Examples with UpdatableHeap de.lmu.ifi.dbs.elki.utilities.datastructures.heap.UpdatableHeap used on opensource projects

Example 1 with UpdatableHeap

use of de.lmu.ifi.dbs.elki.utilities.datastructures.heap.UpdatableHeap in project elki by elki-project.

the class FastOPTICS method expandClusterOrder.

/**
 * OPTICS algorithm for processing a point, but with different density
 * estimates
 *
 * @param ipt Point
 * @param order Cluster order (output)
 * @param dq Distance query
 * @param prog Progress for logging.
 */
protected void expandClusterOrder(DBID ipt, ClusterOrder order, DistanceQuery<V> dq, FiniteProgress prog) {
    UpdatableHeap<OPTICSHeapEntry> heap = new UpdatableHeap<>();
    heap.add(new OPTICSHeapEntry(ipt, null, Double.POSITIVE_INFINITY));
    while (!heap.isEmpty()) {
        final OPTICSHeapEntry current = heap.poll();
        DBID currPt = current.objectID;
        order.add(currPt, current.reachability, current.predecessorID);
        processed.add(currPt);
        double coredist = inverseDensities.doubleValue(currPt);
        for (DBIDIter it = neighs.get(currPt).iter(); it.valid(); it.advance()) {
            if (processed.contains(it)) {
                continue;
            }
            double nrdist = dq.distance(currPt, it);
            if (coredist > nrdist) {
                nrdist = coredist;
            }
            if (reachDist.doubleValue(it) == UNDEFINED_DISTANCE) {
                reachDist.put(it, nrdist);
            } else if (nrdist < reachDist.doubleValue(it)) {
                reachDist.put(it, nrdist);
            }
            heap.add(new OPTICSHeapEntry(DBIDUtil.deref(it), currPt, nrdist));
        }
        LOG.incrementProcessed(prog);
    }
}

Example 2 with UpdatableHeap

use of de.lmu.ifi.dbs.elki.utilities.datastructures.heap.UpdatableHeap in project elki by elki-project.

the class MkAppTree method reverseKNNQuery.

/**
 * Performs a reverse k-nearest neighbor query for the given object ID. The
 * query result is in ascending order to the distance to the query object.
 *
 * @param id the query object id
 * @param k the number of nearest neighbors to be returned
 * @return a List of the query results
 */
@Override
public DoubleDBIDList reverseKNNQuery(DBIDRef id, int k) {
    ModifiableDoubleDBIDList result = DBIDUtil.newDistanceDBIDList();
    final Heap<MTreeSearchCandidate> pq = new UpdatableHeap<>();
    // push root
    pq.add(new MTreeSearchCandidate(0., getRootID(), null, Double.NaN));
    // search in tree
    while (!pq.isEmpty()) {
        MTreeSearchCandidate pqNode = pq.poll();
        // FIXME: cache the distance to the routing object in the queue node!
        MkAppTreeNode<O> node = getNode(pqNode.nodeID);
        // directory node
        if (!node.isLeaf()) {
            for (int i = 0; i < node.getNumEntries(); i++) {
                MkAppEntry entry = node.getEntry(i);
                double distance = distance(entry.getRoutingObjectID(), id);
                double minDist = (entry.getCoveringRadius() > distance) ? 0. : distance - entry.getCoveringRadius();
                double approxValue = settings.log ? FastMath.exp(entry.approximatedValueAt(k)) : entry.approximatedValueAt(k);
                if (approxValue < 0) {
                    approxValue = 0;
                }
                if (minDist <= approxValue) {
                    pq.add(new MTreeSearchCandidate(minDist, getPageID(entry), entry.getRoutingObjectID(), Double.NaN));
                }
            }
        } else // data node
        {
            for (int i = 0; i < node.getNumEntries(); i++) {
                MkAppLeafEntry entry = (MkAppLeafEntry) node.getEntry(i);
                double distance = distance(entry.getRoutingObjectID(), id);
                double approxValue = settings.log ? FastMath.exp(entry.approximatedValueAt(k)) : entry.approximatedValueAt(k);
                if (approxValue < 0) {
                    approxValue = 0;
                }
                if (distance <= approxValue) {
                    result.add(distance, entry.getRoutingObjectID());
                }
            }
        }
    }
    return result;
}