[graph-tool] Problems using the dijktstra search

Nasgar josubg at gmail.com
Mon Jul 16 12:39:52 CEST 2012


Thanks a lot!

I can get the correct distances normal nodes  but I'm getting distances for
not reachable nodes. These distances are high compared with the others
distances (cost 140 against a mean cost of 5) but nothing that can
be programmatic filtered (like a constant inf value or negative value). If
I put infinity=-1 all distances changes to -1 (also the reachable nodes).
If is use a big infinity like 100000, the unreachable nodes get this
distance.

Is this the expected result of the function?

On Thu, Jul 12, 2012 at 6:52 PM, Tiago de Paula Peixoto <tiago at skewed.de>wrote:

> On 07/12/2012 01:14 PM, josubg wrote:
> > Hi all.
> >
> > I'm trying to use the dijktstra search But I have a exception.The
> property
> > that is used a int32_t and the GraphViews aren't empty. Any clue of
>  what is
> > my error?
> >
> > This is the code:
> >
> >         referents_graph = GraphView(graph, vfilt= lambda v:
> > graph.vertex_properties["type"][v]=="referent")
> >         navigable_graph = GraphView(graph, reversed=True)
> >
> >         referents = referents_graph.vertices()
> >         weight = navigable_graph.edge_properties["weight"]
> >
> >         for base_referent in referents:
> >             # Calculate the distance of all accessible referents
> >             distances, predecessors =
> > graph_tool.search.dijkstra_search(navigable_graph,base_referent,weight)
>
> This has been fixed now in git... As a workaround, you can also do the
> following:
>
>      dijkstra_search(navigable_graph,base_referent,weight,
> infinity=1000000)
>
> Where the infinity value is a suitably large number.
>
> Cheers,
> Tiago
>
> --
> Tiago de Paula Peixoto <tiago at skewed.de>
>
>
>
>
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>
>
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