induced subgraphs nautyhash

[JanPastorek]

Hi!

Thanks for this package, I happen to use it for my project. Is there a way to compute nauty hash of induced subgraph of a NautyGraph effectively (without allocating another graph)?

I use version 0.4 and I compute it like this:
induced_subg, _ = Graphs.induced_subgraph(g, comb)
grpsize, _, _, canon_hash_sub2 = NautyGraphs._nautyhash(induced_subg)

Thank you beforehand

[mxhbl]

Hi, I am afraid that is not possible at the moment. Nauty needs the graph to be stored in bit vector form, and I think you can't get around allocating that for a subgraph. There might be a way to avoid that with the sparse graph format of nauty, but that is not implemented in this package (yet).

Also, I don't know if this applies to you, but be careful that any subgraph constructors from Graphs.jl do not copy vertex labels to the returned graph. (#21). I will hopefully get around to fixing that soon.