Package edu.cmu.tetrad.bayes

Class Identifiability

java.lang.Object

edu.cmu.tetrad.bayes.Identifiability

All Implemented Interfaces:

BayesUpdater, ManipulatingBayesUpdater, TetradSerializable, Serializable

public final class Identifiability
extends Object
implements ManipulatingBayesUpdater

Identifiability, based on RowSummingExactUpdater

Jin Tian and Judea Pearl. On the Identification of Causal Effects. Technical Report R-290-L, Department of Computer Science, University of California, Los Angeles, 2002.

Author:

Choh Man Teng

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
Identifiability(BayesIm bayesIm)	Constructs a new updater for the given Bayes net.
Identifiability(BayesIm bayesIm, Evidence evidence)

Method Summary

Modifier and Type	Method	Description
double[]	calculatePriorMarginals(int nodeIndex)
double[]	calculateUpdatedMarginals(int nodeIndex)
BayesIm	getBayesIm()	The BayesIm that this updater bases its update on.
Evidence	getEvidence()
double	getJointMarginal(int[] sVariables, int[] sValues)
BayesIm	getManipulatedBayesIm()
Graph	getManipulatedGraph()
double	getMarginal(int variable, int value)
BayesIm	getUpdatedBayesIm()	The updated BayesIm.
boolean	isJointMarginalSupported()
static Identifiability	serializableInstance()	Generates a simple exemplar of this class to test serialization.
void	setEvidence(Evidence evidence)	Sets new evidence for the updater.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Details

Identifiability

public Identifiability(BayesIm bayesIm)

Constructs a new updater for the given Bayes net.

Identifiability

public Identifiability(BayesIm bayesIm,
 Evidence evidence)

Method Details

serializableInstance

public static Identifiability serializableInstance()

Generates a simple exemplar of this class to test serialization.

getBayesIm

public BayesIm getBayesIm()

The BayesIm that this updater bases its update on. This BayesIm is not modified; rather, a new BayesIm is created and updated.

Specified by:

getBayesIm in interface BayesUpdater

Returns:

the Bayes instantiated model that is being updated.

getManipulatedBayesIm

public BayesIm getManipulatedBayesIm()

Specified by:

getManipulatedBayesIm in interface ManipulatingBayesUpdater

Returns:

the updated BayesIm.

getManipulatedGraph

public Graph getManipulatedGraph()

Specified by:

getManipulatedGraph in interface ManipulatingBayesUpdater

Returns:

the graph for the manipulated BayesIm.

getUpdatedBayesIm

public BayesIm getUpdatedBayesIm()

The updated BayesIm. This is a different object from the source BayesIm.

Specified by:

getUpdatedBayesIm in interface ManipulatingBayesUpdater

Returns:

the updated Bayes IM--that is, the Bayes IM in which all probabilities of variables conditional on their parents have been updated.

See Also:

• getBayesIm()

getEvidence

public Evidence getEvidence()

Specified by:

getEvidence in interface ManipulatingBayesUpdater

Returns:

a defensive copy of the evidence.

setEvidence

public void setEvidence(Evidence evidence)

Description copied from interface: ManipulatingBayesUpdater

Sets new evidence for the updater. Once this is called, old updating results should not longer be available.

Specified by:

setEvidence in interface BayesUpdater

Specified by:

setEvidence in interface ManipulatingBayesUpdater

isJointMarginalSupported

public boolean isJointMarginalSupported()

Specified by:

isJointMarginalSupported in interface BayesUpdater

Returns:

true if the getJointMarginal() method is supported.

getJointMarginal

public double getJointMarginal(int[] sVariables,
 int[] sValues)

Specified by:

getJointMarginal in interface BayesUpdater

Returns:

P(variables[i] = values[i] | evidence), where evidence is getEvidence().

getMarginal

public double getMarginal(int variable,
 int value)

Specified by:

getMarginal in interface BayesUpdater

Specified by:

getMarginal in interface ManipulatingBayesUpdater

Returns:

P(variable = category | evidence) where evidence is getEvidence().

calculatePriorMarginals

public double[] calculatePriorMarginals(int nodeIndex)

Specified by:

calculatePriorMarginals in interface BayesUpdater

calculateUpdatedMarginals

public double[] calculateUpdatedMarginals(int nodeIndex)

Specified by:

calculateUpdatedMarginals in interface BayesUpdater

toString

public String toString()

Overrides:

toString in class Object