DijkstraVisitor#
- class graph_tool.search.DijkstraVisitor[source]#
Bases:
object
A visitor object that is invoked at the event-points inside the
dijkstra_search()
algorithm. By default, it performs no action, and should be used as a base class in order to be useful.Methods
This is invoked when a vertex is encountered for the first time.
Upon examination, if the edge is not relaxed (see
edge_relaxed()
) then this method is invoked.edge_relaxed
(e)Upon examination, if the following condition holds then the edge is relaxed (its distance is reduced), and this method is invoked.
examine_edge
(e)This is invoked on every out-edge of each vertex after it is discovered.
This is invoked on a vertex as it is popped from the queue.
This invoked on a vertex after all of its out edges have been added to the search tree and all of the adjacent vertices have been discovered (but before their out-edges have been examined).
This is invoked on every vertex of the graph before the start of the graph search.
- edge_not_relaxed(e)[source]#
Upon examination, if the edge is not relaxed (see
edge_relaxed()
) then this method is invoked.
- edge_relaxed(e)[source]#
Upon examination, if the following condition holds then the edge is relaxed (its distance is reduced), and this method is invoked.
(u, v) = tuple(e) assert compare(combine(d[u], weight[e]), d[v])
- examine_vertex(u)[source]#
This is invoked on a vertex as it is popped from the queue. This happens immediately before
examine_edge()
is invoked on each of the out-edges of vertex u.