edu.oregonstate.eecs.mcplan.search.fsss.FsssTreeBuilder.java Source code

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Here is the source code for edu.oregonstate.eecs.mcplan.search.fsss.FsssTreeBuilder.java

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/* LICENSE
Copyright (c) 2013-2016, Jesse Hostetler (jessehostetler@gmail.com)
All rights reserved.
    
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
    
1. Redistributions of source code must retain the above copyright notice,
   this list of conditions and the following disclaimer.
2. 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.
    
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 edu.oregonstate.eecs.mcplan.search.fsss;

import org.apache.commons.math3.random.MersenneTwister;
import org.apache.commons.math3.random.RandomGenerator;

import edu.oregonstate.eecs.mcplan.State;
import edu.oregonstate.eecs.mcplan.VirtualConstructor;
import edu.oregonstate.eecs.mcplan.domains.cards.InfiniteSpanishDeck;
import edu.oregonstate.eecs.mcplan.domains.spbj.SpBjAction;
import edu.oregonstate.eecs.mcplan.domains.spbj.SpBjFsssModel;
import edu.oregonstate.eecs.mcplan.domains.spbj.SpBjState;

/**
 * @author jhostetler
 *
 */
public class FsssTreeBuilder<S extends State, A extends VirtualConstructor<A>> {
    private final FsssModel<S, A> m;
    private final int width;
    private final int depth;

    public FsssTreeBuilder(final FsssModel<S, A> m, final int width, final int depth) {
        this.m = m;
        this.width = width;
        this.depth = depth;
    }

    public FsssStateNode<S, A> buildTree(final S s) {
        final FsssStateNode<S, A> root = new FsssStateNode<S, A>(depth, m, s);
        int iter = 0;
        while (true) {
            if (iter++ % 100 == 0) {
                System.out.println("Iteration " + iter);
            }

            fsss(root, depth);

            // Stop search if L(root, a*) >= U(root, a) forall a != a*
            final FsssActionNode<S, A> astar = root.astar();
            final double Lstar = astar.L();
            boolean done = true;
            for (final FsssActionNode<S, A> alt : root.successors()) {
                if (alt != astar && alt.U() > Lstar) {
                    done = false;
                    break;
                }
            }
            if (done) {
                break;
            }
        }
        return root;
    }

    private void fsss(final FsssStateNode<S, A> sn, final int d) {
        if (!sn.isTerminal()) {
            if (sn.nvisits() == 0) {
                //            System.out.println( "Expanding " + sn.s() + " at depth " + d );
                sn.expand(m.actions(sn.s()), width);
            }
            sn.visit();
            final FsssActionNode<S, A> astar = sn.astar();
            final FsssStateNode<S, A> sstar = astar.sstar();
            fsss(sstar, d - 1);
            astar.backup();
            sn.backup();
        } else {
            //         System.out.println( "\tLeaf " + sn.s() + " at depth " + d );
            //         sn.leaf( m.actions( sn.s() ) );
            sn.leaf();
        }
        //      sn.backup();
    }

    // -----------------------------------------------------------------------

    public static void main(final String[] argv) {
        final int width = 20;
        final int depth = 4;

        final RandomGenerator rng = new MersenneTwister(76925342);
        final SpBjFsssModel model = new SpBjFsssModel(rng);
        final InfiniteSpanishDeck deck = new InfiniteSpanishDeck(rng);
        final SpBjState s0 = new SpBjState(deck);
        s0.init();
        final FsssTreeBuilder<SpBjState, SpBjAction> tb = new FsssTreeBuilder<SpBjState, SpBjAction>(model, width,
                depth);

        final long then = System.currentTimeMillis();
        final FsssStateNode<SpBjState, SpBjAction> root = tb.buildTree(s0);
        final long now = System.currentTimeMillis();

        FsssTest.printTree(root, System.out, 1);

        System.out.println("Elapsed time: " + (now - then) + " ms");

        //      final InventoryProblem problem = InventoryProblem.TwoProducts();
        //      final InventoryFsssModel model = new InventoryFsssModel( problem );
        //      final InventoryFsssAbstractionTrivial abstraction = new InventoryFsssAbstractionTrivial( problem, model );
        //      final RandomGenerator rng = new MersenneTwister( 45 );
        //      final InventoryState s0 = new InventoryState( rng, problem );
        //      final FsssParTreeBuilder<InventoryState, InventoryAction> tb
        //         = new FsssParTreeBuilder<InventoryState, InventoryAction>( model, abstraction, width, depth, s0 );
        //      tb.buildTree();
    }
}