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) 2011
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.List;
import de.lmu.ifi.dbs.elki.data.spatial.SpatialComparable;
import de.lmu.ifi.dbs.elki.database.ids.DBID;
import de.lmu.ifi.dbs.elki.database.query.DistanceResultPair;
import de.lmu.ifi.dbs.elki.database.query.DoubleDistanceResultPair;
import de.lmu.ifi.dbs.elki.database.query.distance.DistanceQuery;
import de.lmu.ifi.dbs.elki.database.query.range.AbstractDistanceRangeQuery;
import de.lmu.ifi.dbs.elki.distance.distancefunction.SpatialPrimitiveDoubleDistanceFunction;
import de.lmu.ifi.dbs.elki.distance.distancevalue.DoubleDistance;
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.DoubleDistanceSearchCandidate;
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.Heap;
/**
* Instance of a range query for a particular spatial index.
*
* @author Erich Schubert
*
* @apiviz.uses AbstractRStarTree
* @apiviz.uses SpatialPrimitiveDoubleDistanceFunction
*/
//TODO: add bulk range queries.
public class DoubleDistanceRStarTreeRangeQuery<O extends SpatialComparable> extends AbstractDistanceRangeQuery<O, DoubleDistance> {
/**
* The index to use
*/
protected final AbstractRStarTree<?, ?> tree;
/**
* Spatial primitive distance function
*/
protected final SpatialPrimitiveDoubleDistanceFunction<? super O> distanceFunction;
/**
* Constructor.
*
* @param tree Index to use
* @param distanceQuery Distance query to use
* @param distanceFunction Distance function
*/
public DoubleDistanceRStarTreeRangeQuery(AbstractRStarTree<?, ?> tree, DistanceQuery<O, DoubleDistance> distanceQuery, SpatialPrimitiveDoubleDistanceFunction<? super O> distanceFunction) {
super(distanceQuery);
this.tree = tree;
this.distanceFunction = distanceFunction;
}
/**
* Perform the actual query process.
*
* @param object Query object
* @param epsilon Query range
* @return Objects contained in query range.
*/
protected List<DistanceResultPair<DoubleDistance>> doRangeQuery(O object, double epsilon) {
final List<DistanceResultPair<DoubleDistance>> result = new ArrayList<DistanceResultPair<DoubleDistance>>();
final Heap<DoubleDistanceSearchCandidate> pq = new Heap<DoubleDistanceSearchCandidate>();
// push root
pq.add(new DoubleDistanceSearchCandidate(0.0, tree.getRootID()));
// search in tree
while(!pq.isEmpty()) {
DoubleDistanceSearchCandidate pqNode = pq.poll();
if(pqNode.mindist > epsilon) {
break;
}
AbstractRStarTreeNode<?, ?> node = tree.getNode(pqNode.nodeID);
final int numEntries = node.getNumEntries();
for(int i = 0; i < numEntries; i++) {
double distance = distanceFunction.doubleMinDist(object, node.getEntry(i));
tree.distanceCalcs++;
if(distance <= epsilon) {
if(node.isLeaf()) {
LeafEntry entry = (LeafEntry) node.getEntry(i);
result.add(new DoubleDistanceResultPair(distance, entry.getDBID()));
}
else {
DirectoryEntry entry = (DirectoryEntry) node.getEntry(i);
pq.add(new DoubleDistanceSearchCandidate(distance, entry.getEntryID()));
}
}
}
}
// sort the result according to the distances
Collections.sort(result);
return result;
}
@Override
public List<DistanceResultPair<DoubleDistance>> getRangeForObject(O obj, DoubleDistance range) {
return doRangeQuery(obj, range.doubleValue());
}
@Override
public List<DistanceResultPair<DoubleDistance>> getRangeForDBID(DBID id, DoubleDistance range) {
return getRangeForObject(relation.get(id), range);
}
}