For visualizing hierarchical structures, such as organizational structures and computer networks, arranging nodes at the same level horizontally is challenging because this results in an extremely wide diagram and underutilizes large portions of the drawing area. Researchers from the University of Tsukuba have developed a layout method that circumvents this issue by positioning nodes at the same level along a folded line. This approach allows for the efficient organization of hierarchical structures within a drawing area with a specified aspect ratio.

Tsukuba, Japan—Hierarchical structures, including organizational structures and computer networks, are mathematically represented as "rooted trees" that connect related nodes with edges. These can be visualized as a diagram for easier understanding of the hierarchical structure. However, traditional visualization methods tend to produce diagrams that are disproportionately wide. Moreover, the size of the diagram may be considerably diminished depending on the aspect ratio of the drawing area, leading to a substantial amount of space being wasted.

To address this problem, the current study developed a layout method that modifies the traditional requirement of horizontally aligning nodes at the same level. This method maintains the "monotone" condition of visually arranging the parent-child relationship in a hierarchical top-down structure. This method is termed as the monotone local folding layout, in which nodes of the same level are placed along a folded (occasionally vertical) line rather than a horizontal line. Applying this method to visualize a computer network comprising switches and many terminals in a large organization with a conventional hierarchical layout results in an extremely wide diagram. However, the monotone local folding layout enables the creation of a network diagram that efficiently occupies the available space within the aspect ratio of the drawing area.

Original Paper

Title of original paper:

Area-adaptive Drawing of Rooted Trees

Journal:

IEEE 17th Pacific Visualization Conference (PacificVis 2024)

Correspondence

Professor MISUE Kazuo
Institute of Systems and Information Engineering, University of Tsukuba

Related Link

Institute of Systems and Information Engineering