Basic test Merges: [ 1 2 0 3 ] Modularity: ( -0.333333 -0.222222 0 ) Membership: ( 0 0 0 ) Without modularity and membership calculation Merges: [ 1 2 0 3 ] Without merges matrix calculation Modularity: ( -0.333333 -0.222222 0 ) Bug 2042 Merges: [ 0 1 ] Modularity: ( -0.5 0 ) Membership: ( 0 0 1 ) Small weighted graph Merges: [ 3 4 1 2 0 5 7 8 6 9 ] Modularity: ( -0.196145 -0.0895692 -0.0147392 0.146259 0.122449 0 ) Membership: ( 0 1 1 2 2 0 ) Isolated vertices Merges: Modularity: ( NaN ) Membership: ( 0 1 2 3 4 )