public List<FloorTile> getPath()
{
List<FloorTile> retval = new List<FloorTile>();
if (this.fp == null || this.fp.getStartTile() == null || this.fp.getTargetTile() == null)
return retval;
startPoint = this.fp.getStartTile().Position.X + "_" + this.fp.getStartTile().Position.Y;
targetPoint = this.fp.getTargetTile().Position.X + "_" + this.fp.getTargetTile().Position.Y;
this.messages += "- Start Get Path\n";
//startPoint = txtStartPoint.Text;
//targetPoint = txtTargetPoint.Text;
DijkstraShortestPathAlgorithm<string, Edge<string>> dijkstra = new DijkstraShortestPathAlgorithm<string, Edge<string>>(graph, AlgorithmExtensions.GetIndexer<Edge<string>, double>(edgeCost));
// Attach a Vertex Predecessor Recorder Observer to give us the paths
QuickGraph.Algorithms.Observers.VertexPredecessorRecorderObserver<string, Edge<string>> predecessorObserver = new QuickGraph.Algorithms.Observers.VertexPredecessorRecorderObserver<string, Edge<string>>();
predecessorObserver.Attach(dijkstra);
// attach a distance observer to give us the shortest path distances
VertexDistanceRecorderObserver<string, Edge<string>> distObserver = new VertexDistanceRecorderObserver<string, Edge<string>>(AlgorithmExtensions.GetIndexer<Edge<string>, double>(edgeCost));
distObserver.Attach(dijkstra);
// Run the algorithm with A set to be the source
dijkstra.Compute(startPoint);
this.messages += " Start Point: " + startPoint + ".\n";
this.messages += " Target Point: " + targetPoint + ".\n";
String outString = "";
//outString += distObserver.Distances[targetPoint] + "\n";
IEnumerable<Edge<string>> path;
if (predecessorObserver.TryGetPath(targetPoint, out path))
foreach (var u in path)
outString += u + ";";
string[] outEdges = Regex.Split(outString, ";");
if (outEdges.Length > 0)
{
for (int i = 0; i < outEdges.Length; i++)
{
if (outEdges[i].Length > 0)
{
this.messages += outEdges[i] + "\n";
string[] outPoint = Regex.Split(outEdges[i], "->");
//start points
retval.Add(getTileByIndex(fp, outPoint[0]));
}
}
//add target
retval.Add(getTileByIndex(fp, targetPoint));
}
this.messages += retval.Count.ToString()+ "\n";;
if(retval.Count == 1 && retval[0].Equals(getTileByIndex(fp, targetPoint))){
this.messages += "Can't find path. Start or end point is not walkable or no available walkable tiles" + "\n"; ;
return null;
}
fp.setPath(retval);
//return retval;
return condenseList(retval);
}
public List<FloorTile> getPath()
{
if (this.m_status.position != null)
{
startPoint = this.m_status.position.location.X + "_" + this.m_status.position.location.Y;
m_parent.PostMessage("start: " + startPoint);
}
else
{
startPoint = "4_4";
}
if (this.m_status.endPoint != null)
{
targetPoint = this.m_status.endPoint.X + "_" + this.m_status.endPoint.Y;
m_parent.PostMessage("end: " + targetPoint);
}
else
{
targetPoint = "4_6";
}
//startPoint = txtStartPoint.Text;
//targetPoint = txtTargetPoint.Text;
DijkstraShortestPathAlgorithm<string, Edge<string>> dijkstra = new DijkstraShortestPathAlgorithm<string, Edge<string>>(graph, AlgorithmExtensions.GetIndexer<Edge<string>, double>(edgeCost));
// Attach a Vertex Predecessor Recorder Observer to give us the paths
QuickGraph.Algorithms.Observers.VertexPredecessorRecorderObserver<string, Edge<string>> predecessorObserver = new QuickGraph.Algorithms.Observers.VertexPredecessorRecorderObserver<string, Edge<string>>();
predecessorObserver.Attach(dijkstra);
// attach a distance observer to give us the shortest path distances
VertexDistanceRecorderObserver<string, Edge<string>> distObserver = new VertexDistanceRecorderObserver<string, Edge<string>>(AlgorithmExtensions.GetIndexer<Edge<string>, double>(edgeCost));
distObserver.Attach(dijkstra);
// Run the algorithm with A set to be the source
dijkstra.Compute(startPoint);
String outString = "";
//outString += distObserver.Distances[targetPoint] + "\n";
IEnumerable<Edge<string>> path;
if (predecessorObserver.TryGetPath(targetPoint, out path))
foreach (var u in path)
outString += u + ";";
List<FloorTile> retval = new List<FloorTile>();
string[] outEdges = Regex.Split(outString, ";");
if (outEdges.Length > 0)
{
for (int i = 0; i < outEdges.Length; i++)
{
if (outEdges[i].Length > 0)
{
m_parent.PostMessage(outEdges[i]);
string[] outPoint = Regex.Split(outEdges[i], "->");
//start points
retval.Add(getTileByIndex(fp, outPoint[0]));
}
}
//add target
retval.Add(getTileByIndex(fp, targetPoint));
}
m_parent.PostMessage(retval.Count.ToString());
m_parent.PostMessage(outString);
if(retval.Count == 1 && retval[0].Equals(getTileByIndex(fp, targetPoint))){
m_parent.PostMessage("Can't find path. Start or end point is not walkable or no available walkable tiles");
return null;
}
return condenseList(retval);
}
public void CheckPredecessorDoubleLineGraph()
{
AdjacencyGraph <int, Edge <int> > g = new AdjacencyGraph <int, Edge <int> >(true);
g.AddVertex(1);
g.AddVertex(2);
g.AddVertex(3);
Edge <int> e12 = new Edge <int>(1, 2); g.AddEdge(e12);
Edge <int> e23 = new Edge <int>(2, 3); g.AddEdge(e23);
Edge <int> e13 = new Edge <int>(1, 3); g.AddEdge(e13);
var dij = new DijkstraShortestPathAlgorithm <int, Edge <int> >(g, e => 1);
var vis = new VertexPredecessorRecorderObserver <int, Edge <int> >();
using (vis.Attach(dij))
dij.Compute(1);
IEnumerable <Edge <int> > path;
Assert.IsTrue(vis.TryGetPath(2, out path));
var col = path.ToList();
Assert.AreEqual(1, col.Count);
Assert.AreEqual(e12, col[0]);
Assert.IsTrue(vis.TryGetPath(3, out path));
col = path.ToList();
Assert.AreEqual(1, col.Count);
Assert.AreEqual(e13, col[0]);
}
public void Compute()
{
var g = new AdjacencyGraph <char, Edge <char> >();
var distances = new Dictionary <Edge <char>, double>();
g.AddVertexRange("ABCDE");
AddEdge(g, distances, 'A', 'C', 1);
AddEdge(g, distances, 'B', 'B', 2);
AddEdge(g, distances, 'B', 'D', 1);
AddEdge(g, distances, 'B', 'E', 2);
AddEdge(g, distances, 'C', 'B', 7);
AddEdge(g, distances, 'C', 'D', 3);
AddEdge(g, distances, 'D', 'E', 1);
AddEdge(g, distances, 'E', 'A', 1);
AddEdge(g, distances, 'E', 'B', 1);
var dijkstra = new DijkstraShortestPathAlgorithm <char, Edge <char> >(g, AlgorithmExtensions.GetIndexer(distances));
var predecessors = new VertexPredecessorRecorderObserver <char, Edge <char> >();
using (predecessors.Attach(dijkstra))
dijkstra.Compute('A');
Assert.AreEqual(0, dijkstra.Distances['A']);
Assert.AreEqual(6, dijkstra.Distances['B']);
Assert.AreEqual(1, dijkstra.Distances['C']);
Assert.AreEqual(4, dijkstra.Distances['D']);
Assert.AreEqual(5, dijkstra.Distances['E']);
}
private static void Verify <TVertex, TEdge>(
