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Re: Is this a bug in the Adjacency Matrix function? Using 8.9.4.0

• To: mathgroup at smc.vnet.net
• Subject: [mg123981] Re: Is this a bug in the Adjacency Matrix function? Using 8.9.4.0
• From: Heike Gramberg <heike.gramberg at gmail.com>
• Date: Wed, 4 Jan 2012 04:59:41 -0500 (EST)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.com
• References: <201201031029.FAA20259@smc.vnet.net>

VertexList[testgraph] returns {1, 3, 2, 4, 5, 6, 7}, so the second row 
and column in the adjacency list corresponds
to the vertex with label 3, and vice versa. If you want to make sure 
that the vertices are in the right order, you could
do something like

testgraph = Graph[
  Range[7], #[[1]] \[DirectedEdge] #[[2]] & /@ {{1, 3}, {2, 3}, {3,
     4}, {3, 5}, {4, 6}, {4, 7}, {5, 7}, {6, 7}},
  VertexLabels -> "Name", ImagePadding -> 10]

Heike


On 3 Jan 2012, at 11:29, Richard Palmer wrote:

> 
testgraph=Graph[#[[1]]\[DirectedEdge]#[[2]]&/@{{1,3},{2,3},{3,4},{3,5},{4,6},{4,7},{5,7},{6,7}},
> VertexLabels->"Name",
> ImagePadding->10]
>
>
> MatrixForm[AdjacencyMatrix[testgraph],
> TableHeadings -> {Range[7], Range[7]}]
>
>
> The Adjacency Matrix appears to be incorrect, e.g.  1 is not adjacent to 2.
> What am I missing?

• References:
  • Is this a bug in the Adjacency Matrix function? Using 8.9.4.0
    • From: Richard Palmer <rhpalmer@gmail.com>