Re: [pyton] how to use dijkstra's shortest path algorithm

On Feb 25, 2007, at 1:59 PM, Neeraj Shah wrote:

> Hi everyone,
>
> I am completely new to Boost, and have been playing with it through  
> the python bindings, but I'm getting a bit confused.
>
> What I'm trying to do is use dijkstra's shortest path algorithm  
> (with predecessor) on a graph I'm reading in from a graphviz file.  
> My code is as below:
>
> import boost.graph as bgl
>
> #Create a new graph from the graphviz file
> graph = bgl.Graph.read_graphviz('code/mst.dot')
> #try to get shortest path
> min_paths = bgl.dijkstra_shortest_paths(graph,graph.vertices.next 
> (),predecessorMap,distanceMap)

You'll need to initialize predecessorMap and distanceMap to  
something, e.g.,

	distanceMap = graph.add_vertex_property('distance')
	predecessorMap = graph.add_vertex_property('predecessor')

(Assuming you're using the Subversion version of BGL-Python; it's  
slightly different for 0.9)

	Cheers,
	Doug

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