DijkstraShortestPathAlgorithm <TVertex, TEdge> algo,
VertexPredecessorRecorderObserver <TVertex, TEdge> predecessors
)
where TEdge : IEdge <TVertex>
{
// let's verify the result
foreach (var v in algo.VisitedGraph.Vertices)
{
TEdge predecessor;
if (!predecessors.VertexPredecessors.TryGetValue(v, out predecessor))
{
continue;
}
if (predecessor.Source.Equals(v))
{
continue;
}
double vd, vp;
bool found;
Assert.AreEqual(
found = algo.TryGetDistance(v, out vd),
algo.TryGetDistance(predecessor.Source, out vp)
);
}
}
public void CheckPredecessorLineGraph()
{
AdjacencyGraph <int, Edge <int> > g = new AdjacencyGraph <int, Edge <int> >(true);
g.AddVertex(1);
g.AddVertex(2);
g.AddVertex(3);
Edge <int> e12 = new Edge <int>(1, 2); g.AddEdge(e12);
Edge <int> e23 = new Edge <int>(2, 3); g.AddEdge(e23);
Dictionary <Edge <int>, double> weights =
DijkstraShortestPathAlgorithm <int, Edge <int> > .UnaryWeightsFromEdgeList(g);
DijkstraShortestPathAlgorithm <int, Edge <int> > dij = new DijkstraShortestPathAlgorithm <int, Edge <int> >(g, weights);
VertexPredecessorRecorderObserver <int, Edge <int> > vis = new VertexPredecessorRecorderObserver <int, Edge <int> >();
vis.Attach(dij);
dij.Compute(1);
IList <Edge <int> > col = vis.Path(2);
Assert.AreEqual(1, col.Count);
Assert.AreEqual(e12, col[0]);
col = vis.Path(3);
Assert.AreEqual(2, col.Count);
Assert.AreEqual(e12, col[0]);
Assert.AreEqual(e23, col[1]);
}
public void CheckPredecessorLineGraph()
{
AdjacencyGraph g = new AdjacencyGraph(true);
IVertex v1 = g.AddVertex();
IVertex v2 = g.AddVertex();
IVertex v3 = g.AddVertex();
IEdge e12 = g.AddEdge(v1,v2);
IEdge e23 = g.AddEdge(v2,v3);
EdgeDoubleDictionary weights = DijkstraShortestPathAlgorithm.UnaryWeightsFromEdgeList(g);
DijkstraShortestPathAlgorithm dij = new DijkstraShortestPathAlgorithm(g,weights);
PredecessorRecorderVisitor vis = new PredecessorRecorderVisitor();
dij.RegisterPredecessorRecorderHandlers(vis);
dij.Compute(v1);
EdgeCollection col = vis.Path(v2);
Assert.AreEqual(1,col.Count);
Assert.AreEqual(e12,col[0]);
col = vis.Path(v3);
Assert.AreEqual(2,col.Count);
Assert.AreEqual(e12,col[0]);
Assert.AreEqual(e23,col[1]);
}
public void CheckPredecessorLineGraph()
{
AdjacencyGraph<int, Edge<int>> g = new AdjacencyGraph<int, Edge<int>>(true);
g.AddVertex(1);
g.AddVertex(2);
g.AddVertex(3);
Edge<int> e12 = new Edge<int>(1, 2); g.AddEdge(e12);
Edge<int> e23 = new Edge<int>(2, 3); g.AddEdge(e23);
var dij = new DijkstraShortestPathAlgorithm<int, Edge<int>>(g, e => 1);
var vis = new VertexPredecessorRecorderObserver<int, Edge<int>>();
using(vis.Attach(dij))
dij.Compute(1);
IEnumerable<Edge<int>> path;
Assert.IsTrue(vis.TryGetPath(2, out path));
var col = path.ToList();
Assert.AreEqual(1, col.Count);
Assert.AreEqual(e12, col[0]);
Assert.IsTrue(vis.TryGetPath(3, out path));
col = path.ToList();
Assert.AreEqual(2, col.Count);
Assert.AreEqual(e12, col[0]);
Assert.AreEqual(e23, col[1]);
}
public void AttachDistanceRecorderVisitor()
{
AdjacencyGraph g = new AdjacencyGraph(true);
EdgeDoubleDictionary weights = DijkstraShortestPathAlgorithm.UnaryWeightsFromEdgeList(g);
DijkstraShortestPathAlgorithm dij = new DijkstraShortestPathAlgorithm(g,weights);
DistanceRecorderVisitor vis = new DistanceRecorderVisitor();
dij.RegisterDistanceRecorderHandlers(vis);
}
public void CreateGraph()
{
graph = new AdjacencyGraph <string, Edge <string> >(true);
// Add some vertices to the graph
graph.AddVertex("A");
graph.AddVertex("B");
graph.AddVertex("D");
graph.AddVertex("C");
graph.AddVertex("E");
// Create the edges
var a_b = new Edge <string>("A", "B");
var a_c = new Edge <string>("A", "C");
var b_e = new Edge <string>("B", "E");
var c_d = new Edge <string>("C", "D");
var d_e = new Edge <string>("D", "E");
// Add edges to the graph
graph.AddEdge(a_b);
graph.AddEdge(a_c);
graph.AddEdge(c_d);
graph.AddEdge(d_e);
graph.AddEdge(b_e);
// Define some weights to the edges
var weight = new Dictionary <Edge <string>, double>(graph.EdgeCount);
weight.Add(a_b, 30);
weight.Add(a_c, 30);
weight.Add(b_e, 60);
weight.Add(c_d, 40);
weight.Add(d_e, 4);
algo = new DijkstraShortestPathAlgorithm <string, Edge <string> >(graph, weight);
// Attach a Vertex Predecessor Recorder Observer to give us the paths
predecessorObserver = new VertexPredecessorRecorderObserver <string, Edge <string> >();
using (ObserverScope.Create <IVertexPredecessorRecorderAlgorithm <string, Edge <string> > >(algo, predecessorObserver))
{
// Run the algorithm with A set to be the source
algo.Compute("A");
}
path = new List <string>();
PopulatePath("E");
Assert.IsTrue(algo.Distances["E"] == 74);
path.Reverse();
Console.WriteLine(String.Join(" -> ", path.ToArray()));
}
private void Search(IVertexAndEdgeListGraph<string,Edge<string>> g, string root)
{
DijkstraShortestPathAlgorithm<string,Edge<string>> algo = new DijkstraShortestPathAlgorithm<string,Edge<string>>(g,
DijkstraShortestPathAlgorithm<string,Edge<string>>.UnaryWeightsFromEdgeList(g)
);
VertexPredecessorRecorderObserver<string,Edge<string>> predecessors = new VertexPredecessorRecorderObserver<string,Edge<string>>();
predecessors.Attach(algo);
algo.Compute(root);
Verify(algo, predecessors);
}
private void Search(IVertexAndEdgeListGraph <string, Edge <string> > g, string root)
{
DijkstraShortestPathAlgorithm <string, Edge <string> > algo = new DijkstraShortestPathAlgorithm <string, Edge <string> >(g,
DijkstraShortestPathAlgorithm <string, Edge <string> > .UnaryWeightsFromEdgeList(g)
);
VertexPredecessorRecorderObserver <string, Edge <string> > predecessors = new VertexPredecessorRecorderObserver <string, Edge <string> >();
predecessors.Attach(algo);
algo.Compute(root);
Verify(algo, predecessors);
}
public void Compute(IVertexAndEdgeListGraph<string, Edge<string>> g)
{
if (g.VertexCount == 0) return;
var rnd = new Random();
var distances = new Dictionary<Edge<string>, double>();
foreach(var edge in g.Edges)
distances.Add(edge, rnd.Next(100));
var bfs = new DijkstraShortestPathAlgorithm<string, Edge<string>>(g, distances);
bfs.Compute(TraversalHelper.GetFirstVertex(g));
}
private static void Verify(DijkstraShortestPathAlgorithm<string, Edge<string>> algo, VertexPredecessorRecorderObserver<string, Edge<string>> predecessors)
{
// let's verify the result
foreach (string v in algo.VisitedGraph.Vertices)
{
Edge<string> predecessor;
if (!predecessors.VertexPredecessors.TryGetValue(v, out predecessor))
continue;
if (predecessor.Source == v)
continue;
Assert.AreEqual(
algo.Distances[v], algo.Distances[predecessor.Source] + 1
