classification.java

这是一个matlab的java实现。里面有许多内容。请大家慢慢捉摸。

/* Copyright (C) 2002 Univ. of Massachusetts Amherst, Computer Science Dept.
   This file is part of "MALLET" (MAchine Learning for LanguagE Toolkit).
   http://www.cs.umass.edu/~mccallum/mallet
   This software is provided under the terms of the Common Public License,
   version 1.0, as published by http://www.opensource.org.  For further
   information, see the file `LICENSE' included with this distribution. */




/** 
   @author Andrew McCallum <a href="mailto:[e-mail]">[e-mail]</a>
 */

package edu.umass.cs.mallet.base.classify;

import edu.umass.cs.mallet.base.types.Instance;
import edu.umass.cs.mallet.base.types.Labeling;
import edu.umass.cs.mallet.base.types.Labeling;
import edu.umass.cs.mallet.base.types.LabelVector;
import edu.umass.cs.mallet.base.classify.Classifier;

/**
 * The result of classifying a single instance.
 * Contains the instance, the classifier used, and the labeling the
 * classifier produced.
 * Also has methods for comparing the correct (true) label contained in the
 * target field of the instance with the one produced by the classifier.
 */
public class Classification
{
	Instance instance;
	Classifier classifier;
	Labeling labeling;

	public Classification (Instance instance, Classifier classifier,
												 Labeling labeling)
	{
		this.instance = instance;
		this.classifier = classifier;
		this.labeling = labeling;
	}

	public Instance getInstance ()
	{
		return instance;
	}

	public Classifier getClassifier ()
	{
		return classifier;
	}

	public Labeling getLabeling ()
	{
		return labeling;
	}

	public LabelVector getLabelVector ()
	{
		return labeling.toLabelVector();
	}

	public boolean bestLabelIsCorrect ()
	{
		Labeling correctLabeling = instance.getLabeling();
		if (correctLabeling == null)
			throw new IllegalStateException ("Instance has no label.");
		return (labeling.getBestLabel().equals (correctLabeling.getBestLabel()));
	}

	public double valueOfCorrectLabel ()
	{
		Labeling correctLabeling = instance.getLabeling();
		int correctLabelIndex = correctLabeling.getBestIndex();
		return labeling.value (correctLabelIndex);
	}

	public void print ()
	{
		// xxx Fix this.
		System.out.print (classifier.getClass().getName() + "(.");
		System.out.print (") = [");
		for (int i = 0; i < labeling.numLocations(); i++)
			System.out.print (labeling.labelAtLocation(i).toString()+"="+labeling.valueAtLocation(i)+" ");
		System.out.println ("]");
	}

}