eu.morfeoproject.fast.catalogue.recommender.BuildingBlockRecommender.java Source code

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Here is the source code for eu.morfeoproject.fast.catalogue.recommender.BuildingBlockRecommender.java

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/**
 * Copyright (c) 2008-2011, FAST Consortium
 * 
 * This file is part of FAST Platform.
 * 
 * FAST Platform is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * FAST Platform is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public
 * License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with FAST Platform. If not, see <http://www.gnu.org/licenses/>.
 * 
 * Info about members and contributors of the FAST Consortium
 * is available at http://fast.morfeo-project.eu
 *
 **/
package eu.morfeoproject.fast.catalogue.recommender;

import java.util.ArrayList;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.mahout.common.Pair;
import org.apache.mahout.common.Parameters;
import org.apache.mahout.fpm.pfpgrowth.convertors.string.TopKStringPatterns;
import org.ontoware.rdf2go.model.node.URI;
import org.ontoware.rdf2go.model.node.impl.URIImpl;

import eu.morfeoproject.fast.catalogue.Catalogue;

public abstract class BuildingBlockRecommender implements Recommender {

    protected final Log log = LogFactory.getLog(this.getClass());

    protected Catalogue catalogue;
    protected FPGrowth fpgrowth;
    protected Parameters params = new Parameters();

    public BuildingBlockRecommender(Catalogue catalogue) {
        this.catalogue = catalogue;
    }

    // DEPRECATED: returns the suggestion list as well as the weights for the elements
    //   public List<Pair<URI, Long>> getTopKWeightedList(List<URI> uriList) {
    //      ArrayList<Pair<URI, Long>> pairList = new ArrayList<Pair<URI, Long>>();
    //      TopKStringPatterns topKPatterns = getTopKFrequentPatterns(uriList);
    //      for (Pair<List<String>, Long> pair : topKPatterns.getPatterns()) {
    //         long weight = pair.getSecond();
    //         for (String bb : pair.getFirst()) {
    //            URI u = new URIImpl(bb);
    //            if (!uriList.contains(u)) {
    //               pairList.add(new Pair<URI, Long>(u, weight));
    //               System.out.println(bb+" = "+weight);
    //            }
    //         }
    //      }
    //      return pairList;
    //   }

    public List<URI> getSuggestionList(List<URI> uriList) {
        ArrayList<URI> resultList = new ArrayList<URI>();
        TopKStringPatterns pattern = getTopKStringPatterns(uriList);
        for (Pair<List<String>, Long> pair : pattern.getPatterns()) {
            long weight = pair.getSecond();
            for (String element : pair.getFirst()) {
                URI uri = new URIImpl(element);
                if (!uriList.contains(uri) && !resultList.contains(uri)) {
                    resultList.add(uri);
                    if (log.isInfoEnabled())
                        log.info(uri + ", weight: " + weight);
                }
            }
        }
        return resultList;
    }

    private TopKStringPatterns getTopKStringPatterns(List<URI> uriList) {
        int maxHeapSize = Integer.valueOf(params.get("maxHeapSize", "50"));
        TopKStringPatterns pattern = new TopKStringPatterns();
        TopKStringPatterns partial;
        for (URI uri : uriList) {
            partial = this.fpgrowth.getTopKFrequentPatterns(uri.toString());
            if (partial != null) {
                pattern = pattern.merge(partial, maxHeapSize);
            }
        }
        return pattern;
    }

}