Complex software systems are often modeled using data flow diagrams, in which nodes are connected to each other through dedicated connection points called ports. The influence a layout algorithm has on the placement of ports is determined by port constraints defined on the corresponding node. In this paper we present approaches for integrating port constraints into the layer-based approach to g...

Many systems in the modern world are readily represented as graphs; with nodes representing objects within the system, and edges the relationships between them. The effectiveness of visualisations of complex systems is often dependent on the layout of their graphs; a good layout can provide ready understanding of complexity, while a poor layout does nothing to aid comprehension and can even obs...

Constraints have played an important role in the construction of GUIs, where they are mainly used to define the layout of the widgets. Resizing behavior is very important in GUIs because areas have domain specific parameters such as form the resizing of windows. If linear objective function is used and window is resized then error is not distributed equally. To distribute the error equally, a q...

We present branch-and-bound algorithms for nding a maximum planar subgraph of a nonplanar graph. The problem has important applications in circuit layout, automated graph drawing, and facility layout. The algorithms described utilize heuristics to obtain an initial lower bound for the size of a maximum planar subgraph, then apply a sequence of fast preliminary tests for planarity to eliminate i...

Directed and undirected graphs provide a natural notation for describing many fundamental structures of computer science. Unfortunately, graphs are hard to draw in an easy to read fashion. Traditional graph layout algorithms have focused on creating good layouts for the entire graph. This approach works well with smaller graphs, but often cannot produce readable layouts for large graphs. This p...

This thesis describes a way to visualize hierarchical structures on PDAs using Treemaps. A new ordered layout algorithm for treemaps, called Split Layout, is presented. Traditionally, treemap algorithms have exhibited a trade off between good aspect ratio and ordered layout. The new Split Layout is compared to five published treemap algorithms. Properties such as avarage aspect ratio, stability...

Graph drawing algorithms have important practical applications, e. g. layer-based algorithms for data flow diagram layout in embedded software design and planarization-based algorithms to layout UML diagrams in software engineering. Most current drawing methods focus on the optimization of aesthetic criteria such as the number of edge crossings and bends. The aspects of compactness and aspect r...