable, CapabilitiesHandler, RevisionHandler {
/** for serialization */
private static final long serialVersionUID = -6099962589663877632L;
// ===============
// Public methods.
// ===============
/**
* Generates a clusterer. Has to initialize all fields of the clusterer
* that are not being set via options.
*
* @param data set of instances serving as training data
* @exception Exception if the clusterer has not been
* generated successfully
*/
public abstract void buildClusterer(Instances data) throws Exception;
/**
* Classifies a given instance. Either this or distributionForInstance()
* needs to be implemented by subclasses.
*
* @param instance the instance to be assigned to a cluster
* @return the number of the assigned cluster as an integer
* @exception Exception if instance could not be clustered
* successfully
*/
public int clusterInstance(Instance instance) throws Exception {
double [] dist = distributionForInstance(instance);
if (dist == null) {
throw new Exception("Null distribution predicted");
}
if (Utils.sum(dist) <= 0) {
throw new Exception("Unable to cluster instance");
}
return Utils.maxIndex(dist);
}
/**
* Predicts the cluster memberships for a given instance. Either
* this or clusterInstance() needs to be implemented by subclasses.
*
* @param instance the instance to be assigned a cluster.
* @return an array containing the estimated membership
* probabilities of the test instance in each cluster (this
* should sum to at most 1)
* @exception Exception if distribution could not be
* computed successfully
*/
public double[] distributionForInstance(Instance instance)
throws Exception {
double[] d = new double[numberOfClusters()];
d[clusterInstance(instance)] = 1.0;
return d;
}
/**
* Returns the number of clusters.
*
* @return the number of clusters generated for a training dataset.
* @exception Exception if number of clusters could not be returned
* successfully
*/
public abstract int numberOfClusters() throws Exception;
/**
* Creates a new instance of a clusterer given it's class name and
* (optional) arguments to pass to it's setOptions method. If the
* clusterer implements OptionHandler and the options parameter is
* non-null, the clusterer will have it's options set.
*
* @param clustererName the fully qualified class name of the clusterer
* @param options an array of options suitable for passing to setOptions. May
* be null.
* @return the newly created search object, ready for use.
* @exception Exception if the clusterer class name is invalid, or the
* options supplied are not acceptable to the clusterer.
*/
public static Clusterer forName(String clustererName,
String [] options) throws Exception {
return (Clusterer)Utils.forName(Clusterer.class,
clustererName,
options);
}
/**
* Creates a deep copy of the given clusterer using serialization.
*
* @param model the clusterer to copy
* @return a deep copy of the clusterer
* @exception Exception if an error occurs
*/
public static Clusterer makeCopy(Clusterer model) throws Exception {
return (Clusterer) new SerializedObject(model).getObject();
}
/**
* Creates copies of the current clusterer. Note that this method
* now uses Serialization to perform a deep copy, so the Clusterer
* object must be fully Serializable. Any currently built model will
* now be copied as well.
*
* @param model an example clusterer to copy
* @param num the number of clusterer copies to create.
* @return an array of clusterers.
* @exception Exception if an error occurs
*/
public static Clusterer [] makeCopies(Clusterer model,
int num) throws Exception {
if (model == null) {
throw new Exception("No model clusterer set");
}
Clusterer [] clusterers = new Clusterer [num];
SerializedObject so = new SerializedObject(model);
for(int i = 0; i < clusterers.length; i++) {
clusterers[i] = (Clusterer) so.getObject();
}
return clusterers;
}
/**
* Returns the Capabilities of this clusterer. Derived classifiers have to
* override this method to enable capabilities.
*
* @return the capabilities of this object
* @see Capabilities
*/
public Capabilities getCapabilities() {
Capabilities result;
result = new Capabilities(this);
result.enableAll();
// result.enable(Capability.NO_CLASS);
return result;
}
/**
* Returns the revision string.
*
* @return the revision
*/
public String getRevision() {
return RevisionUtils.extract("$Revision: 6624 $");
}
/**
* runs the clusterer instance with the given options.
*
* @param clusterer the clusterer to run
* @param options the commandline options
*/
public static void runClusterer(Clusterer clusterer, String[] options) {
try {
System.out.println(ClusterEvaluation.evaluateClusterer(clusterer, options));
}
catch (Exception e) {
if ( (e.getMessage() == null)
|| ( (e.getMessage() != null)
&& (e.getMessage().indexOf("General options") == -1) ) )
e.printStackTrace();
else
System.err.println(e.getMessage());
}
}
}