I work a lot with (large, say, 5000 vertices) (di)graphs having large automorphism groups (often vertex-transitive, etc). Such graphs are very efficiently represented in GAP (via GRAPE) package. (one needs to keep representatives of arc orbits, and few other things, to be able to check adjacency of vertices, say) These kinds of graphs often arise in e.g. coding theory. Is there anything like this in Sage?
My primary use of Sage is an interface between GAP and cvxopt, so e.g. I can compute such graph invariants as Lovasz theta-function. The size of graphs makes it mandatory to use a compact representation, and "collapsed" adjacency matrices, that carry enough information about underlying algebra (e.g. graph eigenvalues). I wonder if Sage should get its own "graph with symmetries" class (unless there is already one...) Dima -- You received this message because you are subscribed to the Google Groups "sage-combinat-devel" group. To post to this group, send email to sage-combinat-de...@googlegroups.com. To unsubscribe from this group, send email to sage-combinat-devel+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sage-combinat-devel?hl=en.
