package de.lmu.ifi.dbs.elki.result.optics;
/*
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 de.lmu.ifi.dbs.elki.database.ids.DBID;
import de.lmu.ifi.dbs.elki.distance.distancevalue.DoubleDistance;
/**
* Provides an entry in a cluster order.
*
* @author Elke Achtert
*/
public class DoubleDistanceClusterOrderEntry implements Comparable<ClusterOrderEntry<DoubleDistance>>, ClusterOrderEntry<DoubleDistance> {
/**
* The id of the entry.
*/
private DBID objectID;
/**
* The id of the entry's predecessor.
*/
private DBID predecessorID;
/**
* The reachability of the entry.
*/
private double reachability;
/**
* Creates a new entry in a cluster order with the specified parameters.
*
* @param objectID the id of the entry
* @param predecessorID the id of the entry's predecessor
* @param reachability the reachability of the entry
*/
public DoubleDistanceClusterOrderEntry(DBID objectID, DBID predecessorID, double reachability) {
this.objectID = objectID;
this.predecessorID = predecessorID;
this.reachability = reachability;
}
/**
* Indicates whether some other object is "equal to" this one.
*
* NOTE: for the use in an UpdatableHeap, only the ID is compared!
*
* @param o the reference object with which to compare.
* @return <code>true</code> if this object has the same attribute values as
* the o argument; <code>false</code> otherwise.
*/
@Override
public boolean equals(Object o) {
if(this == o) {
return true;
}
if(o == null || !(o instanceof ClusterOrderEntry)) {
return false;
}
final ClusterOrderEntry<?> that = (ClusterOrderEntry<?>) o;
// Compare by ID only, for UpdatableHeap!
return objectID.equals(that.getID());
}
/**
* Returns a hash code value for the object.
*
* @return the object id if this entry
*/
@Override
public int hashCode() {
return objectID.hashCode();
}
/**
* Returns a string representation of the object.
*
* @return a string representation of the object.
*/
@Override
public String toString() {
return objectID + "(" + predecessorID + "," + reachability + ")";
}
/**
* Returns the object id of this entry.
*
* @return the object id of this entry
*/
@Override
public DBID getID() {
return objectID;
}
/**
* Returns the id of the predecessor of this entry if this entry has a
* predecessor, null otherwise.
*
* @return the id of the predecessor of this entry
*/
@Override
public DBID getPredecessorID() {
return predecessorID;
}
/**
* Returns the reachability distance of this entry
*
* @return the reachability distance of this entry
*/
@Override
public DoubleDistance getReachability() {
return new DoubleDistance(reachability);
}
@Override
public int compareTo(ClusterOrderEntry<DoubleDistance> o) {
if(o instanceof DoubleDistanceClusterOrderEntry) {
int delta = Double.compare(this.reachability, ((DoubleDistanceClusterOrderEntry) o).reachability);
if(delta != 0) {
return delta;
}
}
else {
int delta = this.getReachability().compareTo(o.getReachability());
if(delta != 0) {
return delta;
}
}
return -getID().compareTo(o.getID());
}
}