MixtureDistrib.java 

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package blog.distrib;

import blog.*;
import java.util.*;
import common.Util;
A mixture of conditional probability distributions. The distributions being mixed together can have arguments, but the mixing probabilities cannot depend on the arguments. Currently this class does not have the standard constructor taking a list of parameters. 


public class MixtureDistrib extends AbstractCondProbDistrib {
Creates a new MixtureDistrib that combines the given distributions according to the given probabilities. The arrays of distributions and probabilities must have the same length. 


    public MixtureDistrib(CondProbDistrib[] distribs, double[] probs) {
	this.distribs = (CondProbDistrib[]) distribs.clone();
	this.mixDistrib = new Categorical(probs);
    }

    public double getProb(List args, Object value) {
	double prob = 0;
	for (int i = 0; i < distribs.length; ++i) {
	    prob += (mixDistrib.getProb(i) * distribs[i].getProb(args, value));
	}
	return prob;
    }

    public double getLogProb(List args, Object value) {
	double logProb = Double.NEGATIVE_INFINITY;
	for (int i = 0; i < distribs.length; ++i) {
	    logProb = Util.logSum(logProb, 
				  (mixDistrib.getLogProb(i) 
				   + distribs[i].getLogProb(args, value)));
	}
	return logProb;
    }

    public Object sampleVal(List args, Type childType) {
	int index = mixDistrib.sampleVal();
	return distribs[index].sampleVal(args, childType);
    }

    private CondProbDistrib[] distribs;
    private Categorical mixDistrib;
}

This file was generated on Tue Jun 08 17:53:47 PDT 2010 from file MixtureDistrib.java
by the ilog.language.tools.Hilite Java tool written by Hassan Aït-Kaci