Re: [graph-tool] Most efficient way to access all nodes in a block

Am 19.06.2018 um 21:01 schrieb Alexandre Hannud Abdo:

Ni! Hi Philipp,

Yes, there are more straightforward paths to the same information:

# get some graph and model it import graph_tool.all as gt g = gt.collection.data["celegansneural"] s = gt.minimize_nested_blockmodel_dl(g)

# get your groups of vertices in a dictionary l0 = s.levels[0] block2vertices = dict() for i in range(l0.B):     block2vertices[i] = gt.find_vertex(l0.g, l0.b, i)

Since find_vertex() is O(N), the above is O(B * N). A faster O(N) approach is simply: groups = defaultdict(list) for v in g.vertices(): groups[l0.b[v]].append(v) Best, Tiago -- Tiago de Paula Peixoto <tiago@skewed.de>