/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2006-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library 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
* Lesser General Public License for more details.
*/
package org.geotools.graph.util.delaunay;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Vector;
import java.util.logging.Logger;
import org.geotools.graph.structure.Edge;
import org.geotools.graph.structure.Graph;
import org.geotools.graph.structure.Node;
import org.geotools.graph.structure.basic.BasicGraph;
/**
*
* This class implements the AUTOCLUST algorithm of Estivill-Castro and Lee (2002)
* "Argument free clustering for large spatial point-data sets via boundary extraction
* from Delaunay Diagram" in Computers, Environment and Urban Systems, 26:315-334.
*
* @author jfc173
*
*
* @source $URL$
*/
public class AutoClust {
private static final Logger LOGGER = org.geotools.util.logging.Logging.getLogger("org.geotools.graph");
/** Creates a new instance of AutoClust */
public AutoClust() {
}
public static Graph runAutoClust(Graph d){
//this is assuming d is a delaunay triangulation. If it isn't, results are unspecified.
//Such a diagram can be obtained through org.geotools.graph.util.delaunay.DelaunayTriangulator.
HashMap map = new HashMap();
Collection nodes = d.getNodes();
Collection edges = d.getEdges();
showGraph(nodes, edges, 0);
Iterator nodeIt = nodes.iterator();
double[] localDevs = new double[nodes.size()];
int index = 0;
while (nodeIt.hasNext()){
DelaunayNode next = (DelaunayNode) nodeIt.next();
AutoClustData acd = new AutoClustData();
List localEdges = AutoClustUtils.findAdjacentEdges(next, edges);
double totalLength = 0;
Iterator edgeIt = localEdges.iterator();
while (edgeIt.hasNext()){
DelaunayEdge nextEdge = (DelaunayEdge) edgeIt.next();
totalLength = totalLength + nextEdge.getEuclideanDistance();
}
double meanLength = totalLength/localEdges.size();
double sumOfSquaredDiffs = 0;
Iterator anotherEdgeIt = localEdges.iterator();
while (anotherEdgeIt.hasNext()){
DelaunayEdge nextEdge = (DelaunayEdge) anotherEdgeIt.next();
sumOfSquaredDiffs = sumOfSquaredDiffs + Math.pow((nextEdge.getEuclideanDistance() - meanLength), 2);
}
double variance = sumOfSquaredDiffs/(localEdges.size());
double stDev = Math.sqrt(variance);
localDevs[index] = stDev;
index++;
acd.setLocalMean(meanLength);
acd.setLocalStDev(stDev);
map.put(next, acd);
}
double total = 0;
for (int i = 0; i < localDevs.length; i++){
total = total + localDevs[i];
}
double meanStDev = total/localDevs.length;
//these three are for coloring the graph in the poster, not for algorithmic purposes
Vector allShortEdges = new Vector();
Vector allLongEdges = new Vector();
Vector allOtherEdges = new Vector();
Iterator anotherNodeIt = nodes.iterator();
while (anotherNodeIt.hasNext()){
DelaunayNode next = (DelaunayNode) anotherNodeIt.next();
List localEdges = AutoClustUtils.findAdjacentEdges(next, edges);
AutoClustData acd = (AutoClustData) map.get(next);
Iterator edgeIt = localEdges.iterator();
Vector shortEdges = new Vector();
Vector longEdges = new Vector();
Vector otherEdges = new Vector();
LOGGER.fine("local mean is " + acd.getLocalMean());
LOGGER.fine("mean st dev is " + meanStDev);
while (edgeIt.hasNext()){
DelaunayEdge nextEdge = (DelaunayEdge) edgeIt.next();
double length = nextEdge.getEuclideanDistance();
if (length < acd.getLocalMean() - meanStDev){
shortEdges.add(nextEdge);
LOGGER.finer(nextEdge + ": length " + nextEdge.getEuclideanDistance() + " is short");
} else if (length > acd.getLocalMean() + meanStDev){
longEdges.add(nextEdge);
LOGGER.finer(nextEdge + ": length " + nextEdge.getEuclideanDistance() + " is long");
} else {
otherEdges.add(nextEdge);
LOGGER.finer(nextEdge + ": length " + nextEdge.getEuclideanDistance() + " is medium");
}
}
acd.setShortEdges(shortEdges);
acd.setLongEdges(longEdges);
acd.setOtherEdges(otherEdges);
allLongEdges.addAll(longEdges);
allShortEdges.addAll(shortEdges);
allOtherEdges.addAll(otherEdges);
}
//for the poster
Graph gp = new BasicGraph(nodes, edges);
javax.swing.JFrame frame = new javax.swing.JFrame();
GraphViewer viewer = new GraphViewer();
viewer.setLongEdges(allLongEdges);
viewer.setShortEdges(allShortEdges);
viewer.setOtherEdges(allOtherEdges);
viewer.setColorEdges(true);
viewer.setGraph(gp);
frame.getContentPane().add(viewer);
frame.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE);
frame.setSize(new java.awt.Dimension(800, 800));
frame.setTitle("Assigned edge categories");
frame.setVisible(true);
//Phase I
Iterator nodeIt3 = nodes.iterator();
while (nodeIt3.hasNext()){
DelaunayNode next = (DelaunayNode) nodeIt3.next();
AutoClustData acd = (AutoClustData) map.get(next);
List shortEdges = acd.getShortEdges();
List longEdges = acd.getLongEdges();
