org.coode.oppl.similarity

Class SymbolBasedSimilarity

java.lang.Object

org.coode.oppl.similarity.SymbolBasedSimilarity

All Implemented Interfaces:

SimilarityMeasure<org.semanticweb.owlapi.model.OWLObject>

public class SymbolBasedSimilarity
extends Object
implements SimilarityMeasure<org.semanticweb.owlapi.model.OWLObject>

Compares OWLObject instances only based on the symbols they contain.

Author:

Luigi Iannone

Constructor Summary

Constructors

Constructor and Description
SymbolBasedSimilarity()

Method Summary

Modifier and Type	Method and Description
double	compare(org.semanticweb.owlapi.model.OWLObject anObject, org.semanticweb.owlapi.model.OWLObject anotherObject) Compares the two input objects.
protected double	compareSymbols(Collection<? extends org.semanticweb.owlapi.model.OWLObject> anObjectSymbols, Collection<? extends org.semanticweb.owlapi.model.OWLObject> anotherObjectSymbols) Compares symbols computing the ratio of the size of their intersection over the size of their union.
protected Set<org.semanticweb.owlapi.model.OWLObject>	extractSymbols(org.semanticweb.owlapi.model.OWLObject anObject) Extracts the relevant symbols for the comparison.
boolean	isSymmetric()

Methods inherited from class java.lang.Object

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

Constructor Detail

SymbolBasedSimilarity

public SymbolBasedSimilarity()

Method Detail

compare

public double compare(org.semanticweb.owlapi.model.OWLObject anObject,
                      org.semanticweb.owlapi.model.OWLObject anotherObject)

Description copied from interface: SimilarityMeasure

Compares the two input objects. It required for this interface to implement this method in accordance to the equals method available for O. If isSymmetric returns true, then it must hold that compare(A,B) == compare (B,A).

Specified by:

compare in interface SimilarityMeasure<org.semanticweb.owlapi.model.OWLObject>

Parameters:

anObject - the first object to compare. cannot be null.

anotherObject - the first object to compare. cannot be null.

Returns:

a number between 0 and 1. 1 corresponds to maximum similarity, 0 to minimal

compareSymbols

protected double compareSymbols(Collection<? extends org.semanticweb.owlapi.model.OWLObject> anObjectSymbols,
                                Collection<? extends org.semanticweb.owlapi.model.OWLObject> anotherObjectSymbols)

Compares symbols computing the ratio of the size of their intersection over the size of their union. Users may override this for different comparison strategies.

Parameters:

anObjectSymbols - First Collection of Symbols. Cannot be null.

anotherObjectSymbols - Second Collection of Symbols. Cannot be null.

Returns:

the double representing the result of the comparison.

Throws:

NullPointerException - when either input is null.

extractSymbols

protected Set<org.semanticweb.owlapi.model.OWLObject> extractSymbols(org.semanticweb.owlapi.model.OWLObject anObject)

Extracts the relevant symbols for the comparison. Override this when a different set of symbols from the all the OWLEntity and OWLConstant appearing the input object should be used.

Parameters:

anObject - The OWLObject from which the symbols should be extracted. Cannot be null.

Returns:

a Set containing the OWL Object (symbols) that can be used for the comparison. 1 corresponds to maximum similarity, 0 to minimal.

Throws:

NullPointerException - when the input is null.

isSymmetric

public boolean isSymmetric()

Specified by:

isSymmetric in interface SimilarityMeasure<org.semanticweb.owlapi.model.OWLObject>

Returns:

true if compare(A,B) == compare (B,A)