Beautiful two-communities-graph layout

gistfile1.py

import igraph

clusters_const = 2

graph = igraph.read("2_big_graph_clusters_ncol.txt", format="ncol", directed=False, names=True)

clusters = graph.community_edge_betweenness(clusters=2, directed=False)
splitter = clusters.as_clustering(clusters_const).membership
vs = igraph.VertexSeq(graph)

def get_community_map(community_id, color_to_be_set):
    map = {}
    for v, index in zip(vs, range(len(vs))):  #todo: get vertices ids from igraph.Vertex, not zipping
        if splitter[index] == community_id:
            map[index] = v['name']
            v['color'] = color_to_be_set
            v['label'] = v['name']
    return map

map_1 = get_community_map(0, (0.9, 1.0, 0.9))
map_2 = get_community_map(1, (0.9, 0.9, 1.0))

# printing communities labels
print "community of size", len(map_1), ",".join(map_1.values())
print "community of size", len(map_2), ",".join(map_2.values())

# printing intercluster connections
for c1 in map_1.keys():
    for c2 in map_2.keys():
        if graph.get_eid(c1, c2, directed=False, error=False) != -1:
            print map_1[c1], "--", map_2[c2],

# See for tuning http://igraph.org/python/doc/igraph.Graph-class.html#__plot__
igraph.plot(graph, vertex_frame_width=0.5, vertex_frame_color="gray", edge_width=0.5, edge_color="gray")