assignment.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 edu.umass.cs.mallet.base.types.Alphabet;
import gnu.trove.TIntArrayList;
import java.util.ArrayList;



/**
 *  An assignment to a bunch of variables.
 *
 *  Note that outcomes are always integers.  If you
 *   want them to be something else, then the Variables
 *   all have outcome Alphabets; for example, see
 *  {@link Variable#lookupOutcome}.
 *
 * Created: Tue Oct 21 15:11:11 2003
 *
 * @author <a href="mailto:[e-mail]">Charles Sutton</a>
 * @version $Id: Assignment.java,v 1.1 2004/07/15 17:53:31 casutton Exp $
 */
public class Assignment {
	
	/* Maps from vars => indicies */
	Alphabet varMap;
 
	/* Maps from indices => outcomes. */
	TIntArrayList values;

	/** Creates an empty assignment. */
	public Assignment() 
	{
		varMap = new Alphabet (Variable.class);
		values = new TIntArrayList ();
	} 

	public Assignment (Variable var, int outcome)
	{
		this();
		setValue (var, outcome);
	}

	/** Creates an assignemnt for the given variables. */
	public Assignment (Variable[] vars, int[] outcomes) 
	{
		varMap = new Alphabet (vars.length, Variable.class);
		values = new TIntArrayList (vars.length);
		setValues (vars, outcomes);
	}

	/** Sets one variable in the assignment. */
	public void setValue (Variable var, int outcome) 
	{
		int vidx = varMap.lookupIndex (var);
		if (vidx < values.size()) {
			values.set (vidx, outcome);
		} else {
			values.insert (vidx, outcome);
		}
	}

	/** Add lots of variables to the assignment. */
	public void setValues (Variable[] vars, int[] outcomes) 
	{
		for (int i = 0; i < vars.length; i++) {
			setValue (vars [i], outcomes [i]);
		}
	}

	/** Returns the value of var in this assigment. */
	public int get (Variable var) 
	{
		int idx = varMap.lookupIndex (var, false);
		if (idx == -1)
			 throw new IndexOutOfBoundsException
				 ("Assignment does not give a value for variable "+var);
		
		return values.get (varMap.lookupIndex (var, false));
	}

	public Object getObject (Variable var)
	{
		return var.lookupOutcome (get (var));
	}

	public Variable getVariable (int i)
	{
		return (Variable) varMap.lookupObject (i);
	}

	public int size()
	{
		return values.size();
	}


	public void dump ()
	{
		for (int i = 0; i < varMap.size(); i++) {
			Variable var = (Variable) varMap.lookupObject (i);
			Object obj = getObject (var);
			System.out.println(var+" "+obj);
		}
	}


	public void dumpNumeric ()
	{
		for (int i = 0; i < varMap.size(); i++) {
			Variable var = (Variable) varMap.lookupObject (i);
			int outcome = get (var);
			System.out.println(var+" "+outcome);
		}
	}

}