Dijkstra Visitor Concept| V | A type that is a model of Dijkstra Visitor. |
| vis | An object of type V. |
| G | A type that is a model of Graph. |
| g | An object of type G. |
| e | An object of type boost::graph_traits<G>::edge_descriptor. |
| s,u,v | An object of type boost::graph_traits<G>::vertex_descriptor. |
| DistanceMap | A type that is a model of Read/Write Property Map. |
| d | An object of type DistanceMap. |
| WeightMap | A type that is a model of Readable Property Map. |
| w | An object of type WeightMap. |
| Name | Expression | Return Type | Description |
|---|---|---|---|
| Initialize Vertex | vis.initialize_vertex(u, g) | void | This is invoked one each vertex of the graph when it is initialized. |
| Examine Vertex | vis.examine_vertex(u, g) | void | 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. |
| Examine Edge | vis.examine_edge(e, g) | void | This is invoked on every out-edge of each vertex after it is discovered. |
| Discover Vertex | vis.discover_vertex(u, g) | void | This is invoked when a vertex is encountered for the first time. |
| Edge Relaxed | vis.edge_relaxed(e, g) | void |
Upon examination, if the following condition holds then the edge
is relaxed (its distance is reduced), and this method is invoked. tie(u,v) = incident(e, g); D d_u = get(d, u), d_v = get(d, v); W w_e = get(w, e); assert(compare(combine(d_u, w_e), d_v)); |
| Edge Not Relaxed | vis.edge_not_relaxed(e, g) | void | Upon examination, if the edge is not relaxed (see above) then this method is invoked. |
| Finish Vertex | vis.finish_vertex(u, g) | void | 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). |
class count_tree_edges_dijkstra_visitor(bgl.Graph.DijkstraVisitor):
def __init__(self, name_map):
bgl.Graph.DijkstraVisitor.__init__(self)
self.name_map = name_map
def edge_relaxed(self, e, g):
(u, v) = (g.source(e), g.target(e))
print "Relaxed edge ",
print self.name_map[u],
print " -> ",
print self.name_map[v]
| Copyright © 2000-2001 |
Jeremy Siek,
Indiana University (jsiek@osl.iu.edu) Lie-Quan Lee, Indiana University (llee@cs.indiana.edu) Andrew Lumsdaine, Indiana University (lums@osl.iu.edu) |