protected void Initialize()
{
this.costs = new VertexDoubleDictionary();
this.priorityQueue = new PriorithizedVertexBuffer(costs);
this.unvisitedSuccessorCounts = new VertexIntDictionary();
this.states.Clear();
foreach (IVertex v in this.goals)
{
this.costs.Add(v, 0);
this.priorityQueue.Push(v);
}
foreach (IVertex v in this.NotGoals)
{
this.costs.Add(v, double.PositiveInfinity);
}
foreach (IVertex v in this.TestGraph.ChoicePoints)
{
this.unvisitedSuccessorCounts.Add(v, this.testGraph.Graph.OutDegree(v));
}
foreach (IVertex v in this.TestGraph.Graph.Vertices)
{
this.states.Add(v, null);
}
}
private static void swapRanks(VertexDoubleDictionary left, VertexDoubleDictionary right)
{
VertexDoubleDictionary temp = left;
left = right;
right = temp;
}
/// <summary>
///
/// </summary>
/// <param name="g"></param>
/// <param name="capacities"></param>
/// <param name="reversedEdges"></param>
public PushRelabelMaximumFlowAlgorithm(
IIndexedVertexListGraph g,
EdgeDoubleDictionary capacities,
EdgeEdgeDictionary reversedEdges
)
: base(g, capacities, reversedEdges)
{
this.visitedGraph = g;
this.excessFlow = new VertexDoubleDictionary();
this.current = new VertexIntDictionary();
this.distances = new VertexIntDictionary();
}
private bool IsFlow(MaximumFlowAlgorithm maxFlow)
{
// check edge flow values
foreach (IVertex u in maxFlow.VisitedGraph.Vertices)
{
foreach (IEdge a in maxFlow.VisitedGraph.OutEdges(u))
{
if (maxFlow.Capacities[a] > 0)
if ((maxFlow.ResidualCapacities[a] + maxFlow.ResidualCapacities[maxFlow.ReversedEdges[a]]
!= maxFlow.Capacities[a])
|| (maxFlow.ResidualCapacities[a] < 0)
|| (maxFlow.ResidualCapacities[maxFlow.ReversedEdges[a]] < 0))
return false;
}
}
// check conservation
VertexDoubleDictionary inFlows = new VertexDoubleDictionary();
VertexDoubleDictionary outFlows = new VertexDoubleDictionary();
foreach (IVertex u in maxFlow.VisitedGraph.Vertices)
{
inFlows[u] = 0;
outFlows[u] = 0;
}
foreach (IVertex u in maxFlow.VisitedGraph.Vertices)
{
foreach (IEdge e in maxFlow.VisitedGraph.OutEdges(u))
{
if (maxFlow.Capacities[e] > 0)
{
double flow = maxFlow.Capacities[e] - maxFlow.ResidualCapacities[e];
inFlows[e.Target] += flow;
outFlows[e.Source] += flow;
}
}
}
foreach (IVertex u in maxFlow.VisitedGraph.Vertices)
{
if (u != source && u != sink)
if (inFlows[u] != outFlows[u])
return false;
}
return true;
}
/// <summary>
/// Builds a new Bellman Ford searcher.
/// </summary>
/// <param name="g">The graph</param>
/// <param name="weights">Edge weights</param>
/// <exception cref="ArgumentNullException">Any argument is null</exception>
/// <remarks>This algorithm uses the <seealso cref="BreadthFirstSearchAlgorithm"/>.</remarks>
public BellmanFordShortestPathAlgorithm(
IVertexAndEdgeListGraph g,
EdgeDoubleDictionary weights
)
{
if (weights == null)
{
throw new ArgumentNullException("Weights");
}
m_VisitedGraph = g;
m_Colors = new VertexColorDictionary();
m_Weights = weights;
m_Distances = new VertexDoubleDictionary();
m_Predecessors = new VertexVertexDictionary();
}
/// <summary>
/// Computes the PageRank over the <see cref="VisitedGraph"/>.
/// </summary>
public void Compute()
{
VertexDoubleDictionary tempRanks = new VertexDoubleDictionary();
// create filtered graph
FilteredBidirectionalGraph fg = new FilteredBidirectionalGraph(
this.VisitedGraph,
Preds.KeepAllEdges(),
new InDictionaryVertexPredicate(this.ranks)
);
int iter = 0;
double error = 0;
do
{
// compute page ranks
error = 0;
foreach (DictionaryEntry de in this.Ranks)
{
IVertex v = (IVertex)de.Key;
double rank = (double)de.Value;
// compute ARi
double r = 0;
foreach (IEdge e in fg.InEdges(v))
{
r += this.ranks[e.Source] / fg.OutDegree(e.Source);
}
// add sourceRank and store
double newRank = (1 - this.damping) + this.damping * r;
tempRanks[v] = newRank;
// compute deviation
error += Math.Abs(rank - newRank);
}
// swap ranks
VertexDoubleDictionary temp = ranks;
ranks = tempRanks;
tempRanks = temp;
iter++;
}while(error > this.tolerance && iter < this.maxIterations);
Console.WriteLine("{0}, {1}", iter, error);
}
/// <summary>
/// Builds a new Dijsktra searcher.
/// </summary>
/// <param name="g">The graph</param>
/// <param name="weights">Edge weights</param>
/// <exception cref="ArgumentNullException">Any argument is null</exception>
/// <remarks>This algorithm uses the <seealso cref="BreadthFirstSearchAlgorithm"/>.</remarks>
public DijkstraShortestPathAlgorithm(
IVertexListGraph g,
EdgeDoubleDictionary weights
)
{
if (g == null)
{
throw new ArgumentNullException("g");
}
if (weights == null)
{
throw new ArgumentNullException("Weights");
}
this.visitedGraph = g;
this.colors = new VertexColorDictionary();
this.distances = new VertexDoubleDictionary();
this.weights = weights;
this.vertexQueue = null;
}
/// <summary>
/// Builds a new Dijsktra searcher.
/// </summary>
/// <param name="g">The graph</param>
/// <param name="weights">Edge weights</param>
/// <exception cref="ArgumentNullException">Any argument is null</exception>
/// <remarks>This algorithm uses the <seealso cref="BreadthFirstSearchAlgorithm"/>.</remarks>
public DijkstraShortestPathAlgorithm(
IVertexListGraph g,
EdgeDoubleDictionary weights
)
{
if (g == null)
{
throw new ArgumentNullException("g");
}
if (weights == null)
{
throw new ArgumentNullException("Weights");
}
m_VisitedGraph = g;
m_Colors = new VertexColorDictionary();
m_Distances = new VertexDoubleDictionary();
m_Predecessors = new VertexVertexDictionary();
m_Weights = weights;
m_VertexQueue = null;
}