);
}
}
public void CreateGraph()
{
graph = new AdjacencyGraph <string, Edge <string> >(true);
// Add some vertices to the graph
graph.AddVertex("A");
graph.AddVertex("B");
graph.AddVertex("D");
graph.AddVertex("C");
graph.AddVertex("E");
// Create the edges
var a_b = new Edge <string>("A", "B");
var a_c = new Edge <string>("A", "C");
var b_e = new Edge <string>("B", "E");
var c_d = new Edge <string>("C", "D");
var d_e = new Edge <string>("D", "E");
// Add edges to the graph
graph.AddEdge(a_b);
graph.AddEdge(a_c);
graph.AddEdge(c_d);
graph.AddEdge(d_e);
graph.AddEdge(b_e);
// Define some weights to the edges
var weight = new Dictionary <Edge <string>, double>(graph.EdgeCount);
weight.Add(a_b, 30);
weight.Add(a_c, 30);
weight.Add(b_e, 60);
weight.Add(c_d, 40);
weight.Add(d_e, 4);
algo = new DijkstraShortestPathAlgorithm <string, Edge <string> >(graph, e => weight[e]);
// Attach a Vertex Predecessor Recorder Observer to give us the paths
predecessorObserver = new VertexPredecessorRecorderObserver <string, Edge <string> >();
using (predecessorObserver.Attach(algo))
// Run the algorithm with A set to be the source
algo.Compute("A");
Assert.IsTrue(algo.Distances["E"] == 74);
}
public void RunOnLineGraph()
{
AdjacencyGraph<int, Edge<int>> g = new AdjacencyGraph<int, Edge<int>>(true);
g.AddVertex(1);
g.AddVertex(2);
g.AddVertex(3);
g.AddEdge(new Edge<int>(1,2));
g.AddEdge(new Edge<int>(2,3));
var dij = new DijkstraShortestPathAlgorithm<int, Edge<int>>(g, e => 1);
dij.Compute(1);
Assert.AreEqual<double>(0, dij.Distances[1]);
Assert.AreEqual<double>(1, dij.Distances[2]);
Assert.AreEqual<double>(2, dij.Distances[3]);
}
public void RunOnDoubleLineGraph()
{
AdjacencyGraph<int, Edge<int>> g = new AdjacencyGraph<int, Edge<int>>(true);
g.AddVertex(1);
g.AddVertex(2);
g.AddVertex(3);
Edge<int> e12 = new Edge<int>(1, 2); g.AddEdge(e12);
Edge<int> e23 = new Edge<int>(2, 3); g.AddEdge(e23);
Edge<int> e13 = new Edge<int>(1, 3); g.AddEdge(e13);
var dij = new DijkstraShortestPathAlgorithm<int, Edge<int>>(g, e => 1);
dij.Compute(1);
Assert.AreEqual(0.0, dij.Distances[1]);
Assert.AreEqual(1.0, dij.Distances[2]);
Assert.AreEqual(1.0, dij.Distances[3]);
}
public void Compute(IVertexAndEdgeListGraph <string, Edge <string> > g)
{
if (g.VertexCount == 0)
{
return;
}
var rnd = new Random();
var distances = new Dictionary <Edge <string>, double>();
foreach (var edge in g.Edges)
{
distances.Add(edge, rnd.Next(100));
}
var bfs = new DijkstraShortestPathAlgorithm <string, Edge <string> >(g, distances);
bfs.Compute(TraversalHelper.GetFirstVertex(g));
}
public void RunOnLineGraph()
{
AdjacencyGraph g = new AdjacencyGraph(true);
IVertex v1 = g.AddVertex();
IVertex v2 = g.AddVertex();
IVertex v3 = g.AddVertex();
IEdge e12 = g.AddEdge(v1,v2);
IEdge e23 = g.AddEdge(v2,v3);
EdgeDoubleDictionary weights = DijkstraShortestPathAlgorithm.UnaryWeightsFromEdgeList(g);
DijkstraShortestPathAlgorithm dij = new DijkstraShortestPathAlgorithm(g,weights);
dij.Compute(v1);
Assert.AreEqual(0, dij.Distances[v1]);
Assert.AreEqual(1, dij.Distances[v2]);
Assert.AreEqual(2, dij.Distances[v3]);
}
public void RunOnLineGraph()
{
AdjacencyGraph<int, Edge<int>> g = new AdjacencyGraph<int, Edge<int>>(true);
g.AddVertex(1);
g.AddVertex(2);
g.AddVertex(3);
g.AddEdge(new Edge<int>(1,2));
g.AddEdge(new Edge<int>(2,3));
Dictionary<Edge<int>,double> weights =
DijkstraShortestPathAlgorithm<int,Edge<int>>.UnaryWeightsFromEdgeList(g);
DijkstraShortestPathAlgorithm<int, Edge<int>> dij = new DijkstraShortestPathAlgorithm<int, Edge<int>>(g, weights);
dij.Compute(1);
Assert.AreEqual<double>(0, dij.Distances[1]);
Assert.AreEqual<double>(1, dij.Distances[2]);
Assert.AreEqual<double>(2, dij.Distances[3]);
}
private static void Verify(DijkstraShortestPathAlgorithm <string, Edge <string> > algo, VertexPredecessorRecorderObserver <string, Edge <string> > predecessors)
{
// let's verify the result
foreach (string v in algo.VisitedGraph.Vertices)
{
Edge <string> predecessor;
if (!predecessors.VertexPredecessors.TryGetValue(v, out predecessor))
{
continue;
}
if (predecessor.Source == v)
{
continue;
}
Assert.AreEqual(
algo.Distances[v], algo.Distances[predecessor.Source] + 1
);
}
}
public void RunOnLineGraph()
{
AdjacencyGraph <int, Edge <int> > g = new AdjacencyGraph <int, Edge <int> >(true);
g.AddVertex(1);
g.AddVertex(2);
g.AddVertex(3);
g.AddEdge(new Edge <int>(1, 2));
g.AddEdge(new Edge <int>(2, 3));
var dij = new DijkstraShortestPathAlgorithm <int, Edge <int> >(g, e => 1);
dij.Compute(1);
Assert.AreEqual <double>(0, dij.Distances[1]);
Assert.AreEqual <double>(1, dij.Distances[2]);
Assert.AreEqual <double>(2, dij.Distances[3]);
}
public void RunOnDoubleLineGraph()
{
AdjacencyGraph <int, Edge <int> > g = new AdjacencyGraph <int, Edge <int> >(true);
g.AddVertex(1);
g.AddVertex(2);
g.AddVertex(3);
Edge <int> e12 = new Edge <int>(1, 2); g.AddEdge(e12);
Edge <int> e23 = new Edge <int>(2, 3); g.AddEdge(e23);
Edge <int> e13 = new Edge <int>(1, 3); g.AddEdge(e13);
var dij = new DijkstraShortestPathAlgorithm <int, Edge <int> >(g, e => 1);
dij.Compute(1);
Assert.AreEqual(0.0, dij.Distances[1]);
Assert.AreEqual(1.0, dij.Distances[2]);
Assert.AreEqual(1.0, dij.Distances[3]);
}
private void Dijkstra <TVertex, TEdge>(IVertexAndEdgeListGraph <TVertex, TEdge> g, TVertex root)
where TEdge : IEdge <TVertex>
{
var distances = new Dictionary <TEdge, double>(g.EdgeCount);
foreach (var e in g.Edges)
{
distances[e] = g.OutDegree(e.Source) + 1;
}
var algo = new DijkstraShortestPathAlgorithm <TVertex, TEdge>(
g,
e => distances[e]
);
var predecessors = new VertexPredecessorRecorderObserver <TVertex, TEdge>();
using (predecessors.Attach(algo))
algo.Compute(root);
Verify(algo, predecessors);
}
public void RunOnLineGraph()
{
AdjacencyGraph <int, Edge <int> > g = new AdjacencyGraph <int, Edge <int> >(true);
g.AddVertex(1);
g.AddVertex(2);
g.AddVertex(3);
g.AddEdge(new Edge <int>(1, 2));
g.AddEdge(new Edge <int>(2, 3));
Dictionary <Edge <int>, double> weights =
DijkstraShortestPathAlgorithm <int, Edge <int> > .UnaryWeightsFromEdgeList(g);
DijkstraShortestPathAlgorithm <int, Edge <int> > dij = new DijkstraShortestPathAlgorithm <int, Edge <int> >(g, weights);
dij.Compute(1);
Assert.AreEqual <double>(0, dij.Distances[1]);
Assert.AreEqual <double>(1, dij.Distances[2]);
Assert.AreEqual <double>(2, dij.Distances[3]);
}
internal ILineString PerformShortestPathAnalysis(IPoint source, IPoint destination,bool usesCondensedGraph)
{
// We keep a copy so we can terminate the search early.
