/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, 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;
import java.util.ArrayList;
import java.util.HashMap;
import org.geotools.graph.build.GraphBuilder;
import org.geotools.graph.build.GraphGenerator;
import org.geotools.graph.build.opt.OptDirectedGraphBuilder;
import org.geotools.graph.build.opt.OptGraphBuilder;
import org.geotools.graph.structure.Edge;
import org.geotools.graph.structure.GraphVisitor;
import org.geotools.graph.structure.Graphable;
import org.geotools.graph.structure.Node;
import org.geotools.graph.structure.opt.OptDirectedNode;
import org.geotools.graph.structure.opt.OptNode;
import org.geotools.graph.util.FIFOQueue;
/**
*
*
* @source $URL$
*/
public class GraphTestUtil {
/**
* Builds a graph with no bifurcations made up of a specified number of nodes.
* Nodes are numbered from 0 to (# of nodes - 1).<BR>
* <BR>
* O----O----O--...--O----O----O
*
* @param builder Builder to use to construct graph.
* @param nnodes Number of nodes in graph.
*
* @return 2 element object array containing references to the end points of
* the graph. (The nodes of degree 1 at the end of the graph.
*/
public static Node[] buildNoBifurcations(GraphBuilder builder, int nnodes) {
Node n1 = builder.buildNode();
builder.addNode(n1);
n1.setID(0);
Node n2 = null;
Edge e = null;
Node first = n1;
for (int i = 1; i < nnodes; i++) {
n2 = builder.buildNode();
builder.addNode(n2);
n2.setID(i);
e = builder.buildEdge(n1,n2);
builder.addEdge(e);
e.setID(i-1);
n1 = n2;
}
return(new Node[]{first,n1});
}
public static Node[] buildNoBifurcations(GraphGenerator gen, int nnodes) {
String[] nodes = new String[nnodes];
Node[] ends = new Node[2];
for (int i = 0; i < nnodes; i++) {
nodes[i] = new String(String.valueOf(i));
if (i > 0) {
Edge e = (Edge)gen.add(new String[]{nodes[i-1], nodes[i]});
if (i == 1) ends[0] = e.getNodeA();
if (i == nnodes-1) ends[1] = e.getNodeB();
}
}
return(ends);
}
public static Object[] buildNoBifurcations(
OptGraphBuilder builder, int nnodes
) {
//use maps for id since optimized graphable doesn't use id's
HashMap node2id = new HashMap();
HashMap edge2id = new HashMap();
OptNode n1 = (OptNode)builder.buildNode();
n1.setDegree(1);
builder.addNode(n1);
node2id.put(n1, new Integer(0));
OptNode n2 = null;
Edge e = null;
OptNode first = n1;
for (int i = 1; i < nnodes; i++) {
n2 = (OptNode)builder.buildNode();
if (i < nnodes-1) n2.setDegree(2);
else n2.setDegree(1);
builder.addNode(n2);
node2id.put(n2, new Integer(i));
e = builder.buildEdge(n1,n2);
builder.addEdge(e);
edge2id.put(e, new Integer(i-1));
n1 = n2;
}
return(new Object[]{first,n1, node2id, edge2id});
}
public static Object[] buildNoBifurcations(
OptDirectedGraphBuilder builder, int nnodes
) {
//use maps for id since optimized graphable doesn't use id's
HashMap node2id = new HashMap();
HashMap edge2id = new HashMap();
OptDirectedNode n1 = (OptDirectedNode)builder.buildNode();
n1.setInDegree(0);
n1.setOutDegree(1);
builder.addNode(n1);
node2id.put(n1, new Integer(0));
OptDirectedNode n2 = null;
Edge e = null;
OptDirectedNode first = n1;
for (int i = 1; i < nnodes; i++) {
n2 = (OptDirectedNode)builder.buildNode();
if (i < nnodes-1) {
n2.setInDegree(1);
n2.setOutDegree(1);
}
else {
n2.setInDegree(1);
n2.setOutDegree(0);
}
builder.addNode(n2);
node2id.put(n2, new Integer(i));
e = builder.buildEdge(n1,n2);
builder.addEdge(e);
edge2id.put(e, new Integer(i-1));
n1 = n2;
}
return(new Object[]{first,n1, node2id, edge2id});
}
public static Node[] buildSingleBifurcation(
final GraphBuilder builder, int nnodes, final int bifurcation
) {
Node[] ends = buildNoBifurcations(builder, nnodes-1);
final Node n = builder.buildNode();
final ArrayList bif = new ArrayList();
builder.getGraph().visitNodes(
new GraphVisitor() {
public int visit(Graphable component) {
if (component.getID() == bifurcation) {
bif.add(component);
}
return(0);
}
}
);
Edge e = builder.buildEdge(n, (Node) bif.get(0));
builder.addNode(n);
builder.addEdge(e);
Node[] bifends = new Node[]{ends[0], ends[1], (Node)bif.get(0)};
return(bifends);
}
/**
* Creates a balanced binary tree consisting of a specefied number of levels.
