This method applies one of sixteen vertex invariant based refinements to a graph. See the nauty documentation for a more complete description of each and how the argument a is used.
The sixteen vertex invariants are:
i = 0: none,
i = 1: twopaths,
i = 2: adjtriang(K),
i = 3: triples,
i = 4: quadruples,
i = 5: celltrips,
i = 6: cellquads,
i = 7: cellquins,
i = 8: distances(K),
i = 9: indsets(K),
i = 10: cliques(K),
i = 11: cellcliq(K),
i = 12: cellind(K),
i = 13: adjacencies,
i = 14: cellfano, and
i = 15: cellfano2.
i1 : R = QQ[a..e]; |
i2 : G = graph {a*e, e*c, c*b, b*d, d*a}; |
i3 : relabelGraph G o3 = Graph{edges => {{a, b}, {a, c}, {b, d}, {c, e}, {d, e}}} ring => R vertices => {a, b, c, d, e} o3 : Graph |
Note that on most small graphs, all sixteen orderings produce the same result.