Module es.upm.fi.cig.multictbnc

Package es.upm.fi.cig.multictbnc.nodes

Class CPTNode

java.lang.Object

es.upm.fi.cig.multictbnc.nodes.AbstractNode

es.upm.fi.cig.multictbnc.nodes.DiscreteStateNode

es.upm.fi.cig.multictbnc.nodes.CPTNode

All Implemented Interfaces:

Node

public class CPTNode
extends DiscreteStateNode

Extends the DiscreteNode class to store a CPT and the sufficient statistics for a BN.

Constructor Summary

Constructors

Constructor	Description
CPTNode(CPTNode node)	Constructor that receives a CPTNode and clones it.
CPTNode(String name, List<String> states)	Constructor that receives the name of the variable and its possible states.
CPTNode(String name, List<String> states, boolean isClassVariable)	Constructor that receives the name of the variable, a list of strings with its possible states and if it is a class variable.

Method Summary

Modifier and Type	Method	Description
boolean	areParametersEstimated()	Returns true if the parameters of the node were estimated.
double	estimateLogLikelihood()	Returns the local log-likelihood for the node.
double	getCP(int idxStateParents, int idxStateNode)	Returns the conditional probability of a state of the node given the state of the parents.
double[][]	getCPT()	Returns the conditional probability table (CPT) of the node.
BNSufficientStatistics	getSufficientStatistics()	Returns sufficient statistics of the node.
State	sampleState(double percentageNoisyStates)	Samples the state of the node given evidence using forward sampling.
void	setCPT(double[][] CPT)	Establishes the CPT of the node.
void	setSufficientStatistics(SufficientStatistics sufficientStatistics)	Establishes the sufficient statistics of a CPT node.
String	toString()

Methods inherited from class es.upm.fi.cig.multictbnc.nodes.DiscreteStateNode

clearParentAndChildrenSets, getIdxState, getIdxStateParents, getIdxStateParents, getNumStates, getNumStatesParents, getState, getStates, removeParent, setParent, setState, setState, setStateParents

Methods inherited from class es.upm.fi.cig.multictbnc.nodes.AbstractNode

equals, getChildren, getName, getNumParents, getParents, hasChildren, hasClassVariableAsParent, hasClassVariableAsSpouse, hashCode, hasParents, isClassVariable, isClassVariable, isDisconnected, isInMarkovBlanketClassVariable, removeAllEdges, removeChild, removeChildren, removeParents, setChild

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Details

CPTNode

public CPTNode(String name,
 List<String> states)

Constructor that receives the name of the variable and its possible states.

Parameters:

name - name of the node

states - list of strings representing the states that the variable related to the node can take

CPTNode

public CPTNode(String name,
 List<String> states,
 boolean isClassVariable)

Constructor that receives the name of the variable, a list of strings with its possible states and if it is a class variable.

Parameters:

name - name of the node

states - list of strings representing the states that the variable related to the node can take

isClassVariable - true if the node represent a class variable, false otherwise

CPTNode

public CPTNode(CPTNode node)

Constructor that receives a CPTNode and clones it. Everything is cloned except the sufficient statistics.

Parameters:

node - node to clone

Method Details

getCPT

public double[][] getCPT()

Returns the conditional probability table (CPT) of the node.

Returns:

the conditional probability table of the node

setCPT

public void setCPT(double[][] CPT)

Establishes the CPT of the node.

Parameters:

CPT - CPT of the node

getCP

public double getCP(int idxStateParents,
 int idxStateNode)

Returns the conditional probability of a state of the node given the state of the parents.

Parameters:

idxStateParents - index of the parents' state

idxStateNode - index of the node state

Returns:

conditional probability of a state of the node given the state of the parent

getSufficientStatistics

public BNSufficientStatistics getSufficientStatistics()

Returns sufficient statistics of the node.

Returns:

sufficient statistics

setSufficientStatistics

public void setSufficientStatistics(SufficientStatistics sufficientStatistics)

Establishes the sufficient statistics of a CPT node.

Parameters:

sufficientStatistics - sufficient statistics of a CPT node

estimateLogLikelihood

public double estimateLogLikelihood()

Description copied from interface: Node

Returns the local log-likelihood for the node.

Returns:

local log-likelihood

sampleState

public State sampleState(double percentageNoisyStates)

Samples the state of the node given evidence using forward sampling. First it is sampled from a uniform * distribution, then it is iterated over the state of the nodes and accumulated the probability of each of them. * Once this accumulated probability is more than the sampled value from the uniform distribution, the current * state under study is returned.

Parameters:

percentageNoisyStates - value from 0 to 1 representing the probability of randomly sampling the state of the variable

Returns:

sampled state of the node. Null is returned if the state could not be sampled

areParametersEstimated

public boolean areParametersEstimated()

Description copied from interface: Node

Returns true if the parameters of the node were estimated.

Returns:

true if the parameters of the node were estimated, false otherwise

toString

public String toString()

Overrides:

toString in class DiscreteStateNode