complexlearner.java

Boosting算法软件包

package jboost;

import java.util.Vector;

import jboost.booster.AbstractBooster;
import jboost.booster.Booster;
import jboost.controller.Configuration;
import jboost.examples.Example;
import jboost.learner.SplitterBuilder;

/** 
 * A complex learner that generates a classifier which
 * combines many base classifiers.  The responsibility of a complex
 * learner is to suggest candidate base classifiers to add to the
 * current rule and to add base classifiers as directed. As a final
 * result, it gives the generated complex classifier.
 *
 * For now, do not assume that this combined classifier and the complex learner are 
 * disjoint. 
 * In other words, they may share nodes in common, and if the complex learner modifies 
 * a node then it will also be modified in the combined classifier.
 *
 * @version $Header: /cvsroot/jboost/jboost/src/jboost/ComplexLearner.java,v 1.1.1.1 2007/05/16 04:06:02 aarvey Exp $
 * @author Yoav Freund 									*/
public abstract class ComplexLearner {
    
    /** Generate a list of candidates */
    public abstract Vector getCandidates() throws NotSupportedException ;
    
    /** Add a CandidateSplit */
    public abstract void addCandidate(CandidateSplit candidate) 
	throws jboost.atree.InstrumentException;
    
    /** Gets a (base) Predictor corresponding to the candidate that was just
     *  added using addCandidate().
     */
    public abstract Predictor getLastBasePredictor();

    /** Add an example to the internal data structures */
    public abstract void addExample(Example e);
    
    /** Signify that all examples have been added */
    public abstract void finalizeData();
    
    /** Reset all the learning infrastructure and internal data
        structures.  */

    public abstract void resetData();

    /** Extract the combined p redictor.  */
    public abstract WritablePredictor getCombinedPredictor();
    
    /** Main Factory Method - generates a complex learner with an empty 
	initial preditor */
    public static final ComplexLearner 
	generateLearner(Booster booster, 
			SplitterBuilder[] sb, 
			Configuration config)
    {return null;}		// to be implemented

    /** Instrumentation Factory - generates a comlex learner with a
	given predictor as its initial predictor */
    public static final ComplexLearner 
	instrumentPredictor(Predictor predictor,
			     Booster booster, 
			     SplitterBuilder[] sb, 
			     Configuration config) 
    {return null;}		// to be implemented

   /** Modify the predictions of previously added base rules */
    public void adjustPredictions() {}


    protected boolean isFinalized;
}