Package edu.cmu.tetrad.bayes

Class BayesImProbs

java.lang.Object

edu.cmu.tetrad.bayes.BayesImProbs

All Implemented Interfaces:

TetradSerializable, Serializable

public final class BayesImProbs
extends Object
implements TetradSerializable

Calculates cell probabilities from conditional BayesIm probabilities on the fly without constructing the entire table. (To force the entire table to be constructed, use StoredCellProbs.)

Version:

$Id: $Id

Author:

josephramsey

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
BayesImProbs(BayesIm bayesIm)	Constructs a BayesImProbs object from the given BayesIm.

Method Summary

Modifier and Type	Method	Description
double	getCellProb(int[] variableValues)	Calculates the probability in the given cell from the conditional probabilities in the BayesIm.
double	getConditionalProb(Proposition assertion, Proposition condition)	Calculates the conditional probability of an assertion given a condition.
double	getProb(Proposition assertion)	Calculates the probability of a given proposition.
List<Node>	getVariables()	Getter for the field variables.
static BayesImProbs	serializableInstance()	Generates a simple exemplar of this class to test serialization.

Methods inherited from class java.lang.Object

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

Constructor Details

BayesImProbs

public BayesImProbs(BayesIm bayesIm)

Constructs a BayesImProbs object from the given BayesIm.

Parameters:

bayesIm - Ibid.

Method Details

serializableInstance

public static BayesImProbs serializableInstance()

Generates a simple exemplar of this class to test serialization.

Returns:

a simple exemplar of this class to test serialization.

getCellProb

public double getCellProb(int[] variableValues)

Calculates the probability in the given cell from the conditional probabilities in the BayesIm. It's the product of the probabilities that each variable takes on the value it does given that the other variables take on the values they do in that cell. The returned value will be undefined (Double.NaN) if any of the conditional probabilities being multiplied together is undefined.

Parameters:

variableValues - the values of the variables in the cell

Returns:

the cell probability, or NaN if this probability is undefined.

getProb

public double getProb(Proposition assertion)

Calculates the probability of a given proposition.

Parameters:

assertion - the proposition for which we want to calculate the probability

Returns:

the probability of the given proposition

getConditionalProb

public double getConditionalProb(Proposition assertion,
 Proposition condition)

Calculates the conditional probability of an assertion given a condition.

Parameters:

assertion - the proposition representing the assertion

condition - the proposition representing the condition

Returns:

the conditional probability of the assertion given the condition

Throws:

IllegalArgumentException - if the assertion and condition are not for the same Bayes IM

getVariables

public List<Node> getVariables()

Getter for the field variables.

Returns:

a List object