Node-link circular layout: Sankey links

Another experiment along the line of this one. This time, links are drawn in a way that the overlap near the node is removed. The method is somehow reminiscent of Sankey diagrams (see this paper for similar considerations, applied to arc diagrams).

Besides reducing visual clutter, two advantages of this design are:

• The size of the "strip" near each node is proportional to the node weighted degree centrality (i.e. the sum of the weights of its links), thus encoding a new important variable "for free".
• The size of each node can thus be used to encode a different quantitative property of the node (usually, it would have been the node degree).