Orthogonal graph visualization: the three-phase method with applications

In this dissertation, we study automated graph visualization in the orthogonal style. Our core idea is to break the problem of generating an orthogonal drawing into three phases: first placing the nodes as points, then approximately routing the edges, and finally converting nodes to boxes and assigning edges to ports at nodes. With different implementations of the phases, this scheme yields a wide range of results. We obtain drawings which improve on previously known results in terms of the area and the number of bends, and study drawings of planar graphs and of complete graphs. Breaking the drawing generation into three phases results in a highly flexible algorithm, which permits to add various additional requirements, such as constraints on the placement of nodes, the size of nodes, and the assignment of ports. This study of orthogonal visualization algorithms was initiated by the need to add an orthogonal library to a commercially available layout toolkit, and major parts of this thesis have been implemented as part of this toolkit.