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Re: All pairs shortest paths

• To: mathgroup at smc.vnet.net
• Subject: [mg111396] Re: All pairs shortest paths
• From: "Jon Harrop" <usenet at ffconsultancy.com>
• Date: Fri, 30 Jul 2010 06:57:32 -0400 (EDT)
• References: <i2eaij$q7d$1@smc.vnet.net> <i2jq2j$gr8$1@smc.vnet.net>

"Murta" <rodrigomurtax at gmail.com> wrote in message 
news:i2jq2j$gr8$1 at smc.vnet.net...
> Try the Graph Utilities Package. There are some commands that can
> help.
>
> GraphDistance[g,start,end] give the distance from vertex i to vertex j
> in the graph g
> GraphPath[g,start,end] find a shortest path between vertices start and
> end in graph g
> GraphDistanceMatrix[g] give a matrix in which the (i,j)\[Null]^th
> entry is the length of a shortest path in g between vertices i and j
> GraphDistanceMatrix[g,Parent] return a three-dimensional matrix in
> which the (1,i,j)\[Null]^th entry is the length of a shortest path
> from i to j and the (2,i,j)\[Null]^th entry is the predecessor of j in
> a shortest path from i to j.

Sure, but none of those actually implement what I need. The last one returns 
a data structure that can be used to compose the information I need but I'd 
have to do the rest of the computation myself and it would run like a dog if 
written in Mathematica.

Does Mathematica really not provide a built-in function to compute all-pairs 
shortest paths?

Cheers,
Jon.