On 2/7/14 1:08 PM, kcrisman wrote:
    ...you get "True". Is this because is_transitive has a bug; because
    Sage doesn't like its directed graphs to have loops; because the
    is_transitive method is using a different definition of "transitive"
    than we are*, or what?


My guess is the loop issue.  Unfortunately the actual code for
is_transitive() seems to test all vertices (so not your "for example"
issue) but using a Cython function called c_distances.  Hopefully
Nathann has a quick answer - he is the guru of graphs :)

It appears the code is checking the distances between any two vertices. All distances should be 0, 1, or infinity, so it claims, for a transitive graph. However, I think a vertex is distance zero to itself, whether or not there is a loop. There's definitely a bug somewhere (in the docs or the code).

Jason

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