Force-Transfer: A New Approach to Removing Overlapping Nodes in Graph Layout

Graphs where each node includes an amount of text are often used in applications. A typical example of such graphs is UML diagrams used in CASE tools. To make text information in each node readable in displaying such graphs, it is required there should be no overlapping nodes. This paper proposes the Force-Transfer algorithm to give a new efficient approach to removing overlapping nodes. The proposed approach employs a heuristic method to approximate the global optimal adjustment with the local minimal movement. Scanning from the seed node, the approach orthogonally transfers the minimum forces to onlythose nodes recursively overlapping with the node from where the forces start. We compare the Force-Transfer with the Force-Scan algorithm by mathematical proofs and experiments. The Force-Transfer approach can generate better results.