public virtual void RemoveVertex(T vertex)
{
if (vertex == null)
{
Log.Error("Vertex is null.");
return;
}
var affectedEdges = Edges
.Where(e => e.Source == vertex || e.Target == vertex)
.ToArray();
var neighbors = affectedEdges
.Select(e => e.Opposite(vertex))
.Except(new[] { vertex }); // a self edge would make the vertex its own neighbor
foreach (var edge in affectedEdges)
{
RemoveEdge(edge);
}
if (!VerticesData.Remove(vertex))
{
Log.Error("Vertex is not a member: " + vertex);
return;
}
// maintain root data
recalcIsTree = true;
RootVertices.Remove(vertex);
// add the targets that have no more in-edges
RootVertices.UnionWith(neighbors.Where(v => !HasParents(v)));
}
public virtual void AddEdge(Relation <T, P> relation)
{
if (relation == null || relation.Source == null || relation.Target == null)
{
Log.Error("Relation or vertex is null.");
return;
}
if (!VerticesData.ContainsKey(relation.Source))
{
Log.Error("Relation source is missing from the graph: " + relation.Source);
return;
}
if (!VerticesData.ContainsKey(relation.Target))
{
Log.Error("Relation target is missing from the graph: " + relation.Target);
return;
}
if (!Edges.Add(relation))
{
Log.Error("Relation is already part of the graph: " + relation);
return;
}
VerticesData[relation.Source].OutEdges.Add(relation);
VerticesData[relation.Target].InEdges.Add(relation);
// maintain root data
if (!relation.IsSelfRelation)
{
recalcIsTree = true;
RootVertices.Remove(relation.Target);
}
}