[DL-Learner SVN] SF.net SVN: dl-learner:[2005] trunk/src/dl-learner/org/dllearner

[<jen...@us...>]

Revision: 2005
          http://dl-learner.svn.sourceforge.net/dl-learner/?rev=2005&view=rev
Author:   jenslehmann
Date:     2010-02-10 12:19:56 +0000 (Wed, 10 Feb 2010)

Log Message:
-----------
- implemented CELOE option to reuse an existing definition for learning a new one
  (involves using upward refinement to detect an appropriate start class)

Modified Paths:
--------------
    trunk/src/dl-learner/org/dllearner/algorithms/celoe/CELOE.java
    trunk/src/dl-learner/org/dllearner/core/ReasonerComponent.java
    trunk/src/dl-learner/org/dllearner/core/SchemaReasoner.java
    trunk/src/dl-learner/org/dllearner/reasoning/OWLAPIReasoner.java

Modified: trunk/src/dl-learner/org/dllearner/algorithms/celoe/CELOE.java
===================================================================
--- trunk/src/dl-learner/org/dllearner/algorithms/celoe/CELOE.java	2010-02-10 11:57:19 UTC (rev 2004)
+++ trunk/src/dl-learner/org/dllearner/algorithms/celoe/CELOE.java	2010-02-10 12:19:56 UTC (rev 2005)
@@ -50,6 +50,7 @@
 import org.dllearner.learningproblems.PosNegLP;
 import org.dllearner.learningproblems.PosNegLPStandard;
 import org.dllearner.learningproblems.PosOnlyLP;
+import org.dllearner.refinementoperators.OperatorInverter;
 import org.dllearner.refinementoperators.RefinementOperator;
 import org.dllearner.refinementoperators.RhoDRDown;
 import org.dllearner.utilities.Helper;
@@ -219,15 +220,51 @@
 			// capture all instances), but owl:Thing for learning subclasses (since it is
 			// superfluous to add super classes in this case)
 			if(isEquivalenceProblem) {
-				Set<Description> superClasses = reasoner.getClassHierarchy().getSuperClasses(classToDescribe);
-				if(superClasses.size() > 1) {
-					startClass = new Intersection(new LinkedList<Description>(superClasses));
-				} else if(superClasses.size() == 1){
-					startClass = (Description) superClasses.toArray()[0];
+				Set<Description> existingDefinitions = reasoner.getAssertedDefinitions(classToDescribe);
+				if(configurator.getReuseExistingDescription() && (existingDefinitions.size() > 0)) {
+					// the existing definition is reused, which in the simplest case means to
+					// use it as a start class or, if it is already too specific, generalise it
+					
+					// pick the longest existing definition as candidate
+					Description existingDefinition = null;
+					int highestLength = 0;
+					for(Description exDef : existingDefinitions) {
+						if(exDef.getLength() > highestLength) {
+							existingDefinition = exDef;
+							highestLength = exDef.getLength();
+						}
+					}
+					
+					LinkedList<Description> startClassCandidates = new LinkedList<Description>();
+					startClassCandidates.add(existingDefinition);
+					((RhoDRDown)operator).setDropDisjuncts(true);
+					RefinementOperator upwardOperator = new OperatorInverter(operator);
+					
+					// use upward refinement until we find an appropriate start class
+					boolean startClassFound = false;
+					do {
+						Description candidate = startClassCandidates.pollFirst();
+						if(((ClassLearningProblem)learningProblem).getRecall(candidate)<1.0) {
+							// add upward refinements to list
+							startClassCandidates.addAll(upwardOperator.refine(candidate, candidate.getLength()));
+						} else {
+							startClassFound = true;
+						}
+					} while(!startClassFound);
+					
+					((RhoDRDown)operator).setDropDisjuncts(false);
+					
 				} else {
-					startClass = Thing.instance;
-					logger.warn(classToDescribe + " is equivalent to owl:Thing. Usually, it is not " +
-							"sensible to learn a description in this case.");
+					Set<Description> superClasses = reasoner.getClassHierarchy().getSuperClasses(classToDescribe);
+					if(superClasses.size() > 1) {
+						startClass = new Intersection(new LinkedList<Description>(superClasses));
+					} else if(superClasses.size() == 1){
+						startClass = (Description) superClasses.toArray()[0];
+					} else {
+						startClass = Thing.instance;
+						logger.warn(classToDescribe + " is equivalent to owl:Thing. Usually, it is not " +
+								"sensible to learn a description in this case.");
+					}					
 				}
 			}				
 		} else if(learningProblem instanceof PosOnlyLP) {

