variable.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) 2003 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. */

package edu.umass.cs.mallet.grmm;

import salvo.jesus.graph.VertexImpl;
import edu.umass.cs.mallet.base.types.Alphabet;
import edu.umass.cs.mallet.base.types.LabelAlphabet;



/**
 *  Class for a discrete random variable in a graphical model.
 *
 * Created: Thu Sep 18 09:32:25 2003
 *
 * @author <a href="mailto:[e-mail]">Charles Sutton</a>
 * @version $Id: Variable.java,v 1.1 2004/07/15 17:53:31 casutton Exp $
 */
public class Variable extends VertexImpl implements Comparable {

	private LabelAlphabet outcomes;

	private static int counter = 0;

	/**
	 * Creates a new variable with the given outcomes.
	 */
	public Variable (LabelAlphabet outs) {
		this.outcomes = outs;
		if (outs.size() < 1) {
			throw new IllegalArgumentException 
				("Attempt to create variable with "+outs.size()+" outcomes.");
		}
    setIndex();
  }

	public Variable (int numOutcomes) 
	{
		if (numOutcomes < 1) {
			throw new IllegalArgumentException 
				("Attempt to create variable with "+numOutcomes+" outcomes.");
		}
		
		outcomes = new LabelAlphabet ();
		/* Setup default outcomes */
		for (int i = 0; i < numOutcomes; i++) {
			outcomes.lookupIndex (new Integer (i));
		}
    setIndex();
  }


  private void setIndex()
  {
    setLabel ("VAR" + (counter++));
  }


  public int getNumOutcomes () {
		return outcomes.size();
	}

	public Object lookupOutcome (int i) {
		return outcomes.lookupObject (i);
	}

	public LabelAlphabet getLabelAlphabet ()
	{
		return outcomes;
	}

  public int compareTo(Object o)
  {
    /*
    Variable var = (Variable) o;
    return getLabel().compareTo (var.getLabel());
    */
    int index = hashCode();
    int index2 = ((Variable)o).hashCode();

    if (index == index2)
      return 0;
    else if (index < index2)
      return -1;
    else return 1;
    /**/
  }

}