Abstract

This paper describes a local update scheme for the algorithm of Sugiyama and Misue (IEEE Trans. on Systems, Man, and Cybernetics 21 (1991) 876--892) for drawing views of compound graphs. A view is an abstract representation of a compound graph; it is generated by contracting subgraphs into meta nodes. Starting with an initial view, the underlying compound graph is explored by repeatedly expanding or contracting meta nodes. The novelty is a totally local update scheme of the algorithm of Sugiyama and Misue. It is more e#cient than redrawing the graph entirely, because the expensive steps of the algorithm, e. g., level assignment or crossing minimization, are restricted to the modified part of the compound graph. Also, the locality of the updates preserves the user's mental map: nodes not a#ected by the expand or contract operation keep their levels and their relative order; expanded edges take the same course as the corresponding contracted edge.

Citations