Modified: trunk/src/dl-learner/org/dllearner/core/ReasonerComponent.java
===================================================================
--- trunk/src/dl-learner/org/dllearner/core/ReasonerComponent.java	2010-02-10 11:57:19 UTC (rev 2004)
+++ trunk/src/dl-learner/org/dllearner/core/ReasonerComponent.java	2010-02-10 12:19:56 UTC (rev 2005)
@@ -263,6 +263,21 @@
 	}	
 	
 	@Override
+	public Set<Description> getAssertedDefinitions(NamedClass namedClass) {
+		try {
+			return getAssertedDefinitionsImpl(namedClass);
+		} catch (ReasoningMethodUnsupportedException e) {
+			handleExceptions(e);
+			return null;
+		}
+	}
+	
+	protected Set<Description> getAssertedDefinitionsImpl(NamedClass namedClass)
+		throws ReasoningMethodUnsupportedException {
+		throw new ReasoningMethodUnsupportedException();
+	}	
+	
+	@Override
 	public final Set<Description> isSuperClassOf(Set<Description> superConcepts,
 			Description subConcept) {
 		reasoningStartTimeTmp = System.nanoTime();

Modified: trunk/src/dl-learner/org/dllearner/core/SchemaReasoner.java
===================================================================
--- trunk/src/dl-learner/org/dllearner/core/SchemaReasoner.java	2010-02-10 11:57:19 UTC (rev 2004)
+++ trunk/src/dl-learner/org/dllearner/core/SchemaReasoner.java	2010-02-10 12:19:56 UTC (rev 2005)
@@ -94,6 +94,13 @@
 	public boolean isEquivalentClass(Description class1, Description class2);	
 		
 	/**
+	 * Returns all asserted owl:equivalence class axioms for the given class.
+	 * @param namedClass A named class in the background knowledge.
+	 * @return A set of descriptions asserted to be equal to the named class.
+	 */
+	public Set<Description> getAssertedDefinitions(NamedClass namedClass);
+	
+	/**
 	 * Checks which of <code>superClasses</code> are super classes of <code>subClass</code>
 	 * @param superClasses A set of (supposed) super classes.
 	 * @param subClasses The (supposed) sub class.

Modified: trunk/src/dl-learner/org/dllearner/reasoning/OWLAPIReasoner.java
===================================================================
--- trunk/src/dl-learner/org/dllearner/reasoning/OWLAPIReasoner.java	2010-02-10 11:57:19 UTC (rev 2004)
+++ trunk/src/dl-learner/org/dllearner/reasoning/OWLAPIReasoner.java	2010-02-10 12:19:56 UTC (rev 2005)
@@ -1111,9 +1111,10 @@
 	 * @param nc the class
 	 * @return the asserted class definitions
 	 */
-	public Set<Description> getAssertedDefinitions(NamedClass nc){
+	@Override
+	public Set<Description> getAssertedDefinitionsImpl(NamedClass nc){
 		OWLClass owlClass = OWLAPIDescriptionConvertVisitor.getOWLDescription(nc).asOWLClass();
-		Set<OWLDescription> OWLAPIDefinitions = owlClass.getEquivalentClasses(new HashSet<OWLOntology>(owlAPIOntologies));
+		Set<OWLDescription> owlAPIDefinitions = owlClass.getEquivalentClasses(new HashSet<OWLOntology>(owlAPIOntologies));
 		
 		// TODO converting to DL-Learner format
 		Set<Description> definitions = new HashSet<Description>();


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