Visualizing Changes
of Hierarchical Data using Treemaps
Visualizing Changes
of Hierarchical Data using Treemaps
Abstract
While the treemap is a popular method for visualizing hierarchical data, it is often difficult for the users to track layout and attribute changes when the data evolve over time. When viewing the Treemaps side by side or back and forth, there exist several problems that can prevent the viewers from performing effective comparisons. Those problems include abrupt layout changes, a lack of prominent visual patterns to represent the layouts, and a lack of direct contrast to highlight data differences.
In this paper, we present strategies to visualize changes of hierarchical data using Treemaps. A new treemap layout algorithm is presented to reduce abrupt layout changes and produce consistent visual patterns. Techniques are proposed to effectively visualize the difference and contrast between two treemap snapshots in terms of the map items’ colors, sizes, and positions. Experimental data show that our algorithm can achieve a good balance in maintaining a treemap’s stability, continuity,
Visualizing Changes of Hierarchical Data using Treemaps
IEEE Symposium on Information Visualization (InfoVis’07)
also a special issue of IEEE Transactions on Visualization and Computer Graphics
Ying Tu and Han-Wei Shen
Publication
readability, and average aspect ratio. A software tool is created to compare treemaps and generate the visualizations. User studies show that the users can better understand the changes in the hierarchy and layout, and more quickly notice the color and size differences using our method.
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The Ohio State University, Department of Computer Science and Engineering
395 Dreese Lab, 2015 Neil Avenue, Columbus OH 43210
Professor Han-Wei Shen
hwshen@cse.ohio-state.edu (V) 614 292 0060 (F) 614 2922911