random_cograph(n, seed=None)[source]

Returns a random cograph with \(2 ^ n\) nodes.

A cograph is a graph containing no path on four vertices. Cographs or \(P_4\)-free graphs can be obtained from a single vertex by disjoint union and complementation operations.

This generator starts off from a single vertex and performes disjoint union and full join operations on itself. The decision on which operation will take place is random.

  • n (int) – The order of the cograph.

  • seed (integer, random_state, or None (default)) – Indicator of random number generation state. See Randomness.



Return type

A random graph containing no path on four vertices.

See also

full_join(), union()



D.G. Corneil, H. Lerchs, L.Stewart Burlingham, “Complement reducible graphs”, Discrete Applied Mathematics, Volume 3, Issue 3, 1981, Pages 163-174, ISSN 0166-218X.