Proposer.java 

/*
 * 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.*;
Interface for Metropolis-Hastings proposal distributions. A Proposer object must be able to create an initial state for the Markov chain, and propose a new state x' given any state x. It must also be able to compute the proposal ratio q(x | x') / q(x' | x), where q is the proposal distribution.

Implementations of the Proposer interface should have a constructor with two arguments: a blog.Model object defining the prior distribution, and a java.util.Properties object specifying configuration parameters. 


public interface Proposer {
Returns a PartialWorldDiff whose current version serves as the initial state for the Markov chain (its saved version is initially an empty instantiation). This world satisfies the given evidence and is complete enough to answer the given queries. Furthermore, the proposer stores the given evidence and queries so that proposeNextState can also maintain these properties.

Parameters: 
queries - List of Query objects


    PartialWorldDiff initialize(Evidence evidence, List queries);
Proposes a next state for the Markov chain given the current state. The world argument is a PartialWorldDiff that the proposer can modify to create the proposal; the saved version that underlies this PartialWorldDiff is the state before the proposal. Returns the log proposal ratio: log (q(x | x') / q(x' | x))

The proposed world satisfies the evidence and is complete enough to answer the queries specified in the last call to initialize. Note that if this proposal distribution is a mixture or cycle of more elementary proposal distributions, the proposal probabilities q(x | x') and q(x' | x) may be specific to the elementary distribution used for this proposal. has not been called

Throws:  IllegalStateException if initialize 


    double proposeNextState(PartialWorldDiff proposedWorld);
Prints any relevant statistics about the internal behavior of this proposer. 


    void printStats();
Updates any statistics maintained by this proposer to reflect the fact that the most recent proposal was accepted (if accepted is true) or rejected (if accepted is false). 


    void updateStats(boolean accepted);
}

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