Lecture 18:Visualizing Hierarchies April 16, 2013 COMP 150-2Visualization
Admin Events yesterday Color choices -- Color brewer, http://colorschemedesigner.com/ Vis design suggestion: Overview first, (zoom and) filter, details on demand The use of Bar vs. Pie Scalability (in visualization, in scenarios, and in data architecture) Project Due Date Liz office hour moved from 12:30 to 5pm on Friday.
Visualization Tour • Hierarchies (node-link) • Hierarchies (space-filling) • Time-Series • Network and Graphs • Multi-Dimensional Data
Class Exercise • Space-Filling Hierarchies • Node-Link Hierarchies • Combinations of both? • Remember: anytime you can think of a design based on Cartesian coordinate system, there is one corresponding one in Polar coordinate.
Types of Hierarchy Visualizations • Space Filling • Node-Link
Compared to Node-Link • Advantages • Known-size = control of clutter • Structure allows for easy comparison • Additional “visualizations” can be placed within the cells • Disadvantages: • Downside -> harder to see relationships (clusters)? • Can you see a perfect binary tree? • Borders may be necessary -> eats up more pixels than a line (in node-link)
Problems with Squarified • Small change to data / screen aspect ratio -> drastic layout changes • Order independent
Three Solutions • Angular Detail • Detail Outside • Detail Inside
Overview • Turns out that there are TONS more! • IEEE InfoVis 2010, Best Poster Award: “A Visual Survey of Tree Visualization” • http://vcg.informatik.uni-rostock.de/~hs162/treeposter/poster.html