gov.sandia.cognition.graph.inference

Class EdgeMergingEnergyFunction<LabelType,NodeNameType>

java.lang.Object

gov.sandia.cognition.graph.inference.EdgeMergingEnergyFunction<LabelType,NodeNameType>

Type Parameters:

LabelType -

NodeNameType -

All Implemented Interfaces:

EnergyFunction<LabelType>, NodeNameAwareEnergyFunction<LabelType,NodeNameType>

public class EdgeMergingEnergyFunction<LabelType,NodeNameType>
extends java.lang.Object
implements NodeNameAwareEnergyFunction<LabelType,NodeNameType>

Our implementation of belief propagation requires that there be at most one edge between any pair of nodes. This class wraps any graph (with any number of edges between pairs of nodes) and merges any edges between any two nodes into one BP-visible edge while preserving the correct results. This wrapper makes the edges undirected (changing the direction stored in this class from that stored in the parent class), so don't use with SumProductPairwiseBayesNet.

Author:

jdwendt

Constructor Summary

Constructors

Constructor and Description
EdgeMergingEnergyFunction(NodeNameAwareEnergyFunction<LabelType,NodeNameType> wrapMe) Initializes this edge merging energy function

Method Summary

Modifier and Type	Method and Description
java.util.Map<LabelType,java.lang.Double>	getBeliefs(NodeNameType node, EnergyFunctionSolver<LabelType> bp) Get the probabilities for each label for the input node as produced by the input belief propagation run.
Pair<java.lang.Integer,java.lang.Integer>	getEdge(int i) Returns the indices for the two endpoints in the specified path.
double	getPairwiseCost(int edgeId, LabelType ilabel, LabelType jlabel) This is the -log(getPairwisePotential(.)).
double	getPairwisePotential(int edgeId, LabelType ilabel, LabelType jlabel) Returns the pairwise cost of node i being assigned label_i and node j being assigned label_j.
java.util.Collection<LabelType>	getPossibleLabels(int nodeId) Returns the set of labels that this message passer supports
double	getUnaryCost(int i, LabelType label) This is the -log(getUnaryPotential(.)).
double	getUnaryPotential(int i, LabelType label) Returns the unary cost for node i having the input label.
int	numEdges() Returns the number of paths that messages should be passed down.
int	numNodes() Returns the number of nodes in the energy function.
void	setLabel(NodeNameType node, LabelType label) Set the label for the input node

Methods inherited from class java.lang.Object

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

Constructor Detail

EdgeMergingEnergyFunction

public EdgeMergingEnergyFunction(NodeNameAwareEnergyFunction<LabelType,NodeNameType> wrapMe)

Initializes this edge merging energy function

Parameters:

wrapMe - The energy function to wrap

Method Detail

setLabel

public void setLabel(NodeNameType node,
                     LabelType label)

Description copied from interface: NodeNameAwareEnergyFunction

Set the label for the input node

Specified by:

setLabel in interface NodeNameAwareEnergyFunction<LabelType,NodeNameType>

See Also:

NodeNameAwareEnergyFunction.setLabel(java.lang.Object, java.lang.Object)

getBeliefs

public java.util.Map<LabelType,java.lang.Double> getBeliefs(NodeNameType node,
                                                            EnergyFunctionSolver<LabelType> bp)

Description copied from interface: NodeNameAwareEnergyFunction

Get the probabilities for each label for the input node as produced by the input belief propagation run.

Specified by:

getBeliefs in interface NodeNameAwareEnergyFunction<LabelType,NodeNameType>

Returns:

See Also:

NodeNameAwareEnergyFunction.getBeliefs(java.lang.Object, gov.sandia.cognition.graph.inference.EnergyFunctionSolver)

getPossibleLabels

public java.util.Collection<LabelType> getPossibleLabels(int nodeId)

Description copied from interface: EnergyFunction

Returns the set of labels that this message passer supports

Specified by:

getPossibleLabels in interface EnergyFunction<LabelType>

Parameters:

nodeId - The node whose labels is wanted

Returns:

the set of labels that this message passer supports

See Also:

EnergyFunction.getPossibleLabels(int)

numEdges

public int numEdges()

Description copied from interface: EnergyFunction

Returns the number of paths that messages should be passed down. In conjunction with the EnergyFunction.getEdge(int) method, all paths can be retrieved.

Specified by:

numEdges in interface EnergyFunction<LabelType>

Returns:

the number of paths that messages can be passed through

See Also:

EnergyFunction.numEdges()

numNodes

public int numNodes()

Description copied from interface: EnergyFunction

Returns the number of nodes in the energy function.

Specified by:

numNodes in interface EnergyFunction<LabelType>

Returns:

the number of nodes in the energy function

See Also:

EnergyFunction.numNodes()

getEdge

public Pair<java.lang.Integer,java.lang.Integer> getEdge(int i)

Description copied from interface: EnergyFunction

Returns the indices for the two endpoints in the specified path. The path ID should be 0-indexed and all paths from 0 through ( EnergyFunction.numEdges() - 1) should return a non-null value. All path IDs outside that range should throw an Exception.

Specified by:

getEdge in interface EnergyFunction<LabelType>

Parameters:

i - The path ID (should be in [0 ... EnergyFunction.numEdges()) ).

Returns:

The two endpoints' IDs (to be used for #getUnaryCost(int) and #getPairwisePotential(int, int, Object, Object))

See Also:

EnergyFunction.getEdge(int)

getUnaryPotential

public double getUnaryPotential(int i,
                                LabelType label)

Description copied from interface: EnergyFunction

Returns the unary cost for node i having the input label. i must be a valid node id returned from EnergyFunction.getEdge(int). If not, an exception should be thrown.

Specified by:

getUnaryPotential in interface EnergyFunction<LabelType>

Parameters:

i - The index of the node whose unary cost should be returned

label - The label that could be applied to the node

Returns:

The unary cost of node i being assigned the input label

See Also:

EnergyFunction.getUnaryPotential(int, java.lang.Object)

getPairwisePotential

public double getPairwisePotential(int edgeId,
                                   LabelType ilabel,
                                   LabelType jlabel)

Description copied from interface: EnergyFunction

Returns the pairwise cost of node i being assigned label_i and node j being assigned label_j. NOTE: i and j must be the two endpoints returned by EnergyFunction.getEdge(int) in the ordere specified by the returned pair (i = getFirst, j = getSecond). If not, an exception should be thrown.

Specified by:

getPairwisePotential in interface EnergyFunction<LabelType>

Parameters:

edgeId - The id for the edge being requested

ilabel - The label being (possibly) assigned to node i

jlabel - The label being (possibly) assigned to node j

Returns:

the pairwise cost of node i being assigned label_i and node j being assigned label_j

See Also:

EnergyFunction.getPairwisePotential(int, java.lang.Object, java.lang.Object)

getUnaryCost

public double getUnaryCost(int i,
                           LabelType label)

Description copied from interface: EnergyFunction

This is the -log(getUnaryPotential(.)).

Specified by:

getUnaryCost in interface EnergyFunction<LabelType>

Returns:

See Also:

EnergyFunction.getUnaryCost(int, java.lang.Object)

getPairwiseCost

public double getPairwiseCost(int edgeId,
                              LabelType ilabel,
                              LabelType jlabel)

Description copied from interface: EnergyFunction

This is the -log(getPairwisePotential(.)).

Specified by:

getPairwiseCost in interface EnergyFunction<LabelType>

Returns:

See Also:

EnergyFunction.getPairwiseCost(int, java.lang.Object, java.lang.Object)