I help people communicate data clearly with graphs. I recently saw the infographic ... the center of cities using their subway systems. Overlapping symbols show that you can get from one city ...

For example, consider graphs like this: I just coded this algorithm out in ruby, what fun that was.... So after you've labeled your nodes instead of picking one and moving on, you just arbitrarily ...

In the second step, we quantify the extent of overlap between each pair of groups ... To illustrate the above procedure, let us consider an example graph with 11 nodes, seven of which are marked ...