aima.core.probability.bayes.impl

Class CPT

java.lang.Object

aima.core.probability.bayes.impl.CPT

All Implemented Interfaces:

ConditionalProbabilityDistribution, ConditionalProbabilityTable

public class CPT
extends java.lang.Object
implements ConditionalProbabilityTable

Default implementation of the ConditionalProbabilityTable interface.

Author:

Ciaran O'Reilly

Constructor Summary

Constructors

Constructor and Description
CPT(RandomVariable on, double[] values, RandomVariable... conditionedOn)

Method Summary

Modifier and Type	Method and Description
boolean	contains(RandomVariable rv)
CategoricalDistribution	getConditioningCase(AssignmentProposition... parentValues) A conditioning case is just a possible combination of values for the parent nodes - a miniature possible world, if you like.
CategoricalDistribution	getConditioningCase(java.lang.Object... parentValues) A conditioning case is just a possible combination of values for the parent nodes - a miniature possible world, if you like.
Factor	getFactorFor(AssignmentProposition... evidence) Construct a Factor consisting of the Random Variables from the Conditional Probability Table that are not part of the evidence (see AIMA3e pg.
java.util.Set<RandomVariable>	getFor() A convenience method for merging the elements of getParents() and getOn() into a consistent ordered set (i.e.
RandomVariable	getOn()
java.util.Set<RandomVariable>	getParents()
java.lang.Object	getSample(double probabilityChoice, AssignmentProposition... parentValues) Retrieve a specific example for the Random Variable this conditional distribution is on.
java.lang.Object	getSample(double probabilityChoice, java.lang.Object... parentValues) Retrieve a specific example for the Random Variable this conditional distribution is on.
double	getValue(AssignmentProposition... eventValues) Get the value for the provided set of AssignmentPropositions for the random variables comprising the Conditional Distribution (size of each must equal and their random variables must match).
double	getValue(java.lang.Object... eventValues) Get the value for the provided set of values for the random variables comprising the Conditional Distribution (ordering and size of each must equal getFor() and their domains must match).
double	probabilityFor(java.lang.Object... values)

Methods inherited from class java.lang.Object

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

Constructor Detail

CPT

public CPT(RandomVariable on,
           double[] values,
           RandomVariable... conditionedOn)

Method Detail

probabilityFor

public double probabilityFor(java.lang.Object... values)

getOn

public RandomVariable getOn()

Specified by:

getOn in interface ConditionalProbabilityDistribution

Returns:

the Random Variable this conditional probability distribution is on.

getParents

public java.util.Set<RandomVariable> getParents()

Specified by:

getParents in interface ConditionalProbabilityDistribution

Returns:

a consistent ordered Set (e.g. LinkedHashSet) of the parent Random Variables for this conditional distribution.

getFor

public java.util.Set<RandomVariable> getFor()

Description copied from interface: ConditionalProbabilityDistribution

A convenience method for merging the elements of getParents() and getOn() into a consistent ordered set (i.e. getOn() should always be the last Random Variable returned when iterating over the set).

Specified by:

getFor in interface ConditionalProbabilityDistribution

Returns:

a consistent ordered Set (e.g. LinkedHashSet) of the random variables this conditional probability distribution is for.

contains

public boolean contains(RandomVariable rv)

Specified by:

contains in interface ConditionalProbabilityDistribution

Parameters:

rv - the Random Variable to be checked.

Returns:

true if the conditional distribution is for the passed in Random Variable, false otherwise.

getValue

public double getValue(java.lang.Object... eventValues)

Description copied from interface: ConditionalProbabilityDistribution

Get the value for the provided set of values for the random variables comprising the Conditional Distribution (ordering and size of each must equal getFor() and their domains must match).

Specified by:

getValue in interface ConditionalProbabilityDistribution

Parameters:

eventValues - the values for the random variables comprising the Conditional Distribution

Returns:

the value for the possible worlds associated with the assignments for the random variables comprising the Conditional Distribution.

getValue

public double getValue(AssignmentProposition... eventValues)

Description copied from interface: ConditionalProbabilityDistribution

Get the value for the provided set of AssignmentPropositions for the random variables comprising the Conditional Distribution (size of each must equal and their random variables must match).

