weka.associations.tertius

Class Rule

java.lang.Object

weka.associations.tertius.Rule

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, RevisionHandler

public class Rule
extends java.lang.Object
implements java.io.Serializable, java.lang.Cloneable, RevisionHandler

Class representing a rule with a body and a head.

Version:

$Revision: 1.7 $

Author:

Amelie Deltour

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static java.util.Comparator	confirmationComparator Comparator used to compare two rules according to their confirmation value.
static java.util.Comparator	confirmationThenObservedComparator Comparator used to compare two rules according to their confirmation and then their observed number of counter-instances.
static java.util.Comparator	observedComparator Comparator used to compare two rules according to their observed number of counter-instances.
static java.util.Comparator	optimisticComparator Comparator used to compare two rules according to their optimistic estimate.
static java.util.Comparator	optimisticThenObservedComparator Comparator used to compare two rules according to their optimistic estimate and then their observed number of counter-instances.

Constructor Summary

Constructors

Constructor and Description
Rule(boolean repeatPredicate, int maxLiterals, boolean negBody, boolean negHead, boolean classRule, boolean horn) Constructor for a rule when the counter-instances are not stored, giving all the constraints applied to this rule.
Rule(Instances instances, boolean repeatPredicate, int maxLiterals, boolean negBody, boolean negHead, boolean classRule, boolean horn) Constructor for a rule when the counter-instances are stored, giving all the constraints applied to this rule.

Method Summary

Modifier and Type	Method and Description
boolean	bodyContains(Literal lit) Test if the body of the rule contains a literal.
void	calculateConfirmation() Calculate the confirmation of this rule.
void	calculateOptimistic() Calculate the optimistic estimate of this rule.
java.lang.Object	clone() Returns a shallow copy of this rule.
boolean	counterInstance(Instance instance) Test if an instance is a counter-instance of this rule.
boolean	equivalentTo(Rule otherRule) Test if this rule is equivalent to another rule.
double	getConfirmation() Get the confirmation value of this rule.
double	getExpectedFrequency() Get the expected frequency of counter-instances of this rule.
double	getExpectedNumber()
double	getFPRate() Get the rate of False Positive instances of this rule.
double	getObservedFrequency() Get the observed frequency of counter-instances of this rule in the dataset.
int	getObservedNumber() Get the observed number of counter-instances of this rule in the dataset.
double	getOptimistic() Get the optimistic estimate of the confirmation obtained by refining this rule.
java.lang.String	getRevision() Returns the revision string.
double	getTPRate() Get the rate of True Positive instances of this rule.
boolean	hasFalseHead() Test if the head of the rule is false.
boolean	hasTrueBody() Test if the body of the rule is true.
boolean	headContains(Literal lit) Test if the head of the rule contains a literal.
boolean	isEmpty() Test if this rule is empty.
int	numLiterals() Give the number of literals in this rule.
boolean	overFrequencyThreshold(double minFrequency) Test if this rule is over the frequency threshold.
SimpleLinkedList	refine(java.util.ArrayList predicates) Refine a rule by adding literal from a set of predictes.
java.lang.String	rocToString() Return a String giving the TP-rate and FP-rate of this rule.
boolean	sameClauseAs(Rule otherRule) Test if this rule and another rule correspond to the same clause.
boolean	subsumes(Rule otherRule) Test if this rule subsumes another rule.
java.lang.String	toString() Retrun a String for this rule.
void	upDate(Instances instances) Update the number of counter-instances of this rule in the dataset.
java.lang.String	valuesToString() Return a String giving the confirmation and optimistic estimate of this rule.

Methods inherited from class java.lang.Object

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

Field Detail

confirmationComparator

public static java.util.Comparator confirmationComparator

Comparator used to compare two rules according to their confirmation value.

observedComparator

public static java.util.Comparator observedComparator

Comparator used to compare two rules according to their observed number of counter-instances.

optimisticComparator

public static java.util.Comparator optimisticComparator

Comparator used to compare two rules according to their optimistic estimate.

confirmationThenObservedComparator

public static java.util.Comparator confirmationThenObservedComparator

Comparator used to compare two rules according to their confirmation and then their observed number of counter-instances.

optimisticThenObservedComparator

public static java.util.Comparator optimisticThenObservedComparator

Comparator used to compare two rules according to their optimistic estimate and then their observed number of counter-instances.

Constructor Detail

Rule

public Rule(boolean repeatPredicate,
            int maxLiterals,
            boolean negBody,
            boolean negHead,
            boolean classRule,
            boolean horn)

Constructor for a rule when the counter-instances are not stored, giving all the constraints applied to this rule.

Parameters:

repeatPredicate - True if predicates can be repeated.

maxLiterals - Maximum number of literals.

negBody - True if negation is allowed in the body.

negHead - True if negation is allowed in the head.

classRule - True if the rule is a classification rule.

horn - True if the rule is a horn clause.

