Rank-directed layout of UML class diagrams

UML class diagram layout is an important task in software visualization to enhance people's comprehension about the systems. In this paper, we describe a novel UML class diagram layout algorithm, called rank-directed method, which captures the difference in relationships among classes and stresses significant classes. As a layout algorithm, rank-directed method supports the clustering of classes according to the inherent characteristics of classes. To recognize the significance of classes, we applied PageRank algorithms through abstracting relationships among different classes as the link among web pages. We assume that important classes have more relationships with other classes. To emphasize the important classes, rank-directed method adopts a sub graph layout method based on clustering of classes. We have developed a UML class diagram layout platform to evaluate our method. Our evaluation shows that rank-directed method could effectively recognize the important classes and layout the class diagram with higher readability than traditional layout methods do.