Department of Computer Engineering
IMPROVING THE CIRCULAR LAYOUT ALGORITHM FOR CLUSTERED GRAPHS
H. Eren Çalık
(Supervisor: Prof. Dr. Uğur Doğrusöz)
Computer Engineering Department
Data or information visualization is an important and commonly used approach in almost all fields of science and industry. Graph layout is an important part of this field as graph-based data has been increasing immensely. There are different approaches and algorithms to visualize graphs for different types of data. However, for drawing aesthetically pleasing graphs, force-directed layout is the mainly used approach. One such algorithm specifically designed for clustered graphs is a circular layout algorithm named Circular Spring Embedder or CiSE, which uses a modified spring embedder and heuristics to improve the quality of the layout. This algorithm produces high-quality layouts with respect to commonly accepted criteria, in which circles are composed of nodes of the same cluster and behave as individual nodes themselves. Although it produces good layouts, it has limitations, i.e., inefficient use of the room inside the circles and high calculation costs. In this work, an approach to improve the use of inside the circles is proposed and other and further improvements are discussed. In the proposed approach, a smaller circular boundary inside the circle is used to prevent inner nodes from getting out of the cluster circle while the cluster circle's size is increased when a certain threshold based on node numbers and experimental parameters is exceeded. It can be the first step of a multi-level structured circular layout.
DATE: 29 March 2021, Monday @ 15:30