001/** 002 * Copyright (C) 2007 - 2016, Jens Lehmann 003 * 004 * This file is part of DL-Learner. 005 * 006 * DL-Learner is free software; you can redistribute it and/or modify 007 * it under the terms of the GNU General Public License as published by 008 * the Free Software Foundation; either version 3 of the License, or 009 * (at your option) any later version. 010 * 011 * DL-Learner is distributed in the hope that it will be useful, 012 * but WITHOUT ANY WARRANTY; without even the implied warranty of 013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 014 * GNU General Public License for more details. 015 * 016 * You should have received a copy of the GNU General Public License 017 * along with this program. If not, see <http://www.gnu.org/licenses/>. 018 */ 019package org.dllearner.algorithms.properties; 020 021import java.util.SortedSet; 022 023import org.dllearner.core.ComponentAnn; 024import org.dllearner.core.EvaluatedAxiom; 025import org.dllearner.kb.SparqlEndpointKS; 026import org.dllearner.kb.sparql.SparqlEndpoint; 027import org.dllearner.learningproblems.AxiomScore; 028import org.semanticweb.owlapi.model.AxiomType; 029import org.semanticweb.owlapi.model.IRI; 030import org.semanticweb.owlapi.model.OWLInverseObjectPropertiesAxiom; 031import org.semanticweb.owlapi.model.OWLObjectProperty; 032 033import uk.ac.manchester.cs.owl.owlapi.OWLDataFactoryImpl; 034 035import org.apache.jena.query.ParameterizedSparqlString; 036import org.apache.jena.query.QuerySolution; 037import org.apache.jena.query.ResultSet; 038 039@ComponentAnn(name = "inverse object property axiom learner", shortName = "oplinv", version = 0.1, description="A learning algorithm for inverse object property axioms.") 040public class InverseObjectPropertyAxiomLearner extends 041 ObjectPropertyAxiomLearner<OWLInverseObjectPropertiesAxiom> { 042 043 private static final ParameterizedSparqlString POS_EXAMPLES_QUERY = new ParameterizedSparqlString( 044 "SELECT ?p_inv ?s ?o WHERE { ?s ?p ?o . ?o ?p_inv ?s . FILTER(!sameTerm(?p, ?p_inv))}"); 045 046 private static final ParameterizedSparqlString NEG_EXAMPLES_QUERY = new ParameterizedSparqlString( 047 "SELECT ?p_inv ?s ?o WHERE { ?s ?p ?o . FILTER NOT EXISTS {?o ?p_inv ?s . FILTER(!sameTerm(?p, ?p_inv))}}"); 048 049 private static final ParameterizedSparqlString QUERY = new ParameterizedSparqlString( 050 "SELECT ?p_inv (COUNT(*) AS ?cnt) WHERE { ?s ?p ?o . ?o ?p_inv ?s . FILTER(!sameTerm(?p, ?p_inv))} GROUP BY ?p_inv"); 051 052 private static final ParameterizedSparqlString SAMPLE_QUERY = new ParameterizedSparqlString( 053 "CONSTRUCT {?s ?p ?o . ?o ?p_inv ?s . } WHERE {?s ?p ?o . OPTIONAL{ ?o ?p_inv ?s . FILTER(!sameTerm(?p, ?p_inv))}}"); 054 055 public InverseObjectPropertyAxiomLearner(SparqlEndpointKS ks) { 056 super.ks = ks; 057 058 super.posExamplesQueryTemplate = POS_EXAMPLES_QUERY; 059 super.negExamplesQueryTemplate = NEG_EXAMPLES_QUERY; 060 061 axiomType = AxiomType.INVERSE_OBJECT_PROPERTIES; 062 } 063 064 /* (non-Javadoc) 065 * @see org.dllearner.algorithms.properties.PropertyAxiomLearner#setEntityToDescribe(org.semanticweb.owlapi.model.OWLProperty) 066 */ 067 @Override 068 public void setEntityToDescribe(OWLObjectProperty entityToDescribe) { 069 super.setEntityToDescribe(entityToDescribe); 070 071 QUERY.setIri("p", entityToDescribe.toStringID()); 072 } 073 074 /* (non-Javadoc) 075 * @see org.dllearner.algorithms.properties.PropertyAxiomLearner#getSampleQuery() 076 */ 077 @Override 078 protected ParameterizedSparqlString getSampleQuery() { 079 return SAMPLE_QUERY; 080 } 081 082 /* (non-Javadoc) 083 * @see org.dllearner.core.AbstractAxiomLearningAlgorithm#getExistingAxioms() 084 */ 085 @Override 086 protected void getExistingAxioms() { 087 SortedSet<OWLObjectProperty> existingInverseObjectProperties = reasoner 088 .getInverseObjectProperties(entityToDescribe); 089 for (OWLObjectProperty invProp : existingInverseObjectProperties) { 090 existingAxioms.add(df.getOWLInverseObjectPropertiesAxiom(invProp, entityToDescribe)); 091 } 092 } 093 094 /* (non-Javadoc) 095 * @see org.dllearner.algorithms.properties.PropertyAxiomLearner#run() 096 */ 097 @Override 098 protected void run() { 099 ResultSet rs = executeSelectQuery(QUERY.toString()); 100 QuerySolution qs; 101 while (rs.hasNext()) { 102 qs = rs.next(); 103 104 // candidate 105 OWLObjectProperty candidate = df.getOWLObjectProperty(IRI.create(qs.getResource("p_inv").getURI())); 106 107 // frequency 108 int frequency = qs.getLiteral("cnt").getInt(); 109 110 // score 111 AxiomScore score = computeScore(popularity, frequency, useSampling); 112 113 currentlyBestAxioms.add(new EvaluatedAxiom<>(df 114 .getOWLInverseObjectPropertiesAxiom(entityToDescribe, candidate), score 115 )); 116 } 117 } 118 119 public static void main(String[] args) throws Exception { 120 SparqlEndpointKS ks = new SparqlEndpointKS(SparqlEndpoint.getEndpointDBpedia()); 121 122 InverseObjectPropertyAxiomLearner l = new InverseObjectPropertyAxiomLearner(ks); 123 l.setEntityToDescribe(new OWLDataFactoryImpl().getOWLObjectProperty(IRI 124 .create("http://dbpedia.org/ontology/routeEnd"))); 125 l.setMaxExecutionTimeInSeconds(60); 126 // l.setForceSPARQL_1_0_Mode(true); 127 // l.setReturnOnlyNewAxioms(true); 128 l.init(); 129 l.start(); 130 131 System.out.println(l.getCurrentlyBestEvaluatedAxioms(10, 0.2)); 132 } 133 134 135 136}