[igraph] overlapping network communities - plotting & indexing

[tom]

Hi Listers,
I am performing community detection on a fully-connected undirected &
weighted network.
To obtain the communities I  use the OSLOM algorithm, and read these into
R.
OSLOM detects overlapping communities, and produces a membership data frame,
in which each row is a vertex, and each column a community, like this:

A    B    C    D
0    0    0    0
1    1    1    1
0    0    0    1
0    1    1    0
0    0    1    0
0    0    0    0
0    0    0    1

Notice vertex 2 belongs to all 4 communities, and vertices 1 & 6 are
'singletons', belonging to none.

I have 2 questions;
1. I would like to plot this graph & the overlapping communities in the same
manner as the examples given in cohesive.blocks. How ?

2. if there are 3 communities, then there are 8 possible classes;
A,B,C,AB,BC,AC,ABC, & none. So is there a method to index the different
vertices according to the classes, as in the typical igraph community
membership functions?

Thanks!
Tom