SATIS.java

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package edu.tum.cs.srl.bayesnets.inference;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Random;

import edu.ksu.cis.bnj.ver3.core.BeliefNode;
import edu.tum.cs.bayesnets.core.BeliefNetworkEx;
import edu.tum.cs.bayesnets.inference.SATIS_BSampler;
import edu.tum.cs.bayesnets.inference.Sampler;
import edu.tum.cs.logic.GroundLiteral;
import edu.tum.cs.logic.PossibleWorld;
import edu.tum.cs.logic.WorldVariables;
import edu.tum.cs.logic.sat.ClausalKB;
import edu.tum.cs.logic.sat.Clause;
import edu.tum.cs.logic.sat.SampleSAT;
import edu.tum.cs.srl.AbstractVariable;
import edu.tum.cs.srl.bayesnets.bln.GroundBLN;
import edu.tum.cs.srl.bayesnets.bln.coupling.VariableLogicCoupling;

public class SATIS extends BNSampler {

        GroundBLN gbln;
        SampleSAT ss;
        HashSet<BeliefNode> determinedVars;
        boolean unitPropagation = false;
        
        public SATIS(GroundBLN bln) throws Exception {
                super(bln, SATIS_BSampler.class);
                gbln = bln;
                this.paramHandler.add("unitPropagation", "setUnitPropagation");

                // create SAT sampler
                PossibleWorld state = new PossibleWorld(gbln.getWorldVars());
                ss = new SampleSAT(state, gbln.getWorldVars(), gbln.getDatabase().getEntries());
                //ss = new SampleSATPriors(state, gbln.getWorldVars(), gbln.getDatabase().getEntries(), gbln.getGroundNetwork());
                paramHandler.addSubhandler(ss.getParameterHandler());
        }
        
        public void setUnitPropagation(boolean enabled) {
                unitPropagation = enabled;
        }
        
        protected void initSATSampler() throws Exception {
                System.out.println("initializing SAT sampler...");
                                
                if(unitPropagation) ss.enableUnitPropagation();
                this.ss.setDebugMode(debug);
                ClausalKB ckb = getClausalKB();
                ss.initConstraints(ckb);                
                
                // get the set of variables that is determined by the sat sampler
                determinedVars = new HashSet<BeliefNode>();
                for(Clause c : ckb) {
                        for(GroundLiteral lit : c.lits) {
                                BeliefNode var = gbln.getVariable(lit.gndAtom);
                                if(var == null)
                                        throw new Exception("Could not find node corresponding to ground atom '" + lit.gndAtom.toString() + "' with index " + lit.gndAtom.index + "; set of mapped ground atoms is " + gbln.getCoupling().getCoupledGroundAtoms());
                                determinedVars.add(var);
                        }
                }       
        }
        
        protected ClausalKB getClausalKB() throws Exception {
                return new ClausalKB(gbln.getKB());
        }
        
        @Override
        protected Sampler getSampler() throws Exception {
                initSATSampler();               
                return new SATIS_BSampler(gbln.getGroundNetwork(), ss, gbln.getCoupling(), determinedVars);
        }
        
        protected class SampleSATPriors extends SampleSAT {

                BeliefNetworkEx bn;
                HashMap<BeliefNode, double[]> priors = null;
                Random generator;
                
                public SampleSATPriors(PossibleWorld state, WorldVariables vars, Iterable<? extends AbstractVariable> db, BeliefNetworkEx bn) throws Exception {
                        super(state, vars, db);
                        this.bn = bn;
                        generator = new Random();
                }
                
                protected void setRandomState() {
                        if(priors == null)
                                priors = bn.computePriors(evidenceDomainIndices);
                        VariableLogicCoupling coupling = gbln.getCoupling();
                        for(BeliefNode node : bn.bn.getNodes()) {
                                if(!coupling.hasCoupling(node))
                                        continue;
                                int domIdx = Sampler.sample(priors.get(node), generator);
                                coupling.setVariableValue(node, domIdx, this.state);
                        }
                }
        }
}

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srldb
Author(s): Dominik Jain, Stefan Waldherr, Moritz Tenorth
autogenerated on Fri Jan 11 09:58:30 2013