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Diffstat (limited to 'src/de/lmu/ifi/dbs/elki/index/tree/spatial/rstarvariants/query/GenericRStarTreeKNNQuery.java')
-rw-r--r-- | src/de/lmu/ifi/dbs/elki/index/tree/spatial/rstarvariants/query/GenericRStarTreeKNNQuery.java | 243 |
1 files changed, 0 insertions, 243 deletions
diff --git a/src/de/lmu/ifi/dbs/elki/index/tree/spatial/rstarvariants/query/GenericRStarTreeKNNQuery.java b/src/de/lmu/ifi/dbs/elki/index/tree/spatial/rstarvariants/query/GenericRStarTreeKNNQuery.java deleted file mode 100644 index 229758ea..00000000 --- a/src/de/lmu/ifi/dbs/elki/index/tree/spatial/rstarvariants/query/GenericRStarTreeKNNQuery.java +++ /dev/null @@ -1,243 +0,0 @@ -package de.lmu.ifi.dbs.elki.index.tree.spatial.rstarvariants.query; - -/* - This file is part of ELKI: - Environment for Developing KDD-Applications Supported by Index-Structures - - Copyright (C) 2013 - Ludwig-Maximilians-Universität München - Lehr- und Forschungseinheit für Datenbanksysteme - ELKI Development Team - - This program 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. - - This program 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 this program. If not, see <http://www.gnu.org/licenses/>. - */ - -import java.util.ArrayList; -import java.util.Collections; -import java.util.HashMap; -import java.util.List; -import java.util.Map; -import java.util.Map.Entry; - -import de.lmu.ifi.dbs.elki.data.spatial.SpatialComparable; -import de.lmu.ifi.dbs.elki.database.ids.ArrayDBIDs; -import de.lmu.ifi.dbs.elki.database.ids.DBID; -import de.lmu.ifi.dbs.elki.database.ids.DBIDIter; -import de.lmu.ifi.dbs.elki.database.ids.DBIDUtil; -import de.lmu.ifi.dbs.elki.database.ids.DBIDs; -import de.lmu.ifi.dbs.elki.database.ids.ModifiableDBIDs; -import de.lmu.ifi.dbs.elki.database.ids.distance.KNNHeap; -import de.lmu.ifi.dbs.elki.database.ids.distance.KNNList; -import de.lmu.ifi.dbs.elki.database.query.distance.SpatialDistanceQuery; -import de.lmu.ifi.dbs.elki.database.query.knn.AbstractDistanceKNNQuery; -import de.lmu.ifi.dbs.elki.distance.DistanceUtil; -import de.lmu.ifi.dbs.elki.distance.distancefunction.SpatialPrimitiveDistanceFunction; -import de.lmu.ifi.dbs.elki.distance.distancevalue.Distance; -import de.lmu.ifi.dbs.elki.index.tree.DirectoryEntry; -import de.lmu.ifi.dbs.elki.index.tree.LeafEntry; -import de.lmu.ifi.dbs.elki.index.tree.query.GenericDistanceSearchCandidate; -import de.lmu.ifi.dbs.elki.index.tree.spatial.SpatialEntry; -import de.lmu.ifi.dbs.elki.index.tree.spatial.rstarvariants.AbstractRStarTree; -import de.lmu.ifi.dbs.elki.index.tree.spatial.rstarvariants.AbstractRStarTreeNode; -import de.lmu.ifi.dbs.elki.utilities.datastructures.heap.ComparableMinHeap; -import de.lmu.ifi.dbs.elki.utilities.documentation.Reference; -import de.lmu.ifi.dbs.elki.utilities.pairs.FCPair; - -/** - * Instance of a KNN query for a particular spatial index. - * - * Reference: - * <p> - * G. R. Hjaltason, H. Samet<br /> - * Ranking in spatial databases<br /> - * In: 4th Symposium on Advances in Spatial Databases, SSD'95 - * </p> - * - * @author Erich Schubert - * - * @apiviz.uses AbstractRStarTree - * @apiviz.uses SpatialPrimitiveDistanceFunction - */ -@Reference(authors = "G. R. Hjaltason, H. Samet", title = "Ranking in spatial databases", booktitle = "Advances in Spatial Databases - 4th Symposium, SSD'95", url = "http://dx.doi.org/10.1007/3-540-60159-7_6") -public class GenericRStarTreeKNNQuery<O extends SpatialComparable, D extends Distance<D>> extends AbstractDistanceKNNQuery<O, D> { - /** - * The index to use - */ - protected final AbstractRStarTree<?, ?, ?> tree; - - /** - * Spatial primitive distance function - */ - protected final SpatialPrimitiveDistanceFunction<? super O, D> distanceFunction; - - /** - * Constructor. - * - * @param tree Index to use - * @param distanceQuery Distance query to use - */ - public GenericRStarTreeKNNQuery(AbstractRStarTree<?, ?, ?> tree, SpatialDistanceQuery<O, D> distanceQuery) { - super(distanceQuery); - this.tree = tree; - this.distanceFunction = distanceQuery.getDistanceFunction(); - } - - /** - * Performs a batch knn query. - * - * @param node the node for which the query should be performed - * @param knnLists a map containing the knn lists for each query objects - */ - protected void batchNN(AbstractRStarTreeNode<?, ?