Treemaps and the Visual Comparison of Hierarchical Multi-Attribute Data

Treemaps have the desirable property of presenting overviews along with details of data and thus are of interest in visualizations of multi-attribute tabular data with attribute hierarchies. However, the original treemap algorithms and most subsequent variations are hampered in making parallel structures in a hierarchical data structure visually comparable. Structurally parallel elements are not aligned, making it difficult to compare them visually. We propose a method that allows for proportional and non-proportional subdivisions of subtrees while preserving visual alignment of parallel structures. We extend the framework so that other types of data visualizations can be placed within the graphical areas of a treemap to allow for the visual comparison of a broad collection of data types including temporal data.