Query.html

Query.java

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package blog;

import java.util.*;
import java.io.PrintStream;
import ve.Factor;

Interface for queries that can be answered by an inference engine. A Query object records both results from a single run of an inference algorithm, and statistics about the results of several runs (if the inference algorithm is randomized, each run may yield different results).

The getVariables method returns a set of random variables such that the result of this query depends only on the posterior joint distribution of these variables. There are two ways in which this posterior distribution can be provided to the Query object. One is to call updateStats repeatedly, passing in partial worlds with weights; these worlds must be complete enough to define values for all the query's variables. The other way is to pass in a factor over these variables using setPosterior.


public interface Query {

Prints the results of this query to the given stream.


    void printResults(PrintStream s);

If a log file has been specified, prints the results so far to that file. engine so far (can be set to zero for non-sampling inference engines)

Parameters:

numSamples - the number of samples taken by the inference


    void logResults(int numSamples);

Returns a collection of (basic or derived) random variables such that the result of this query depends only on the posterior joint distribution for these variables. yet been called

Throws: IllegalStateException if compile has not


    Collection<? extends BayesNetVar> getVariables();

Returns true if this query satisfies type and scope constraints. If there is a type or scope error, prints a message to standard error and returns false.


    public boolean checkTypesAndScope(Model model);

Does compilation steps that can only be done correctly once the model is complete. Prints messages to standard error if any errors are encountered. Returns the number of errors encountered.


    public int compile();

Updates the within-run statistics for this query to reflect the given world sampled with the given weight. The world must be complete enough to define values for all the variables returned by getVariables.

The effects of calling both updateStats and setPosterior in the same run are not defined.


    void updateStats(PartialWorld world, double weight);

Sets the posterior distribution for the variables returned by getVariables. This overwrites any results specified previously for the current run using this method or updateStats.

The effects of calling both updateStats and setPosterior in the same run are not defined. as the collection returned by getVariables, and whose entries sum to 1

Parameters:

posterior - factor whose set of variables is the same


    void setPosterior(Factor posterior);

Ends the current run, records across-run statistics for it, and clears the within-run statistics.


    void zeroOut();

Prints across-run statistics.


    void printVarianceResults(PrintStream s);

Returns an object whose toString method yields a description of the location where this query occurred in an input file.


    public abstract Object getLocation();
}

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