edges.removeAll(shortEdges);
LOGGER.finer("removed " + shortEdges);
edges.removeAll(longEdges);
LOGGER.finer("removed " + longEdges);
}
LOGGER.fine("End of phase one and ");
LOGGER.fine("Nodes are " + nodes);
LOGGER.fine("Edges are " + edges);
showGraph(nodes, edges, 1);
Vector connectedComponents = AutoClustUtils.findConnectedComponents(nodes, edges);
//Phase II
Iterator nodeIt4 = nodes.iterator();
while (nodeIt4.hasNext()){
DelaunayNode next = (DelaunayNode) nodeIt4.next();
AutoClustData acd = (AutoClustData) map.get(next);
List shortEdges = acd.getShortEdges();
if (!(shortEdges.isEmpty())){
Vector shortlyConnectedComponents = new Vector();
Iterator shortIt = shortEdges.iterator();
while (shortIt.hasNext()){
Edge nextEdge = (Edge) shortIt.next();
Node other = nextEdge.getOtherNode(next);
Graph g = getMyComponent(other, connectedComponents);
if (!(shortlyConnectedComponents.contains(g))){
shortlyConnectedComponents.add(g);
}
}
Graph cv = null;
if (shortlyConnectedComponents.size() > 1){
Iterator sccIt = shortlyConnectedComponents.iterator();
int maxSize = 0;
while (sccIt.hasNext()){
Graph nextGraph = (Graph) sccIt.next();
int size = nextGraph.getNodes().size();
if (size > maxSize){
maxSize = size;
cv = nextGraph;
}
}
} else {
cv = (Graph) shortlyConnectedComponents.get(0);
}
Iterator shortIt2 = shortEdges.iterator();
while (shortIt2.hasNext()){
Edge nextEdge = (Edge) shortIt2.next();
Node other = nextEdge.getOtherNode(next);
if (cv.equals(getMyComponent(other, shortlyConnectedComponents))){
edges.add(nextEdge);
}
}
} //end if shortEdges isn't empty
Graph gr = getMyComponent(next, connectedComponents);
if (gr.getNodes().size() == 1){
Vector shortlyConnectedComponents = new Vector();
Iterator shortIt = shortEdges.iterator();
while (shortIt.hasNext()){
Edge nextEdge = (Edge) shortIt.next();
Node other = nextEdge.getOtherNode(next);
Graph g = getMyComponent(other, connectedComponents);
if (!(shortlyConnectedComponents.contains(g))){
shortlyConnectedComponents.add(g);
}
}
if (shortlyConnectedComponents.size() == 1){
edges.addAll(shortEdges);
}
}
} //end nodeIt4 while loop.
LOGGER.fine("End of phase two and ");
LOGGER.fine("Nodes are " + nodes);
LOGGER.fine("Edges are " + edges);
showGraph(nodes, edges, 2);
connectedComponents = AutoClustUtils.findConnectedComponents(nodes, edges);
//Phase III
Iterator nodeIt5 = nodes.iterator();
while (nodeIt5.hasNext()){
DelaunayNode next = (DelaunayNode) nodeIt5.next();
Vector edgesWithinTwo = new Vector();
List adjacentEdges = AutoClustUtils.findAdjacentEdges(next, edges); //yes, next.getEdges() could work, but there's no guarantee that next's edge list is current anymore
edgesWithinTwo.addAll(adjacentEdges);
Iterator adjacentIt = adjacentEdges.iterator();
while (adjacentIt.hasNext()){
Edge nextEdge = (Edge) adjacentIt.next();
Node other = nextEdge.getOtherNode(next);
List adjacentToOther = AutoClustUtils.findAdjacentEdges(other, edges); //yes, other.getEdges() could work, but there's no guarantee that other's edge list is current anymore
Iterator atoIt = adjacentToOther.iterator();
while (atoIt.hasNext()){
Edge nextEdge2 = (Edge) atoIt.next();
if (!(edgesWithinTwo.contains(nextEdge2))){
edgesWithinTwo.add(nextEdge2);
}
}
}
double totalLength = 0;
Iterator ewtIt = edgesWithinTwo.iterator();
while (ewtIt.hasNext()){
totalLength = totalLength + ((DelaunayEdge) ewtIt.next()).getEuclideanDistance();
}
double local2Mean = totalLength/edgesWithinTwo.size();
Iterator ewtIt2 = edgesWithinTwo.iterator();
while (ewtIt2.hasNext()){
DelaunayEdge dEdge = (DelaunayEdge) ewtIt2.next();
if (dEdge.getEuclideanDistance() > (local2Mean + meanStDev)){
edges.remove(dEdge);
}
}
} //end nodeIt5 loop
LOGGER.fine("End of phase three and ");
LOGGER.fine("Nodes are " + nodes);
LOGGER.fine("Edges are " + edges);
showGraph(nodes, edges, 3);
connectedComponents = AutoClustUtils.findConnectedComponents(nodes, edges);
return new BasicGraph(nodes, edges);
}
private static Graph getMyComponent(Node node, Vector components){
Iterator it = components.iterator();
Graph ret = null;
boolean found = false;
while ((it.hasNext()) && (!(found))){
Graph next = (Graph) it.next();
if (next.getNodes().contains(node)){
found = true;
ret = next;
}
}
if (ret == null){
throw new RuntimeException("Couldn't find the graph component containing node: " + node);
}
return ret;
}
private static void showGraph(Collection nodes, Collection edges, int phase){
Graph g = new BasicGraph(nodes, edges);
javax.swing.JFrame frame = new javax.swing.JFrame();
GraphViewer viewer = new GraphViewer();
viewer.setGraph(g);
frame.getContentPane().add(viewer);
frame.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE);
frame.setSize(new java.awt.Dimension(800, 800));
frame.setTitle("Phase " + phase);
frame.setVisible(true);
}
}