Generating customized layouts automatically

Abstract

Most existing automatic layout techniques are designed to generate layouts that look pleasant to the eye by improving aesthetics of graphs. Aesthetics, however, do not reflect layout requirements derived from semantics, preference or individual situations. It is important for an automatic layout technique to generate customized layouts according to specific requirements given by the user or applications. This thesis investigates how to generate customized layouts using selected layout algorithms. A key to this problem is to improve the expressive power of existing algorithms and integrate different techniques to deal with various layout requirements. LYCA is a graph tool that uses incremental optimization algorithms to draw directed and undirected graphs. It integrates a constraint solver to process constraints. Compared with other works, LYCA has several distinctive features: The force-directed placement algorithm is improved to generate compact layouts for graphs with large vertices.; A novel usage of the divide-and-conquer approach is introduced to generated structured layouts.; The constraint solver and the layout algorithms are integrated in a simple and efficient way. In addition, the solver and layout algorithms cooperate to ensure layout quality.; Different interface techniques are used to help the user diagnose layout problems and interact with the layout algorithms directly. Those features provide a tight coupling of the user and the layout tool. Users can generate customized layouts with LYCA easily and flexibly.