[DL-Learner SVN] SF.net SVN: dl-learner:[3487] trunk/components-core/src/main/java/org/ dllearner/utilities/GreedyCohaerencyExtractor.java

[<lor...@us...>]

Revision: 3487
          http://dl-learner.svn.sourceforge.net/dl-learner/?rev=3487&view=rev
Author:   lorenz_b
Date:     2011-12-07 21:50:12 +0000 (Wed, 07 Dec 2011)
Log Message:
-----------
Started greedy algorithm implementation to build cohaerent ontology.

Added Paths:
-----------
    trunk/components-core/src/main/java/org/dllearner/utilities/GreedyCohaerencyExtractor.java

Added: trunk/components-core/src/main/java/org/dllearner/utilities/GreedyCohaerencyExtractor.java
===================================================================
--- trunk/components-core/src/main/java/org/dllearner/utilities/GreedyCohaerencyExtractor.java	                        (rev 0)
+++ trunk/components-core/src/main/java/org/dllearner/utilities/GreedyCohaerencyExtractor.java	2011-12-07 21:50:12 UTC (rev 3487)
@@ -0,0 +1,99 @@
+package org.dllearner.utilities;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import org.apache.commons.collections15.BidiMap;
+import org.apache.commons.collections15.bidimap.DualHashBidiMap;
+import org.semanticweb.owlapi.apibinding.OWLManager;
+import org.semanticweb.owlapi.model.AxiomType;
+import org.semanticweb.owlapi.model.OWLAxiom;
+import org.semanticweb.owlapi.model.OWLOntology;
+import org.semanticweb.owlapi.model.OWLOntologyCreationException;
+import org.semanticweb.owlapi.model.OWLOntologyManager;
+import org.semanticweb.owlapi.reasoner.OWLReasoner;
+
+public class GreedyCohaerencyExtractor {
+	
+	public GreedyCohaerencyExtractor() {
+		// TODO Auto-generated constructor stub
+	}
+	
+	public OWLOntology getCoharentOntology(OWLOntology ontology) throws OWLOntologyCreationException{
+		BidiMap<AxiomType<? extends OWLAxiom>, Integer> axiomType2CountMap = getAxiomTypeCount(ontology);
+		
+		Map<AxiomType<? extends OWLAxiom>, List<OWLAxiom>> axiomType2AxiomsMap = new HashMap<AxiomType<? extends OWLAxiom>, List<OWLAxiom>>();
+		for(AxiomType<? extends OWLAxiom> type : AxiomType.AXIOM_TYPES){
+			axiomType2AxiomsMap.put(type, new ArrayList<OWLAxiom>(ontology.getAxioms(type)));
+		}
+		
+		int lcm = lcm(new ArrayList<Integer>(axiomType2CountMap.values()));
+		
+		OWLOntologyManager man = OWLManager.createOWLOntologyManager();
+		OWLOntology cohaerentOntology = man.createOntology();
+		
+		for(int i = 0; i < lcm; i++){
+			for(Entry<AxiomType<? extends OWLAxiom>, Integer> entry : axiomType2CountMap.entrySet()){
+				if((i % entry.getValue()) == 0){
+					man.addAxiom(cohaerentOntology, axiomType2AxiomsMap.get(entry.getKey()).remove(0));
+				}
+			}
+		}
+		return cohaerentOntology;
+	}
+	
+	public OWLOntology getCoharentOntology(OWLReasoner reasoner) throws OWLOntologyCreationException{
+		return getCoharentOntology(reasoner.getRootOntology());
+	}
+	
+	private BidiMap<AxiomType<? extends OWLAxiom>, Integer> getAxiomTypeCount(OWLOntology ontology){
+		BidiMap<AxiomType<? extends OWLAxiom>, Integer> axiomType2CountMap = new DualHashBidiMap<AxiomType<? extends OWLAxiom>, Integer>();
+		
+		for(AxiomType<? extends OWLAxiom> type : AxiomType.AXIOM_TYPES){
+			axiomType2CountMap.put(type, ontology.getAxiomCount(type));
+		}
+		
+		return axiomType2CountMap;
+	}
+	
+	private int lcm(int x1,int x2) {
+	      if(x1<=0 || x2<=0) {
+	          throw new IllegalArgumentException("Cannot compute the least "+
+	                                             "common multiple of two "+
+	                                             "numbers if one, at least,"+
+	                                             "is negative.");
+	      }
+	      int max,min;
+	      if (x1>x2) {
+	          max = x1;
+	          min = x2;
+	      } else {
+	          max = x2;
+	          min = x1;
+	      }
+	      for(int i=1; i<=min; i++) {
+	          if( (max*i)%min == 0 ) {
+	              return i*max;
+	          }
+	      }
+	      throw new Error("Cannot find the least common multiple of numbers "+
+	                      x1+" and "+x2);
+	  }
+	
+	private int lcm(List<Integer> values) {
+		if(values.size() == 1){
+			return values.get(0);
+		} else {
+			List<Integer> list = new ArrayList<Integer>();
+			list.add(lcm(values.get(0), values.get(1)));
+			if(values.size() > 2){
+				list.addAll(values.subList(2, values.size()));
+			}
+			return lcm(list);
+		}
+	}
+
+}


Property changes on: trunk/components-core/src/main/java/org/dllearner/utilities/GreedyCohaerencyExtractor.java
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Added: svn:mime-type
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