Rule

public Rule(Instances instances,
            boolean repeatPredicate,
            int maxLiterals,
            boolean negBody,
            boolean negHead,
            boolean classRule,
            boolean horn)

Constructor for a rule when the counter-instances are stored, giving all the constraints applied to this rule. The counter-instances are initialized to all the instances in the dataset.

Parameters:

instances - The dataset.

repeatPredicate - True if predicates can be repeated.

maxLiterals - Maximum number of literals.

negBody - True if negation is allowed in the body.

negHead - True if negation is allowed in the head.

classRule - True if the rule is a classification rule.

horn - True if the rule is a horn clause.

Method Detail

clone

public java.lang.Object clone()

Returns a shallow copy of this rule. The structured is copied but the literals themselves are not copied.

Overrides:

clone in class java.lang.Object

Returns:

A copy of this Rule.

counterInstance

public boolean counterInstance(Instance instance)

Test if an instance is a counter-instance of this rule.

Parameters:

instance - The instance to test.

Returns:

True if the instance is a counter-instance.

upDate

public void upDate(Instances instances)

Update the number of counter-instances of this rule in the dataset. This method should be used is the rule does not store its counter-instances.

Parameters:

instances - The dataset.

getConfirmation

public double getConfirmation()

Get the confirmation value of this rule.

Returns:

The confirmation.

getOptimistic

public double getOptimistic()

Get the optimistic estimate of the confirmation obtained by refining this rule.

Returns:

The optimistic estimate.

getExpectedNumber

public double getExpectedNumber()

getExpectedFrequency

public double getExpectedFrequency()

Get the expected frequency of counter-instances of this rule.

Returns:

The expected frequency of counter-instances.

getObservedNumber

public int getObservedNumber()

Get the observed number of counter-instances of this rule in the dataset.

Returns:

The observed number of counter-instances.

getObservedFrequency

public double getObservedFrequency()

Get the observed frequency of counter-instances of this rule in the dataset.

Returns:

The expected frequency of counter-instances.

getTPRate

public double getTPRate()

Get the rate of True Positive instances of this rule.

Returns:

The TP-rate.

getFPRate

public double getFPRate()

Get the rate of False Positive instances of this rule.

Returns:

The FP-rate.

calculateConfirmation

public void calculateConfirmation()

Calculate the confirmation of this rule.

calculateOptimistic

public void calculateOptimistic()

Calculate the optimistic estimate of this rule.

isEmpty

public boolean isEmpty()

Test if this rule is empty.

Returns:

True if it is the empty rule.

numLiterals

public int numLiterals()

Give the number of literals in this rule.

Returns:

The number of literals.

refine

public SimpleLinkedList refine(java.util.ArrayList predicates)

Refine a rule by adding literal from a set of predictes.

Parameters:

predicates - The predicates available.

Returns:

The list of the children obtained by refining the rule.

subsumes

public boolean subsumes(Rule otherRule)

Test if this rule subsumes another rule.

Parameters:

otherRule - The other rule.

Returns:

True if the other rule is subsumed.

sameClauseAs

public boolean sameClauseAs(Rule otherRule)

Test if this rule and another rule correspond to the same clause.

Parameters:

otherRule - The other rule.

Returns:

True if both rules correspond to the same clause.

equivalentTo

public boolean equivalentTo(Rule otherRule)

Test if this rule is equivalent to another rule.

Parameters:

otherRule - The other rule.

Returns:

True if both rules are equivalent.

bodyContains

public boolean bodyContains(Literal lit)

Test if the body of the rule contains a literal.

Parameters:

lit - The literal to look for.

Returns:

True if the literal is contained in the body of the rule.

headContains

public boolean headContains(Literal lit)

Test if the head of the rule contains a literal.

Parameters:

lit - The literal to look for.

Returns:

True if the literal is contained in the head of the rule.

overFrequencyThreshold

public boolean overFrequencyThreshold(double minFrequency)

Test if this rule is over the frequency threshold.

Parameters:

minFrequency - The frequency threshold.

Returns:

True if the rule is over the threshold.

hasTrueBody

public boolean hasTrueBody()

Test if the body of the rule is true.

Returns:

True if the body is always satisfied.

hasFalseHead

public boolean hasFalseHead()

Test if the head of the rule is false.

Returns:

True if the body is never satisfied.

valuesToString

public java.lang.String valuesToString()

Return a String giving the confirmation and optimistic estimate of this rule.

Returns:

A String with the values of the rule.

rocToString

public java.lang.String rocToString()

Return a String giving the TP-rate and FP-rate of this rule.

Returns:

A String with the values of the rule.

toString

public java.lang.String toString()

Retrun a String for this rule.

Overrides:

toString in class java.lang.Object

Returns:

The String describing this rule.

getRevision

public java.lang.String getRevision()

Returns the revision string.

Specified by:

getRevision in interface RevisionHandler

Returns:

the revision