_theDestination = destination;
// This is an instrance of the shortest path algortihm.
_dijkstra = new DijkstraShortestPathAlgorithm<Coordinate, Edge<Coordinate>>(_graph, AlgorithmExtensions.GetIndexer(_edgeCost));
// Quick Graph uses 'observers' to record the distance traveled and the path travelled througth,
var distObserver = new VertexDistanceRecorderObserver<Coordinate, Edge<Coordinate>>(AlgorithmExtensions.GetIndexer(_edgeCost));
var predecessorObserver = new VertexPredecessorRecorderObserver<Coordinate, Edge<Coordinate>>();
distObserver.Attach(_dijkstra);
predecessorObserver.Attach(_dijkstra);
// Having this present means that when we finally reach the target node
// the dijkstra algortihm can quit without scanning other nodes in the graph, leading to
// performance increases.
_dijkstra.FinishVertex += dijkstra_FinishVertex;
// This is where the shortest path is calculated.
var sw = new System.Diagnostics.Stopwatch();
sw.Start();
_dijkstra.Compute(source.Coordinate);
sw.Stop();
System.Diagnostics.Debug.WriteLine("Dijsktra Took: " + sw.ElapsedMilliseconds);
// get the cost of the path. If one is found then d (=distance) should be greater than zero so we get the edges making up
// the path.
double d = AlgorithmExtensions.ComputePredecessorCost(predecessorObserver.VertexPredecessors, _edgeCost, destination.Coordinate);
System.Diagnostics.Debug.WriteLine(d);
if (d > 0)
{
IEnumerable<Edge<Coordinate>> edgesInShortestPath;
if (predecessorObserver.TryGetPath(destination.Coordinate, out edgesInShortestPath))
{
var theCompleteShortestPath = new List<Coordinate>();
// We need to use a different approach when using the condensed graph.
if (usesCondensedGraph)
{
foreach (var edgeInShortPath in edgesInShortestPath)
{
var ls = GetLineStringInformation(edgeInShortPath);
if (ls != null)
{
// We need to get each of the nodes that makes up the lines.
// we need to add each of them on one list.
var count = ls.Coordinates.Length;
for (var i = 0; i < count; i++)
theCompleteShortestPath.Add(ls.Coordinates[i]);
} // End Of If
} // Loop Around Each Edge In The Shortest Path
} // End of If
else
{
foreach (var edgeInShortPath in edgesInShortestPath)
{
theCompleteShortestPath.Add(edgeInShortPath.Source);
theCompleteShortestPath.Add(edgeInShortPath.Target);
}
} // End Of Else
var theShortestPath = _geomFactory.CreateLineString(theCompleteShortestPath.ToArray());
return theShortestPath;
} // There Was A Shortest Path
// Return null.
// ToDo: Need to improve this bit so it at least indicates if the SP didnt get a path/
return null;
}
return null;
}
public void UnaryWeights()
{
AdjacencyGraph <int, Edge <int> > g = new AdjacencyGraph <int, Edge <int> >(true);
Dictionary <Edge <int>, double> weights =
DijkstraShortestPathAlgorithm <int, Edge <int> > .UnaryWeightsFromEdgeList(g);
}
public void CreateAlgorithmWithNullGraph()
{
DijkstraShortestPathAlgorithm<int,Edge<int>> dij = new
DijkstraShortestPathAlgorithm<int, Edge<int>>(null, null);
}
public void CreateGraph()
{
graph = new AdjacencyGraph<string, Edge<string>>(true);
// Add some vertices to the graph
graph.AddVertex("A");
graph.AddVertex("B");
graph.AddVertex("D");
graph.AddVertex("C");
graph.AddVertex("E");
// Create the edges
var a_b = new Edge<string>("A", "B");
var a_c = new Edge<string>("A", "C");
var b_e = new Edge<string>("B", "E");
var c_d = new Edge<string>("C", "D");
var d_e = new Edge<string>("D", "E");
// Add edges to the graph
graph.AddEdge(a_b);
graph.AddEdge(a_c);
graph.AddEdge(c_d);
graph.AddEdge(d_e);
graph.AddEdge(b_e);
// Define some weights to the edges
var weight = new Dictionary<Edge<string>, double>(graph.EdgeCount);
weight.Add(a_b, 30);
weight.Add(a_c, 30);
weight.Add(b_e, 60);
weight.Add(c_d, 40);
weight.Add(d_e, 4);
algo = new DijkstraShortestPathAlgorithm<string, Edge<string>>(graph, weight);
// Attach a Vertex Predecessor Recorder Observer to give us the paths
predecessorObserver = new VertexPredecessorRecorderObserver<string, Edge<string>>();
using (ObserverScope.Create<IVertexPredecessorRecorderAlgorithm<string, Edge<string>>>(algo, predecessorObserver))
{
// Run the algorithm with A set to be the source
algo.Compute("A");
}
path = new List<string>();
PopulatePath("E");
Assert.IsTrue(algo.Distances["E"] == 74);
path.Reverse();
Console.WriteLine(String.Join(" -> ", path.ToArray()));
}
/// <summary>
/// Carries out the shortest path between the two nodes
/// ids passed as variables and returns an <see cref="ILineString" />
/// giveing the shortest path.
/// </summary>
/// <param name="source">The source node</param>
/// <param name="destination">The destination node</param>
/// <returns>A line string geometric shape of the path</returns>
public ILineString Perform(ICoordinate source, ICoordinate destination)
{
if (!graph.ContainsVertex(source))
throw new ArgumentException("key not found in the graph", "source");
if (!graph.ContainsVertex(destination))
throw new ArgumentException("key not found in the graph", "destination");
// Build algorithm
DijkstraShortestPathAlgorithm<ICoordinate, IEdge<ICoordinate>> dijkstra =
new DijkstraShortestPathAlgorithm<ICoordinate, IEdge<ICoordinate>>(graph, consts);
// Attach a Distance observer to give us the distances between edges
VertexDistanceRecorderObserver<ICoordinate, IEdge<ICoordinate>> distanceObserver =
new VertexDistanceRecorderObserver<ICoordinate, IEdge<ICoordinate>>();
distanceObserver.Attach(dijkstra);
// Attach a Vertex Predecessor Recorder Observer to give us the paths
VertexPredecessorRecorderObserver<ICoordinate, IEdge<ICoordinate>> predecessorObserver =
new VertexPredecessorRecorderObserver<ICoordinate, IEdge<ICoordinate>>();
predecessorObserver.Attach(dijkstra);
// Run the algorithm with A set to be the source
dijkstra.Compute(source);
// Get the path computed to the destination.
