Fig. 7

A real example of a pair of overlapped communities detected by PCMA. The overlap is a single vertex colored half purple and half red. The outbound edges from the left (right) community to the right (left) are all through the overlapped vertex (category E1), except for one edge that interconnects the two communities directly (category E2). Since an E2 outbound edge of a community is also an E2 outbound edge of the corresponding neighbor community, we adopt a simplified term that the edge is an E2 edge of the overlap. Most overlaps are like those in this example, having only one vertex and very few E2 edges, making the corresponding pair of communities well separated from each other