public void PriceUpdate(PriceUpdate update)
{
lock (lockTheEntireGraph)
{
var from = new ExchangeCurrency(update.Exchange, update.SourceCurrency);
var to = new ExchangeCurrency(update.Exchange, update.DestinationCurrency);
double weight = -Math.Log(update.Factor);
var oldEdge = graph.Adj(from).Where(e => e.To().CompareTo(to) == 0).SingleOrDefault();
var newEdge = new Edge <ExchangeCurrency>(from, to, weight, update.Timestamp);
if (oldEdge != null && oldEdge.TimeStamp < update.Timestamp)
{
graph.RemoveEdge(oldEdge);
graph.AddEdge(newEdge);
}
else if (oldEdge == null) // add 1<-->1 edges by currency
{
graph.AddEdge(newEdge);
foreach (var v in graph.Vertexes()
.Where(v => v.Currency == update.SourceCurrency)
.Where(v => v.CompareTo(from) != 0))
{
if (!graph.HasEdgeBetween(v, from))
{
graph.AddEdge(new Edge <ExchangeCurrency>(v, from, -Math.Log(1)));
}
if (!graph.HasEdgeBetween(from, v))
{
graph.AddEdge(new Edge <ExchangeCurrency>(from, v, -Math.Log(1)));
}
}
foreach (var v in graph.Vertexes()
.Where(v => v.Currency == update.DestinationCurrency)
.Where(v => v.CompareTo(to) != 0))
{
if (!graph.HasEdgeBetween(v, to))
{
graph.AddEdge(new Edge <ExchangeCurrency>(v, to, -Math.Log(1)));
}
if (!graph.HasEdgeBetween(to, v))
{
graph.AddEdge(new Edge <ExchangeCurrency>(to, v, -Math.Log(1)));
}
}
}
}
}
public void WeightedDiGraph_Smoke_Test()
{
var graph = new WeightedDiGraph <int, int>();
graph.AddVertex(1);
graph.AddVertex(2);
graph.AddVertex(3);
graph.AddVertex(4);
graph.AddVertex(5);
graph.AddEdge(1, 2, 1);
graph.AddEdge(2, 3, 2);
graph.AddEdge(3, 4, 3);
graph.AddEdge(4, 5, 1);
graph.AddEdge(4, 1, 6);
graph.AddEdge(3, 5, 4);
Assert.AreEqual(2, graph.GetAllOutEdges(4).Count);
Assert.AreEqual(2, graph.GetAllInEdges(5).Count);
Assert.AreEqual(5, graph.VerticesCount);
Assert.IsTrue(graph.HasEdge(1, 2));
graph.RemoveEdge(1, 2);
Assert.IsFalse(graph.HasEdge(1, 2));
graph.RemoveEdge(2, 3);
graph.RemoveEdge(3, 4);
graph.RemoveEdge(4, 5);
graph.RemoveEdge(4, 1);
Assert.IsTrue(graph.HasEdge(3, 5));
graph.RemoveEdge(3, 5);
Assert.IsFalse(graph.HasEdge(3, 5));
graph.RemoveVertex(1);
graph.RemoveVertex(2);
graph.RemoveVertex(3);
graph.RemoveVertex(4);
graph.AddEdge(5, 5, 5);
graph.RemoveEdge(5, 5);
graph.RemoveVertex(5);
Assert.AreEqual(0, graph.VerticesCount);
}
/// <summary>
/// getting rendom paths of only two-direction vertecies for testing
/// </summary>
/// <param name="Paths">empty list of paths to fill</param>
/// <returns></returns>
public List <int> GetPathsAdvancedIntersect(ref List <List <string> > Paths)
{
List <string> vertecies = new List <string>();
List <List <string> > edges = new List <List <string> >();
// get all vertecies and edges from DB
DBservices db = new DBservices();
vertecies = db.GetAllVertecies("TheMoleConnection", "MoviesVertecies");
edges = db.GetEdges("TheMoleConnection", "MoviesEdges");
//1. create a graph
var graph = new WeightedDiGraph <string, int>();
//2. insert vertecies to the graph
foreach (string vertex in vertecies)
{
graph.AddVertex(vertex);
}
//3. insert edges to the graph
foreach (var edge in edges)
{
graph.AddEdge(edge[0], edge[1], 1);
}
//remove one-direction edges
List <List <string> > twoDirectionsEdges = new List <List <string> >();
foreach (var edge in edges)
{
if (!graph.HasEdge(edge[1], edge[0]))
{
graph.RemoveEdge(edge[0], edge[1]);
}
if (graph.HasEdge(edge[1], edge[0]))
{
twoDirectionsEdges.Add(edge);
}
}
//4. create dijkstra algorithm
var algorithm = new DijikstraShortestPath <string, int>(new DijikstraShortestPathOperators());
List <int> pathsCount = new List <int>();
//var result = algorithm.FindShortestPath(graph, Source, Target);
//pathsCount.Add(result.Path.Count);
//Paths.Add(result.Path
//5.run the algoritm for 110 random vertecies.
for (int i = 0; i < 200; i++)
{
int sourceVertex = random.Next(0, vertecies.Count);
int targetVertex = random.Next(0, vertecies.Count);
//if source and target pages are the same DON'T run the algorithm
if (sourceVertex != targetVertex)
{
var result = algorithm.FindShortestPath(graph, vertecies[sourceVertex], vertecies[targetVertex]);
pathsCount.Add(result.Path.Count);
Paths.Add(result.Path);
}
}
return(pathsCount);
}