IList<IEdge<ICoordinate>> path = predecessorObserver.Path(destination);
// Then we need to turn that into a geomery.
if (path.Count > 1)
return buildString(path);
// if the count is greater than one then a
// path could not be found, so we return null
return null;
}
public void BuildGraphAndSearchShortestPathUsingGeometryUnion()
{
IGeometry edges = a.Union(b).Union(c).Union(d).Union(e);
Assert.IsNotNull(edges);
Assert.IsTrue(edges.GetType() == typeof(MultiLineString));
Assert.Greater(edges.NumGeometries, 0);
foreach (IGeometry edge in ((GeometryCollection) edges).Geometries)
{
Assert.IsNotNull(edge);
Assert.IsTrue(edge.GetType() == typeof(LineString));
Debug.WriteLine(edge);
}
// Build graph
IDictionary<IEdge<IGeometry>, double> consts = new Dictionary<IEdge<IGeometry>, double>(edges.NumGeometries);
AdjacencyGraph<IGeometry, IEdge<IGeometry>> graph = new AdjacencyGraph<IGeometry, IEdge<IGeometry>>(true);
foreach (ILineString str in ((GeometryCollection) edges).Geometries)
{
// Add vertex 1
IGeometry vertex1 = str.StartPoint;
Assert.IsNotNull(vertex1);
if (!graph.ContainsVertex(vertex1))
{
Debug.WriteLine(String.Format("Adding vertex {0} to the list", vertex1));
graph.AddVertex(vertex1);
}
else Debug.WriteLine(String.Format("Vertex {0} already present", vertex1));
// Add vertex 2
IGeometry vertex2 = str.EndPoint;
Assert.IsNotNull(vertex2);
if (!graph.ContainsVertex(vertex2))
{
Debug.WriteLine(String.Format("Adding vertex {0} to the list", vertex2));
graph.AddVertex(vertex2);
}
else Debug.WriteLine(String.Format("Vertex {0} already present", vertex2));
// Compute weight
double weight = weightComputer(str);
Assert.Greater(weight, 0.0);
// Add edge for 1 => 2
IEdge<IGeometry> edge1 = new Edge<IGeometry>(vertex1, vertex2);
Assert.IsNotNull(edge1);
graph.AddEdge(edge1);
consts.Add(edge1, weight);
// Add edge for 2 => 1
IEdge<IGeometry> edge2 = new Edge<IGeometry>(vertex2, vertex1);
Assert.IsNotNull(edge2);
graph.AddEdge(edge2);
consts.Add(edge2, weight);
}
// Perform DijkstraShortestPathAlgorithm
DijkstraShortestPathAlgorithm<IGeometry, IEdge<IGeometry>> dijkstra =
new DijkstraShortestPathAlgorithm<IGeometry, IEdge<IGeometry>>(graph, consts);
// attach a distance observer to give us the shortest path distances
VertexDistanceRecorderObserver<IGeometry, IEdge<IGeometry>> distObserver =
new VertexDistanceRecorderObserver<IGeometry, IEdge<IGeometry>>();
distObserver.Attach(dijkstra);
// Attach a Vertex Predecessor Recorder Observer to give us the paths
VertexPredecessorRecorderObserver<IGeometry, IEdge<IGeometry>> predecessorObserver =
new VertexPredecessorRecorderObserver<IGeometry, IEdge<IGeometry>>();
predecessorObserver.Attach(dijkstra);
// Run the algorithm
Debug.WriteLine(String.Format("Starting algorithm from root vertex {0}", start));
dijkstra.Compute(start);
foreach (KeyValuePair<IGeometry, int> kvp in distObserver.Distances)
Debug.WriteLine(String.Format("Distance from root to node {0} is {1}",
kvp.Key, kvp.Value));
foreach (KeyValuePair<IGeometry, IEdge<IGeometry>> kvp in predecessorObserver.VertexPredecessors)
Debug.WriteLine(String.Format(
"If you want to get to {0} you have to enter through the IN edge {1}", kvp.Key, kvp.Value));
Check(graph, consts, predecessorObserver);
// Detach the observers
distObserver.Detach(dijkstra);
predecessorObserver.Detach(dijkstra);
}
public void BuildGraphFromMinimalGraphShapefile()
{
string path = "minimalgraph.shp";
int count = 15;
Assert.IsTrue(File.Exists(path));
ShapefileReader reader = new ShapefileReader(path);
IGeometryCollection edges = reader.ReadAll();
Assert.IsNotNull(edges);
Assert.IsInstanceOfType(typeof(GeometryCollection), edges);
Assert.AreEqual(count, edges.NumGeometries);
ILineString startls = null;
// Build graph
Dictionary<IEdge<IGeometry>, double> consts = new Dictionary<IEdge<IGeometry>, double>(edges.NumGeometries);
AdjacencyGraph<IGeometry, IEdge<IGeometry>> graph = new AdjacencyGraph<IGeometry, IEdge<IGeometry>>(true);
foreach (IMultiLineString mlstr in edges.Geometries)
{
Assert.AreEqual(1, mlstr.NumGeometries);
ILineString str = (ILineString) mlstr.GetGeometryN(0);
if (startls == null)
startls = str;
// Add vertex 1
IGeometry vertex1 = str.StartPoint;
Assert.IsNotNull(vertex1);
if (!graph.ContainsVertex(vertex1))
{
Debug.WriteLine(String.Format("Adding vertex {0} to the list", vertex1));
graph.AddVertex(vertex1);
}
else Debug.WriteLine(String.Format("Vertex {0} already present", vertex1));
// Add vertex 2
IGeometry vertex2 = str.EndPoint;
Assert.IsNotNull(vertex2);
if (!graph.ContainsVertex(vertex2))
{
Debug.WriteLine(String.Format("Adding vertex {0} to the list", vertex2));
graph.AddVertex(vertex2);
}
else Debug.WriteLine(String.Format("Vertex {0} already present", vertex2));
// Compute weight
double weight = weightComputer(str);
Assert.Greater(weight, 0.0);
// Add edge 1 => 2
IEdge<IGeometry> edge1 = new Edge<IGeometry>(vertex1, vertex2);
Assert.IsNotNull(edge1);
graph.AddEdge(edge1);
consts.Add(edge1, weight);
// Add edge 2 => 1
IEdge<IGeometry> edge2 = new Edge<IGeometry>(vertex2, vertex1);
Assert.IsNotNull(edge2);
graph.AddEdge(edge2);
consts.Add(edge2, weight);
}
// Perform DijkstraShortestPathAlgorithm
DijkstraShortestPathAlgorithm<IGeometry, IEdge<IGeometry>> dijkstra =
new DijkstraShortestPathAlgorithm<IGeometry, IEdge<IGeometry>>(graph, consts);
// attach a distance observer to give us the shortest path distances
VertexDistanceRecorderObserver<IGeometry, IEdge<IGeometry>> distObserver =
new VertexDistanceRecorderObserver<IGeometry, IEdge<IGeometry>>();
distObserver.Attach(dijkstra);
// Attach a Vertex Predecessor Recorder Observer to give us the paths
VertexPredecessorRecorderObserver<IGeometry, IEdge<IGeometry>> predecessorObserver =
new VertexPredecessorRecorderObserver<IGeometry, IEdge<IGeometry>>();
predecessorObserver.Attach(dijkstra);
// Run the algorithm
Assert.IsNotNull(startls);
IGeometry startPoint = startls.StartPoint;
Debug.WriteLine(String.Format("Starting algorithm from root vertex {0}", startPoint));
dijkstra.Compute(startPoint);
foreach (KeyValuePair<IGeometry, int> kvp in distObserver.Distances)
Debug.WriteLine(String.Format("Distance from root to node {0} is {1}",
kvp.Key, kvp.Value));
foreach (KeyValuePair<IGeometry, IEdge<IGeometry>> kvp in predecessorObserver.VertexPredecessors)
Debug.WriteLine(String.Format(
"If you want to get to {0} you have to enter through the IN edge {1}", kvp.Key, kvp.Value));
Check(graph, consts, predecessorObserver);
// Detach the observers
distObserver.Detach(dijkstra);
predecessorObserver.Detach(dijkstra);
}
public void CreateAlgorithmWithNullWeights()
{
AdjacencyGraph <int, Edge <int> > g = new AdjacencyGraph <int, Edge <int> >(true);
DijkstraShortestPathAlgorithm <int, Edge <int> > dij =
new DijkstraShortestPathAlgorithm <int, Edge <int> >(g, null);
}
static void PrepareGitHubExample()
