cc.mallet.grmm.inference
Class BruteForceInferencer

java.lang.Object
  cc.mallet.grmm.inference.AbstractInferencer
      cc.mallet.grmm.inference.BruteForceInferencer

All Implemented Interfaces:

Inferencer, java.io.Serializable, java.lang.Cloneable

public class BruteForceInferencer
extends AbstractInferencer
implements Inferencer

Computes the joint of a GraphicalModel by brute-force calculation. This is exponentially slow, so it is mostly useful as a sanity check on more complicated algorithms. Created: Wed Sep 17 13:21:13 2003

Version:

$Id: BruteForceInferencer.java,v 1.1 2007/10/22 21:37:49 mccallum Exp $

Author:

Charles Sutton

See Also:

Serialized Form

Constructor Summary

BruteForceInferencer()

Method Summary

void	computeMarginals(FactorGraph mdl) Computes marginal distributions for a factor graph.
void	computeMarginals(JunctionTree jt)
Factor	joint(FactorGraph model)
Factor	joint(JunctionTree jt)
double	lookupJoint(Assignment assn) Returns the joint probability of a given assignment, computed in some factorized fashion.
double	lookupLogJoint(Assignment assn) Returns the natural logarithm of the joint probability of a given assignment, computed in some factorized fashion.
Factor	lookupMarginal(Variable var) Returns the computed marginal of a given variable.
Factor	lookupMarginal(VarSet c) Returns the computed marginal of a given clique in a graph.

Methods inherited from class cc.mallet.grmm.inference.AbstractInferencer

dump, duplicate, query, reportTime

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface cc.mallet.grmm.inference.Inferencer

dump, duplicate, query, reportTime

Constructor Detail

BruteForceInferencer

public BruteForceInferencer()

Method Detail

joint

public Factor joint(FactorGraph model)

joint

public Factor joint(JunctionTree jt)

computeMarginals

public void computeMarginals(FactorGraph mdl)

Description copied from interface: Inferencer

Computes marginal distributions for a factor graph.

Specified by:

computeMarginals in interface Inferencer

Specified by:

computeMarginals in class AbstractInferencer

computeMarginals

public void computeMarginals(JunctionTree jt)

lookupMarginal

public Factor lookupMarginal(Variable var)

Description copied from interface: Inferencer

Returns the computed marginal of a given variable. Before using this method, computeMarginals must have been previously called on the graphical model that contains v.

Specified by:

lookupMarginal in interface Inferencer

Specified by:

lookupMarginal in class AbstractInferencer

See Also:

Inferencer.computeMarginals(FactorGraph)

lookupMarginal

public Factor lookupMarginal(VarSet c)

Description copied from interface: Inferencer

Returns the computed marginal of a given clique in a graph. Before using this method, computeMarginals must have been previously called on the graphical model that contains the clique.

Specified by:

lookupMarginal in interface Inferencer

Overrides:

lookupMarginal in class AbstractInferencer

See Also:

Inferencer.computeMarginals(cc.mallet.grmm.types.FactorGraph), #computeMarginals(JunctionTree)

lookupJoint

public double lookupJoint(Assignment assn)

Description copied from interface: Inferencer

Returns the joint probability of a given assignment, computed in some factorized fashion. Before using this method, computeMarginals must have been previously called on the graphical model that contains the variables of assn.

Specified by:

lookupJoint in interface Inferencer

Overrides:

lookupJoint in class AbstractInferencer

See Also:

Inferencer.computeMarginals(cc.mallet.grmm.types.FactorGraph), #computeMarginals(JunctionTree)

lookupLogJoint

public double lookupLogJoint(Assignment assn)

Description copied from interface: Inferencer

Returns the natural logarithm of the joint probability of a given assignment, computed in some factorized fashion. Before using this method, computeMarginals must have been previously called on the graphical model that contains the variables of assn.

This method is less likely to underflow than Math.log (lookupJoint (assn)).

Specified by:

lookupLogJoint in interface Inferencer

Overrides:

lookupLogJoint in class AbstractInferencer

See Also:

Inferencer.computeMarginals(cc.mallet.grmm.types.FactorGraph), #computeMarginals(JunctionTree)