* Each node created contains a string representing the nodes location in
* the tree.<BR>
* <BR>
* locstring(root) = "0";
* locstring(node) = locstring(parent) + ".0" (if left child);
* locstring(node) = locstring(parent) + ".1" (if right child);
*
* @param builder Builder to construct graph with
* @param levels Number of levels in the tree.
*
* @return A 2 element object array.
* 0 = root node
* 1 = map of locstring to node
*/
public static Object[] buildPerfectBinaryTree(
GraphBuilder builder, int levels
) {
HashMap id2node = new HashMap();
//a balanced binary tree
Node root = builder.buildNode();
root.setObject(new String("0"));
id2node.put(root.getObject(), root);
builder.addNode(root);
FIFOQueue queue = new FIFOQueue((int)Math.pow(2, levels+1));
queue.enq(root);
//build a complete binary tree
// number of nodes = 2^(n+1) - 1
int level = 0;
while (level < levels) {
int nnodes = (int)Math.pow(2, level);
for (int i = 0; i < nnodes; i++) {
Node n = (Node)queue.deq();
Node ln = builder.buildNode();
ln.setObject(n.getObject() + ".0");
id2node.put(ln.getObject(), ln);
Node rn = builder.buildNode();
rn.setObject(n.getObject() + ".1");
id2node.put(rn.getObject(), rn);
Edge le = builder.buildEdge(n, ln);
Edge re = builder.buildEdge(n, rn);
builder.addNode(ln);
builder.addNode(rn);
builder.addEdge(le);
builder.addEdge(re);
queue.enq(ln);
queue.enq(rn);
}
level++;
}
return(new Object[]{root, id2node});
}
public static Object[] buildPerfectBinaryTree(
OptGraphBuilder builder, int levels
) {
OptNode root = (OptNode)builder.buildNode();
root.setDegree(2);
builder.addNode(root);
FIFOQueue queue = new FIFOQueue((int)Math.pow(2, levels+1));
queue.enq(root);
//build a complete binary tree
// number of nodes = 2^(n+1) - 1
int level = 0;
while (level < levels) {
int nnodes = (int)Math.pow(2, level);
for (int i = 0; i < nnodes; i++) {
Node n = (Node)queue.deq();
OptNode ln = (OptNode) builder.buildNode();
if (level < levels-1) ln.setDegree(3);
else ln.setDegree(1);
OptNode rn = (OptNode) builder.buildNode();
if (level < levels-1) rn.setDegree(3);
else rn.setDegree(1);
Edge le = builder.buildEdge(n, ln);
Edge re = builder.buildEdge(n, rn);
builder.addNode(ln);
builder.addNode(rn);
builder.addEdge(le);
builder.addEdge(re);
queue.enq(ln);
queue.enq(rn);
}
level++;
}
return(new Object[]{root});
}
public static Object[] buildPerfectBinaryTree(
OptDirectedGraphBuilder builder, int levels
) {
OptDirectedNode root = (OptDirectedNode)builder.buildNode();
root.setInDegree(0);
root.setOutDegree(2);
builder.addNode(root);
FIFOQueue queue = new FIFOQueue((int)Math.pow(2, levels+1));
queue.enq(root);
//build a complete binary tree
// number of nodes = 2^(n+1) - 1
int level = 0;
while (level < levels) {
int nnodes = (int)Math.pow(2, level);
for (int i = 0; i < nnodes; i++) {
Node n = (Node)queue.deq();
OptDirectedNode ln = (OptDirectedNode) builder.buildNode();
if (level < levels-1) {
ln.setInDegree(1);
ln.setOutDegree(2);
}
else {
ln.setInDegree(1);
ln.setOutDegree(0);
}
OptDirectedNode rn = (OptDirectedNode) builder.buildNode();
if (level < levels-1) {
rn.setInDegree(1);
rn.setOutDegree(2);
}
else {
rn.setInDegree(1);
rn.setOutDegree(0);
}
Edge le = builder.buildEdge(n, ln);
Edge re = builder.buildEdge(n, rn);
builder.addNode(ln);
builder.addNode(rn);
builder.addEdge(le);
builder.addEdge(re);
queue.enq(ln);
queue.enq(rn);
}
level++;
}
return(new Object[]{root});
}
public static Node[] buildCircular(GraphBuilder builder, int nnodes) {
//build a graph with no bifurcations then join the first and last verticies
Node[] ends = buildNoBifurcations(builder, nnodes);
Edge e = builder.buildEdge(ends[1], ends[0]);
builder.addEdge(e);
return(ends);
}
public static Node[] buildCircular(GraphGenerator gen, int nnodes) {
Node[] ends = buildNoBifurcations(gen, nnodes);
gen.add(new Object[]{"0", String.valueOf(nnodes-1)});
return(ends);
}
}