> node, Map<DBID, KNNHeap<D>> knnLists) { - if(node.isLeaf()) { - for(int i = 0; i < node.getNumEntries(); i++) { - SpatialEntry p = node.getEntry(i); - for(Entry<DBID, KNNHeap<D>> ent : knnLists.entrySet()) { - final DBID q = ent.getKey(); - final KNNHeap<D> knns_q = ent.getValue(); - D knn_q_maxDist = knns_q.getKNNDistance(); - - DBID pid = ((LeafEntry) p).getDBID(); - // FIXME: objects are NOT accessible by DBID in a plain rtree context! - D dist_pq = distanceQuery.distance(pid, q); - tree.statistics.countDistanceCalculation(); - if(dist_pq.compareTo(knn_q_maxDist) <= 0) { - knns_q.insert(dist_pq, pid); - } - } - } - } - else { - ModifiableDBIDs ids = DBIDUtil.newArray(knnLists.size()); - for(DBID id : knnLists.keySet()) { - ids.add(id); - } - List<FCPair<D, SpatialEntry>> entries = getSortedEntries(node, ids); - for(FCPair<D, SpatialEntry> distEntry : entries) { - D minDist = distEntry.first; - for(Entry<DBID, KNNHeap<D>> ent : knnLists.entrySet()) { - final KNNHeap<D> knns_q = ent.getValue(); - D knn_q_maxDist = knns_q.getKNNDistance(); - - if(minDist.compareTo(knn_q_maxDist) <= 0) { - SpatialEntry entry = distEntry.second; - AbstractRStarTreeNode<?, ?> child = tree.getNode(((DirectoryEntry) entry).getPageID().intValue()); - batchNN(child, knnLists); - break; - } - } - } - } - } - - /** - * Sorts the entries of the specified node according to their minimum distance - * to the specified objects. - * - * @param node the node - * @param ids the id of the objects - * @return a list of the sorted entries - */ - protected List<FCPair<D, SpatialEntry>> getSortedEntries(AbstractRStarTreeNode<?, ?> node, DBIDs ids) { - List<FCPair<D, SpatialEntry>> result = new ArrayList<>(); - - for(int i = 0; i < node.getNumEntries(); i++) { - SpatialEntry entry = node.getEntry(i); - D minMinDist = distanceQuery.getDistanceFactory().infiniteDistance(); - for(DBIDIter iter = ids.iter(); iter.valid(); iter.advance()) { - D minDist = distanceFunction.minDist(entry, relation.get(iter)); - tree.statistics.countDistanceCalculation(); - minMinDist = DistanceUtil.min(minDist, minMinDist); - } - result.add(new FCPair<>(minMinDist, entry)); - } - - Collections.sort(result); - return result; - } - - @Override - public KNNList<D> getKNNForObject(O obj, int k) { - final KNNHeap<D> knnList = DBIDUtil.newHeap(distanceFunction.getDistanceFactory(), k); - final ComparableMinHeap<GenericDistanceSearchCandidate<D>> pq = new ComparableMinHeap<>(Math.min(knnList.getK() << 1, 20)); - tree.statistics.countKNNQuery(); - - // push root - pq.add(new GenericDistanceSearchCandidate<>(distanceFunction.getDistanceFactory().nullDistance(), tree.getRootID())); - D maxDist = distanceFunction.getDistanceFactory().infiniteDistance(); - - // search in tree - while(!pq.isEmpty()) { - GenericDistanceSearchCandidate<D> pqNode = pq.poll(); - - if(pqNode.mindist.compareTo(maxDist) > 0) { - break; - } - maxDist = expandNode(obj, knnList, pq, maxDist, pqNode.nodeID); - } - return knnList.toKNNList(); - } - - private D expandNode(O object, KNNHeap<D> knnList, final ComparableMinHeap<GenericDistanceSearchCandidate<D>> pq, D maxDist, final int nodeID) { - AbstractRStarTreeNode<?, ?> node = tree.getNode(nodeID); - // data node - if(node.isLeaf()) { - for(int i = 0; i < node.getNumEntries(); i++) { - SpatialEntry entry = node.getEntry(i); - D distance = distanceFunction.minDist(entry, object); - tree.statistics.countDistanceCalculation(); - if(distance.compareTo(maxDist) <= 0) { - knnList.insert(distance, ((LeafEntry) entry).getDBID()); - maxDist = knnList.getKNNDistance(); - } - } - } - // directory node - else { - for(int i = 0; i < node.getNumEntries(); i++) { - SpatialEntry entry = node.getEntry(i); - D distance = distanceFunction.minDist(entry, object); - tree.statistics.countDistanceCalculation(); - // Greedy expand, bypassing the queue - if(distance.isNullDistance()) { - expandNode(object, knnList, pq, maxDist, ((DirectoryEntry) entry).getPageID()); - } - else { - if(distance.compareTo(maxDist) <= 0) { - pq.add(new GenericDistanceSearchCandidate<>(distance, ((DirectoryEntry) entry).getPageID())); - } - } - } - } - return maxDist; - } - - @Override - public List<KNNList<D>> getKNNForBulkDBIDs(ArrayDBIDs ids, int k) { - // While this works, it seems to be slow at least for large sets! - final Map<DBID, KNNHeap<D>> knnLists = new HashMap<>(ids.size()); - for(DBIDIter iter = ids.iter(); iter.valid(); iter.advance()) { - knnLists.put(DBIDUtil.deref(iter), DBIDUtil.newHeap(distanceFunction.getDistanceFactory(), k)); - } - - batchNN(tree.getRoot(), knnLists); - - List<KNNList<D>> result = new ArrayList<>(); - for(DBIDIter iter = ids.iter(); iter.valid(); iter.advance()) { - tree.statistics.countKNNQuery(); - result.add(knnLists.get(DBIDUtil.deref(iter)).toKNNList()); - } - return result; - } -} |