1. Dynamic Queries cs5984: Information Visualization Chris North

2. Assignment Read for Tues: Roth, “Visage”, web (video) » josh, priya North, “Snap-Together Visualization”, web Multiple Views

3. Assignment Read for Thurs Plaisant, “Lifelines”, p 285 » chris r., margaret Mackinlay, “Perspective Wall”, web » sumithra, gowri Read for nextnext tues Eick, “SeeSoft”, p 419 » purvi, prasuna Eick, “Data Visualization Sliders”, p 251 (2 pages) Homework #1 due Monday 5pm

4. HomeFinder

5. Spotfire

6. Limitations Scale: Scatterplot screen space: 10,000 – 1,000,000 Data structures & algorithms: 50,000 – 1,000,000 –Poor screen drawing on Filter out A Solution: Query Previews! AND queries only Arbitrary boolean queries? A solution: Filter Flow Another solution: Magic Lens

7. DQ Algorithm Idea: incremental algorithm, only deal with data items that change state When slider moves: Calculate slider delta Search in data structure for data items in the delta region If slider moved inward (filter out): –Erase data items from visualization Else (filter in): –Draw data items on visualization Problem! Overlapped items, erases items underneath too

8. DQ Data Structures Sorted array of the data for each slider Need counter for each data item = # sliders that filter it Multi-dimensional data structure E.g.: K-d tree Recursively split space Enables fast range search

9. Filter-Flow

10. Today Fishkin, “Movable filters” (Magic Lens), p253 » prasuna, umer Doan, “Query Previews”, web page » aarthi, ameya

11. Review Many attributes: Many items: Very Many items: Hard! Why? Can’t show everything, interaction is key