{
AdjacencyGraph<string, Edge<string>> graph = new AdjacencyGraph<string, Edge<string>>(true);
// Add some vertices to the graph
graph.AddVertex("A");
graph.AddVertex("B");
graph.AddVertex("C");
graph.AddVertex("D");
graph.AddVertex("E");
graph.AddVertex("F");
graph.AddVertex("G");
graph.AddVertex("H");
graph.AddVertex("I");
graph.AddVertex("J");
// Create the edges
Edge<string> a_b = new Edge<string>("A", "B");
Edge<string> a_d = new Edge<string>("A", "D");
Edge<string> b_a = new Edge<string>("B", "A");
Edge<string> b_c = new Edge<string>("B", "C");
Edge<string> b_e = new Edge<string>("B", "E");
Edge<string> c_b = new Edge<string>("C", "B");
Edge<string> c_f = new Edge<string>("C", "F");
Edge<string> c_j = new Edge<string>("C", "J");
Edge<string> d_e = new Edge<string>("D", "E");
Edge<string> d_g = new Edge<string>("D", "G");
Edge<string> e_d = new Edge<string>("E", "D");
Edge<string> e_f = new Edge<string>("E", "F");
Edge<string> e_h = new Edge<string>("E", "H");
Edge<string> f_i = new Edge<string>("F", "I");
Edge<string> f_j = new Edge<string>("F", "J");
Edge<string> g_d = new Edge<string>("G", "D");
Edge<string> g_h = new Edge<string>("G", "H");
Edge<string> h_g = new Edge<string>("H", "G");
Edge<string> h_i = new Edge<string>("H", "I");
Edge<string> i_f = new Edge<string>("I", "F");
Edge<string> i_j = new Edge<string>("I", "J");
Edge<string> i_h = new Edge<string>("I", "H");
Edge<string> j_f = new Edge<string>("J", "F");
// Add the edges
graph.AddEdge(a_b);
graph.AddEdge(a_d);
graph.AddEdge(b_a);
graph.AddEdge(b_c);
graph.AddEdge(b_e);
graph.AddEdge(c_b);
graph.AddEdge(c_f);
graph.AddEdge(c_j);
graph.AddEdge(d_e);
graph.AddEdge(d_g);
graph.AddEdge(e_d);
graph.AddEdge(e_f);
graph.AddEdge(e_h);
graph.AddEdge(f_i);
graph.AddEdge(f_j);
graph.AddEdge(g_d);
graph.AddEdge(g_h);
graph.AddEdge(h_g);
graph.AddEdge(h_i);
graph.AddEdge(i_f);
graph.AddEdge(i_h);
graph.AddEdge(i_j);
graph.AddEdge(j_f);
// Define some weights to the edges
Dictionary<Edge<string>, double> edgeCost = new Dictionary<Edge<string>, double>(graph.EdgeCount);
edgeCost.Add(a_b, 4);
edgeCost.Add(a_d, 1);
edgeCost.Add(b_a, 74);
edgeCost.Add(b_c, 2);
edgeCost.Add(b_e, 12);
edgeCost.Add(c_b, 12);
edgeCost.Add(c_f, 74);
edgeCost.Add(c_j, 12);
edgeCost.Add(d_e, 32);
edgeCost.Add(d_g, 22);
edgeCost.Add(e_d, 66);
edgeCost.Add(e_f, 76);
edgeCost.Add(e_h, 33);
edgeCost.Add(f_i, 11);
edgeCost.Add(f_j, 21);
edgeCost.Add(g_d, 12);
edgeCost.Add(g_h, 10);
edgeCost.Add(h_g, 2);
edgeCost.Add(h_i, 72);
edgeCost.Add(i_f, 31);
edgeCost.Add(i_h, 18);
edgeCost.Add(i_j, 7);
edgeCost.Add(j_f, 8);
Func<Edge<string>, double> edgeCostFunction = e => edgeCost[e]; // constant cost
Func<Edge<string>, double> distObserverFunction = e => 1;
// We want to use Dijkstra on this graph
DijkstraShortestPathAlgorithm<string, Edge<string>> dijkstra = new DijkstraShortestPathAlgorithm<string, Edge<string>>(graph, edgeCostFunction);
// attach a distance observer to give us the shortest path distances
VertexDistanceRecorderObserver<string, Edge<string>> distObserver = new VertexDistanceRecorderObserver<string, Edge<string>>(distObserverFunction);
distObserver.Attach(dijkstra);
// Attach a Vertex Predecessor Recorder Observer to give us the paths
VertexPredecessorRecorderObserver<string, Edge<string>> predecessorObserver = new VertexPredecessorRecorderObserver<string, Edge<string>>();
predecessorObserver.Attach(dijkstra);
// Run the algorithm with A set to be the source
dijkstra.Compute("A");
foreach (KeyValuePair<string, double> kvp in distObserver.Distances)
Console.WriteLine("Distance from root to node {0} is {1}", kvp.Key, kvp.Value);
foreach (KeyValuePair<string, Edge<string>> kvp in predecessorObserver.VertexPredecessors)
Console.WriteLine("If you want to get to {0} you have to enter through the in edge {1}", kvp.Key, kvp.Value);
// Remember to detach the observers
// distObserver.Detach(dijkstra);
// predecessorObserver.Detach(dijkstra);
// Visualize the Graph
var graphviz = new GraphvizAlgorithm<string, Edge<string>>(graph);
graphviz.ImageType = GraphvizImageType.Jpeg;
// render
string outputString = graphviz.Generate();
string output = graphviz.Generate(new FileDotEngine(), "MyGraph");
}
public void CreateGraph()
{
graph = new AdjacencyGraph<string, Edge<string>>(true);
// Add some vertices to the graph
graph.AddVertex("A");
graph.AddVertex("B");
graph.AddVertex("D");
graph.AddVertex("C");
graph.AddVertex("E");
// Create the edges
var a_b = new Edge<string>("A", "B");
var a_c = new Edge<string>("A", "C");
var b_e = new Edge<string>("B", "E");
var c_d = new Edge<string>("C", "D");
var d_e = new Edge<string>("D", "E");
// Add edges to the graph
graph.AddEdge(a_b);
graph.AddEdge(a_c);
graph.AddEdge(c_d);
graph.AddEdge(d_e);
graph.AddEdge(b_e);
// Define some weights to the edges
var weight = new Dictionary<Edge<string>, double>(graph.EdgeCount);
weight.Add(a_b, 30);
weight.Add(a_c, 30);
weight.Add(b_e, 60);
weight.Add(c_d, 40);
weight.Add(d_e, 4);
algo = new DijkstraShortestPathAlgorithm<string, Edge<string>>(graph, e => weight[e]);
// Attach a Vertex Predecessor Recorder Observer to give us the paths
predecessorObserver = new VertexPredecessorRecorderObserver<string, Edge<string>>();
using (predecessorObserver.Attach(algo))
// Run the algorithm with A set to be the source
algo.Compute("A");
Assert.IsTrue(algo.Distances["E"] == 74);
}
/// <summary>
/// Carries out the shortest path between the two nodes
/// ids passed as variables and returns an <see cref="ILineString" />
/// giveing the shortest path.
/// </summary>
/// <param name="source">The source node</param>
/// <param name="destination">The destination node</param>
/// A <see cref="ILineString"/> or a <see cref="IMultiLineString"/>
/// with all the elements of the graph that composes the shortest path,
/// sequenced using a <see cref="LineSequencer"/>.
/// </returns>
public IGeometry Find(Coordinate source, Coordinate destination)
{
if (!graph.ContainsVertex(source))
throw new ArgumentException("key not found in the graph", "source");
if (!graph.ContainsVertex(destination))
throw new ArgumentException("key not found in the graph", "destination");
// Build algorithm
var dijkstra =
new DijkstraShortestPathAlgorithm<Coordinate, IEdge<Coordinate>>(graph, edge => consts[edge]);
// Attach a Distance observer to give us the distances between edges
var distanceObserver =
new VertexDistanceRecorderObserver<Coordinate, IEdge<Coordinate>>(edge => consts[edge]);
distanceObserver.Attach(dijkstra);
// Attach a Vertex Predecessor Recorder Observer to give us the paths
var predecessorObserver =
new VertexPredecessorRecorderObserver<Coordinate, IEdge<Coordinate>>();
predecessorObserver.Attach(dijkstra);
// Run the algorithm with A set to be the source
dijkstra.Compute(source);
// Get the path computed to the destination.