Specified by:

getValue in interface ConditionalProbabilityDistribution

Parameters:

eventValues - the assignment propositions for the random variables comprising the Conditional Distribution

Returns:

the value for the possible worlds associated with the assignments for the random variables comprising the Conditional Distribution.

getSample

public java.lang.Object getSample(double probabilityChoice,
                                  java.lang.Object... parentValues)

Description copied from interface: ConditionalProbabilityDistribution

Retrieve a specific example for the Random Variable this conditional distribution is on.

Specified by:

getSample in interface ConditionalProbabilityDistribution

Parameters:

probabilityChoice - a double value, from the range [0.0d, 1.0d), i.e. 0.0d (inclusive) to 1.0d (exclusive).

parentValues - for the conditioning case. The ordering and size of parentValues must equal getParents() and their domains must match.

Returns:

a sample value from the domain of the Random Variable this distribution is on, based on the probability argument passed in.

See Also:

ConditionalProbabilityDistribution.getOn()

getSample

public java.lang.Object getSample(double probabilityChoice,
                                  AssignmentProposition... parentValues)

Description copied from interface: ConditionalProbabilityDistribution

Retrieve a specific example for the Random Variable this conditional distribution is on.

Specified by:

getSample in interface ConditionalProbabilityDistribution

Parameters:

probabilityChoice - a double value, from the range [0.0d, 1.0d), i.e. 0.0d (inclusive) to 1.0d (exclusive).

parentValues - for the conditioning case. The size of parentValues must equal getParents() and their Random Variables must match.

Returns:

a sample value from the domain of the Random Variable this distribution is on, based on the probability argument passed in.

See Also:

ConditionalProbabilityDistribution.getOn()

getConditioningCase

public CategoricalDistribution getConditioningCase(java.lang.Object... parentValues)

Description copied from interface: ConditionalProbabilityDistribution

A conditioning case is just a possible combination of values for the parent nodes - a miniature possible world, if you like. The returned distribution must sum to 1, because the entries represent an exhaustive set of cases for the random variable.

Specified by:

getConditioningCase in interface ConditionalProbabilityDistribution

Specified by:

getConditioningCase in interface ConditionalProbabilityTable

Parameters:

parentValues - for the conditioning case. The ordering and size of parentValues must equal getParents() and their domains must match.

Returns:

the Probability Distribution for the Random Variable the Conditional Probability Distribution is On.

See Also:

ConditionalProbabilityDistribution.getOn(), ConditionalProbabilityDistribution.getParents()

getConditioningCase

public CategoricalDistribution getConditioningCase(AssignmentProposition... parentValues)

Description copied from interface: ConditionalProbabilityDistribution

A conditioning case is just a possible combination of values for the parent nodes - a miniature possible world, if you like. The returned distribution must sum to 1, because the entries represent an exhaustive set of cases for the random variable.

Specified by:

getConditioningCase in interface ConditionalProbabilityDistribution

Specified by:

getConditioningCase in interface ConditionalProbabilityTable

Parameters:

parentValues - for the conditioning case. The size of parentValues must equal getParents() and their Random Variables must match.

Returns:

the Probability Distribution for the Random Variable the Conditional Probability Distribution is On.

See Also:

ConditionalProbabilityDistribution.getOn(), ConditionalProbabilityDistribution.getParents()

getFactorFor

public Factor getFactorFor(AssignmentProposition... evidence)

Description copied from interface: ConditionalProbabilityTable

Construct a Factor consisting of the Random Variables from the Conditional Probability Table that are not part of the evidence (see AIMA3e pg. 524).

Specified by:

getFactorFor in interface ConditionalProbabilityTable

Returns:

a Factor for the Random Variables from the Conditional Probability Table that are not part of the evidence.