A small Julia wrapper for nauty



Simple wrapper for using nauty, a graph isomorphism package, with LightGraphs in Julia. Requires gcc and a POSIX style build environment.

Currently under development. Interface may change / break by the day.

Example usage

Check if two graphs are isomorphs of each other:

baked_canonical_form(g1).canong == baked_canonical_form(g2).canong

LightGraphs interface:

using Nauty
BenchmarkTools.@btime LightGraphs.Experimental.has_isomorph(g1,g2,alg=NautyAlg())

If you need to provide custom options to nauty, use densenauty(g, optionblk(optionblk_mutable(DEFAULTOPTIONS_GRAPH))), but be aware that it is around 2-4x slower than using baked in options as Julia cannot optimise across the C boundary. Consider baking your own.


  • Friendlier return types
  • NautyGraph -> LightGraph
  • MetaGraph -> (NautyGraph, labels, partition)
  • isomorphOf() / congruence operator
  • Documentation (documenter.jl)
  • Pick a licence
  • More comprehensive tests if we feel like it
  • Build options
    • Test MAXN=WORDSIZE optimisation effect. Build nauty twice if it matters, once with MAXN=0 if not
  • Use baked_canonical_form automatically


canonical_isomorph(g: LightGraph) -> g' canonical_isomorph(g: ColouredGraph) -> g' - We'll have to use the relabelling information to make g'

isisomorph(g1, g2) -> bool operator overload (congruence sign?)

nauty(g, options) -> all the stuff nauty gives

First Commit


Last Touched

6 months ago


79 commits

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