IEnumerable<IEdge<Coordinate>> path;
var result = predecessorObserver.TryGetPath(destination, out path);
// Then we need to turn that into a geomery.
return result ? BuildString(new List<IEdge<Coordinate>>(path)) : null;
}
public void Compute()
{
var g = new AdjacencyGraph<char, Edge<char>>();
var distances = new Dictionary<Edge<char>, double>();
g.AddVertexRange("ABCDE");
AddEdge(g, distances, 'A', 'C', 1);
AddEdge(g, distances, 'B', 'B', 2);
AddEdge(g, distances, 'B', 'D', 1);
AddEdge(g, distances, 'B', 'E', 2);
AddEdge(g, distances, 'C', 'B', 7);
AddEdge(g, distances, 'C', 'D', 3);
AddEdge(g, distances, 'D', 'E', 1);
AddEdge(g, distances, 'E', 'A', 1);
AddEdge(g, distances, 'E', 'B', 1);
var dijkstra = new DijkstraShortestPathAlgorithm<char, Edge<char>>(g, distances);
var predecessors = new VertexPredecessorRecorderObserver<char, Edge<char>>();
predecessors.Attach(dijkstra);
dijkstra.Compute('A');
Assert.AreEqual(0, dijkstra.Distances['A']);
Assert.AreEqual(6, dijkstra.Distances['B']);
Assert.AreEqual(1, dijkstra.Distances['C']);
Assert.AreEqual(4, dijkstra.Distances['D']);
Assert.AreEqual(5, dijkstra.Distances['E']);
}
public void CreateAlgorithmWithNullGraph()
{
DijkstraShortestPathAlgorithm dij = new DijkstraShortestPathAlgorithm(null,null);
}
public void CreateAlgorithmWithNullWeights()
{
AdjacencyGraph<int, Edge<int>> g = new AdjacencyGraph<int, Edge<int>>(true);
DijkstraShortestPathAlgorithm<int, Edge<int>> dij =
new DijkstraShortestPathAlgorithm<int, Edge<int>>(g, null);
}
public void CreateAlgorithmWithNullWeights()
{
AdjacencyGraph g = new AdjacencyGraph(true);
DijkstraShortestPathAlgorithm dij = new DijkstraShortestPathAlgorithm(g,null);
}
public void CheckPredecessorLineGraph()
{
AdjacencyGraph<int, Edge<int>> g = new AdjacencyGraph<int, Edge<int>>(true);
g.AddVertex(1);
g.AddVertex(2);
g.AddVertex(3);
Edge<int> e12 = new Edge<int>(1, 2); g.AddEdge(e12);
Edge<int> e23 = new Edge<int>(2, 3); g.AddEdge(e23);
Dictionary<Edge<int>, double> weights =
DijkstraShortestPathAlgorithm<int, Edge<int>>.UnaryWeightsFromEdgeList(g);
DijkstraShortestPathAlgorithm<int, Edge<int>> dij = new DijkstraShortestPathAlgorithm<int, Edge<int>>(g, weights);
VertexPredecessorRecorderObserver<int, Edge<int>> vis = new VertexPredecessorRecorderObserver<int, Edge<int>>();
vis.Attach(dij);
dij.Compute(1);
IList<Edge<int>> col = vis.Path(2);
Assert.AreEqual(1, col.Count);
Assert.AreEqual(e12, col[0]);
col = vis.Path(3);
Assert.AreEqual(2, col.Count);
Assert.AreEqual(e12, col[0]);
Assert.AreEqual(e23, col[1]);
}
public void CreateAlgorithmWithNullGraph()
{
DijkstraShortestPathAlgorithm <int, Edge <int> > dij = new
DijkstraShortestPathAlgorithm <int, Edge <int> >(null, null);
}
public void Scenario()
{
AdjacencyGraph<string, Edge<string>> graph = new AdjacencyGraph<string, Edge<string>>(true);
// Add some vertices to the graph
graph.AddVertex("A");
graph.AddVertex("B");
graph.AddVertex("C");
graph.AddVertex("D");
graph.AddVertex("E");
graph.AddVertex("F");
graph.AddVertex("G");
graph.AddVertex("H");
graph.AddVertex("I");
graph.AddVertex("J");
// Create the edges
Edge<string> a_b = new Edge<string>("A", "B");
Edge<string> a_d = new Edge<string>("A", "D");
Edge<string> b_a = new Edge<string>("B", "A");
Edge<string> b_c = new Edge<string>("B", "C");
Edge<string> b_e = new Edge<string>("B", "E");
Edge<string> c_b = new Edge<string>("C", "B");
Edge<string> c_f = new Edge<string>("C", "F");
Edge<string> c_j = new Edge<string>("C", "J");
Edge<string> d_e = new Edge<string>("D", "E");
Edge<string> d_g = new Edge<string>("D", "G");
Edge<string> e_d = new Edge<string>("E", "D");
Edge<string> e_f = new Edge<string>("E", "F");
Edge<string> e_h = new Edge<string>("E", "H");
Edge<string> f_i = new Edge<string>("F", "I");
Edge<string> f_j = new Edge<string>("F", "J");
Edge<string> g_d = new Edge<string>("G", "D");
Edge<string> g_h = new Edge<string>("G", "H");
Edge<string> h_g = new Edge<string>("H", "G");
Edge<string> h_i = new Edge<string>("H", "I");
Edge<string> i_f = new Edge<string>("I", "F");
Edge<string> i_j = new Edge<string>("I", "J");
Edge<string> i_h = new Edge<string>("I", "H");
Edge<string> j_f = new Edge<string>("J", "F");
// Add the edges
graph.AddEdge(a_b);
graph.AddEdge(a_d);
graph.AddEdge(b_a);
graph.AddEdge(b_c);
graph.AddEdge(b_e);
graph.AddEdge(c_b);
graph.AddEdge(c_f);
graph.AddEdge(c_j);
graph.AddEdge(d_e);
graph.AddEdge(d_g);
graph.AddEdge(e_d);
graph.AddEdge(e_f);
graph.AddEdge(e_h);
graph.AddEdge(f_i);
graph.AddEdge(f_j);
graph.AddEdge(g_d);
graph.AddEdge(g_h);
graph.AddEdge(h_g);
graph.AddEdge(h_i);
graph.AddEdge(i_f);
graph.AddEdge(i_h);
graph.AddEdge(i_j);
graph.AddEdge(j_f);
// Define some weights to the edges
Dictionary<Edge<string>, double> edgeCost = new Dictionary<Edge<string>, double>(graph.EdgeCount);
edgeCost.Add(a_b, 4);
edgeCost.Add(a_d, 1);
edgeCost.Add(b_a, 74);
edgeCost.Add(b_c, 2);
edgeCost.Add(b_e, 12);
edgeCost.Add(c_b, 12);
edgeCost.Add(c_f, 74);
edgeCost.Add(c_j, 12);
edgeCost.Add(d_e, 32);
edgeCost.Add(d_g, 22);
edgeCost.Add(e_d, 66);
edgeCost.Add(e_f, 76);
edgeCost.Add(e_h, 33);
edgeCost.Add(f_i, 11);
edgeCost.Add(f_j, 21);
edgeCost.Add(g_d, 12);
edgeCost.Add(g_h, 10);
edgeCost.Add(h_g, 2);
edgeCost.Add(h_i, 72);
edgeCost.Add(i_f, 31);
edgeCost.Add(i_h, 18);
edgeCost.Add(i_j, 7);
edgeCost.Add(j_f, 8);
// We want to use Dijkstra on this graph
var dijkstra = new DijkstraShortestPathAlgorithm<string, Edge<string>>(graph, e => edgeCost[e]);
// Attach a Vertex Predecessor Recorder Observer to give us the paths
var predecessorObserver = new VertexPredecessorRecorderObserver<string, Edge<string>>();
using (predecessorObserver.Attach(dijkstra)) {
// Run the algorithm with A set to be the source
dijkstra.Compute("A");
}
foreach (KeyValuePair<string, Edge<string>> kvp in predecessorObserver.VertexPredecessors)
Console.WriteLine("If you want to get to {0} you have to enter through the in edge {1}", kvp.Key, kvp.Value);
foreach (string v in graph.Vertices) {
double distance =
AlgorithmExtensions.ComputePredecessorCost(
predecessorObserver.VertexPredecessors,
edgeCost,v);
Console.WriteLine("A -> {0}: {1}", v, distance);
}
}
private IEnumerable<Edge<Node>> FindShortestPath(Node source, Node target)
{
Func<Edge<Node>, double> edgeCost = e => e.Source.GetDistance(e.Target);
var dijkstra = new DijkstraShortestPathAlgorithm<Node, Edge<Node>>(_graph, edgeCost);
var predecessors = new VertexPredecessorRecorderObserver<Node, Edge<Node>>();
using (predecessors.Attach(dijkstra))
{
dijkstra.Compute(source);
}
IEnumerable<Edge<Node>> path;
predecessors.TryGetPath(target, out path);
return path;
}
static void Test2(InputMode pIM)
