/*
 * Copyright (c) 2005, Regents of the University of California
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in
 *   the documentation and/or other materials provided with the
 *   distribution.  
 *
 * * Neither the name of the University of California, Berkeley nor
 *   the names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior 
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package blog;

import java.util.*;
import java.lang.reflect.*;

import common.Util;
import common.Timer;

public class SamplingEngine extends InferenceEngine {
    

    public SamplingEngine(Model model, Properties properties) {
	super(model);

	String samplerClassName = properties.getProperty("samplerClass", 
							 "blog.LWSampler");
	System.out.println("Constructing sampler of class " 
			   + samplerClassName);

	try {
	    Class samplerClass = Class.forName(samplerClassName);
	    Class[] paramTypes = {Model.class, Properties.class};
	    Constructor constructor = samplerClass.getConstructor(paramTypes);
	    
	    Object[] args = {model, properties};
	    sampler = (Sampler) constructor.newInstance(args);
	} catch (Exception e) {
	    Util.fatalError(e);
	}

	String numSamplesStr = properties.getProperty("numSamples", "10000");
	try {
	    numSamples = Integer.parseInt(numSamplesStr);
	} catch (NumberFormatException e) {
	    Util.fatalError("Invalid number of samples: " + numSamplesStr, 
			    false);
	}

	String burnInStr = properties.getProperty("burnIn", "0");
	try {
	    numBurnIn = Integer.parseInt(burnInStr);
	} catch (NumberFormatException e) {
	    Util.fatalError("Invalid number of burn-in samples: " 
			    + burnInStr, false);
	}

	String reportIntervalStr = properties.getProperty("reportInterval", 
							  "500");
	try {
	    reportInterval = Integer.parseInt(reportIntervalStr);
	} catch (NumberFormatException e) {
	    Util.fatalError("Invalid report interval: " + reportIntervalStr, 
			    false);
	}
    }

    public void answerQueries() {
	sampler.initialize(evidence, queries);

	System.out.println("Running for " + numSamples + " samples...");
	if (numBurnIn != 0) {
	    System.out.println("(Burn-in samples: " + numBurnIn + ")");
	}
	Timer timer = new Timer();
	timer.start(); 

	for (int i = 0; i < numSamples; ++i) {
	    if (Util.verbose()) {
		System.out.println();
		System.out.println("Iteration " + i + ":");
	    }
	    sampler.nextSample(); 
	    double weight = sampler.getLatestWeight();

	    if (i >= numBurnIn) {
		if (weight > 0) {
		    // Update statistics to reflect this sample.  
		    for (Iterator iter = queries.iterator(); 
			     iter.hasNext(); ) {
			((Query) iter.next()).updateStats
			    (sampler.getLatestWorld(), weight);
		    }
		}
		
		if ((Main.outputPath() != null) 
		        && ((i+1) % Main.outputInterval() == 0)) {
		    for (Iterator iter = queries.iterator(); 
			     iter.hasNext(); ) {
			((Query) iter.next()).logResults(i+1);
		    }
		}
	    }

	    if ((i+1) % reportInterval == 0) {
		System.out.println("Samples done: " + (i+1) 
				   + ".  \tTime elapsed: " + 
				   timer.elapsedTime() + " s.");
	    }
	}

	sampler.printStats();
	//sampler.getLatestWorld().print(System.out);
    }

    private Sampler sampler;
    private int numSamples;
    private int numBurnIn;
    private int reportInterval;
}

This file was generated on Tue Jun 08 17:53:36 PDT 2010 from file SamplingEngine.java
by the ilog.language.tools.Hilite Java tool written by Hassan Aït-Kaci