Using One-Dimensional Compaction for Smaller Graph Drawings

We use the technique of one-dimensional compaction as part of two new methods tackling problems in the context of automatic diagram layout: First, a post-processing of the layer-based layout algorithm, also known as Sugiyama layout, and second a placement algorithm for connected components with external extensions. We apply our methods to dataflow diagrams from practical applications and find that the first method significantly reduces the width of left-to-right drawn diagrams. The second method allows to properly arrange disconnected graphs that have hierarchy-crossing edges.