I'm studying certain properties of graphs but I want to work with unlabelled ones i.e. I do not want to distinguish graphs that differs only by the numbering of vertices, which is the case by default if I have correctly understood. Is it possible?
Thanks
It's unclear what do you mean under "distinguish". If it's about creation/generation of unlabeled graphs, then many graph construction methods produce unlabeled (di)graphs. If it's about comparison of unlabeled graphs, then this can be done via comparison of their canonical labels (.canonical_label()). So, example of what you want to achieve would be helpful.
Nauty has a generator of graphs up to isomorphism.
Sage has an interface to it.
See the nauty_geng function:
Graphs have the method is_isomorphic : G1.is_isomorphic(G2) is True if G2 is a relabelling of G1. I am not aware of a built-in way to designate the equivalence classes thus defined :however, my knowledge of (this part of) Sage is quite superficial.
Canonical representatives of the equivalence classes are produced by .canonical_label().
Asked: 3 years ago
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Last updated: Sep 15 '21
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