Abstract:

The spring-electrical model based force directed algorithm is widely used for drawing undirected graphs, and sophisticated implementations can be very efficient for visualizing large graphs. However, our practical experience shows that in many cases, layout quality suffers as a result of non-uniform density. This gives rise to warping effects in that vertices at the outskirt of the drawing are often closer to each other than those near the center, and branches in a tree-like graph tend to cling together. In this paper we propose algorithms that overcome these effects. The algorithms combine the efficiency and good global structure of the spring-electrical model, with the flexibility of the stress model in specifying an ideal edge length, and are very effective and efficient in overcoming the warping effects.