{
string filePath = null;
System.IO.StreamReader sR = null;
Console.WriteLine();
if (pIM == InputMode.CLI)
{
Console.WriteLine("Please enter your query in the form of:");
Console.WriteLine("\t>: number n of cities in the graph (beginning at 0)");
Console.WriteLine("\t>: number m of unidirectinal prexisting roads");
Console.WriteLine("\t>: NEXT M LINES: <city1>:<city2>:<road length>");
Console.WriteLine("\t>: number k of optional unidirectional roads");
Console.WriteLine("\t>: NEXT K LINES: <city1>:<city2>:<road length>");
Console.WriteLine("\t>: s (source city)");
Console.WriteLine("\t>: t (target city)");
}
else
{
Console.WriteLine("Please enter the path of the file to pull input from.");
filePath = Console.ReadLine();
while (!File.Exists(filePath))
{
Console.WriteLine("That file appears to not exist. Try again.");
filePath = Console.ReadLine();
}
while (IsFileinUse(filePath))
{
Console.WriteLine("File is currently in use. Please close it and press enter.");
Console.ReadLine();
}
sR = new System.IO.StreamReader(filePath);
}
AdjacencyGraph<string, Edge<string>> graph = new AdjacencyGraph<string, Edge<string>>(true);
// Transpose graph
AdjacencyGraph<string, Edge<string>> tGraph = new AdjacencyGraph<string, Edge<string>>(true);
Dictionary<Edge<string>, double> edgeCost = new Dictionary<Edge<string>, double>();
Dictionary<Edge<string>, double> tEdgeCost = new Dictionary<Edge<string>, double>();
int n = Convert.ToInt32((pIM == InputMode.CLI) ? Console.ReadLine() : sR.ReadLine());
for (int i = 0; i < n; i++)
{
AddNodeToBoth(graph, tGraph, ""+i);
}
int m = Convert.ToInt32((pIM == InputMode.CLI) ? Console.ReadLine() : sR.ReadLine());
char[] splitChars = {':'};
string[] theParts;
for (int i = 0; i < m; i++)
{
theParts = ((pIM == InputMode.CLI) ? Console.ReadLine() : sR.ReadLine()).Replace(" ", "").Replace("\t", "").Split(splitChars);
AddEdgeToBoth(graph, tGraph, edgeCost, tEdgeCost, theParts[0], theParts[1], Convert.ToInt32(theParts[2]));
}
int k = Convert.ToInt32(((pIM == InputMode.CLI) ? Console.ReadLine() : sR.ReadLine()));
Stack<string[]> optionalEdgeStack = new Stack<string[]>();
for (int i = 0; i < k; i++)
{
optionalEdgeStack.Push(((pIM == InputMode.CLI) ? Console.ReadLine() : sR.ReadLine()).Replace(" ", "").Replace("\t", "").Split(splitChars));
}
string source = ((pIM == InputMode.CLI) ? Console.ReadLine() : sR.ReadLine());
string target = ((pIM == InputMode.CLI) ? Console.ReadLine() : sR.ReadLine());
System.Func<Edge<String>, double> EdgeCostFunct = (QuickGraph.Edge<string> input) => { return (edgeCost.ContainsKey(input)) ? edgeCost[input] : 1000.0; };
System.Func<Edge<String>, double> EdgeCostFunct2 = (QuickGraph.Edge<string> input) => { return (tEdgeCost.ContainsKey(input)) ? tEdgeCost[input] : 1000.0; };
//FORWARD SEARCH
// We want to use Dijkstra on this graph
DijkstraShortestPathAlgorithm<string, Edge<string>> dijkstra = new DijkstraShortestPathAlgorithm<string, Edge<string>>(graph, EdgeCostFunct);
// attach a distance observer to give us the shortest path distances
VertexDistanceRecorderObserver<string, Edge<string>> distObserver = new VertexDistanceRecorderObserver<string, Edge<string>>(EdgeCostFunct);
distObserver.Attach(dijkstra);
// Attach a Vertex Predecessor Recorder Observer to give us the paths
VertexPredecessorRecorderObserver<string, Edge<string>> predecessorObserver = new VertexPredecessorRecorderObserver<string, Edge<string>>();
predecessorObserver.Attach(dijkstra);
//BACKWARD SEARCH
// We want to use Dijkstra on this graph
DijkstraShortestPathAlgorithm<string, Edge<string>> dijkstra2 = new DijkstraShortestPathAlgorithm<string, Edge<string>>(tGraph, EdgeCostFunct2);
// attach a distance observer to give us the shortest path distances
VertexDistanceRecorderObserver<string, Edge<string>> distObserver2 = new VertexDistanceRecorderObserver<string, Edge<string>>(EdgeCostFunct2);
distObserver2.Attach(dijkstra2);
// Attach a Vertex Predecessor Recorder Observer to give us the paths
VertexPredecessorRecorderObserver<string, Edge<string>> predecessorObserver2 = new VertexPredecessorRecorderObserver<string, Edge<string>>();
predecessorObserver2.Attach(dijkstra2);
// Run the algorithm with starname set to be the source
dijkstra.Compute(source);
if (distObserver.Distances.ContainsKey(target) == false)
{
Console.WriteLine(target + " is unreachable");
}
else
{
dijkstra2.Compute(target);
double initialPathLength = distObserver.Distances[target];
Stack<string> viablePathAdditions = new Stack<string>();
string currentMinEdgeAddition = "";
double currentMinEdgeWeight = -1.0;
while (optionalEdgeStack.Count > 0)
{
string[] triple = optionalEdgeStack.Pop();
if (distObserver.Distances.ContainsKey(triple[0]) && distObserver2.Distances.ContainsKey(triple[1]))
{
double total = distObserver.Distances[triple[0]] + distObserver2.Distances[triple[1]] + (double)Int32.Parse(triple[2]);
if (total < initialPathLength)
{
viablePathAdditions.Push(triple[0] + ':' + triple[1]);
if (currentMinEdgeWeight < 0 || total < currentMinEdgeWeight)
{
currentMinEdgeWeight = total;
currentMinEdgeAddition = triple[0] + ':' + triple[1];
}
}
}
}
if (viablePathAdditions.Count > 0)
{
Console.WriteLine("Additions that would lower path length.");
while (viablePathAdditions.Count > 0)
{
Console.WriteLine(viablePathAdditions.Pop());
}
Console.WriteLine("The cost-minimizing addition is:");
Console.WriteLine(currentMinEdgeAddition);
}
else
{
Console.WriteLine("There are no additions that would minimize path length.");
}
}
Console.WriteLine("");
Console.WriteLine("Press enter to return to the main menu.");
Console.ReadLine();
if (sR != null) sR.Close();
}
bool findBestPath(SetupStore ss)
{
Dictionary<RoutingGraph.Link, double> edgeCost = new Dictionary<RoutingGraph.Link, double>(ss.ownTopology.EdgeCount);
int index = 0;
int max = ss.ownTopology.EdgeCount;
while (index < max)
{ //free capisity < requierd
if (ss.ownTopology.Edges.ElementAt(index).Capacity < ss.requieredCapacity)
{
ss.ownTopology.RemoveEdge(ss.ownTopology.Edges.ElementAt(index));
max = ss.ownTopology.EdgeCount;
}
else
index++;
}
foreach (var e in ss.ownTopology.Edges)
{
edgeCost.Add(e, e.Capacity);
}
var dijkstra = new DijkstraShortestPathAlgorithm<RoutingGraph.Node, RoutingGraph.Link>(ss.ownTopology, e => edgeCost[e]);
var predecessor = new VertexPredecessorRecorderObserver<RoutingGraph.Node, RoutingGraph.Link>();
predecessor.Attach(dijkstra);
dijkstra.Compute(this.IDtoNode(ss.source, ss.ownTopology));
IEnumerable<RoutingGraph.Link> path;
if (predecessor.TryGetPath(this.IDtoNode(ss.target, ss.ownTopology), out path))
{
ss.path.AddRange(path);
return true;
}
else return false;
}
