1. VisDB and Pixel Bar Charts Daniel A. Keim et al. ICS 280 Information Visualization Presented by Jeff Ridenour 4/16/02

2. Introduction n Some problems with Standard Representations: n Limited number of attributes may be examined at one time n Limited Number of Instances n Query Specification Problem: Too general or specific, no feedback

3. Information Visualization Techniques: n Data Type to be visualized (1D, 2D, Multi-D, text, hierarchies, etc.) n Visualization Technique (standard 2D/3D, Geometrically Transformed Icon based, dense pixel, stacked) n VisDB is dense pixel, Pixel Bar Charts mix standard and dense pixel.

4. VisDB n Center is Most Relevant, spiraling out n Color also represents relevance n Calculating Relevance Factors, Distance Functions n Coloration of Relevance Factors

5. Types of Display n Basic Visualization n 2D Arrangement n Grouping Arrangements

6. Examples and Implementation n Interactive Data Exploration n Examples n Visualizing Complex Queries n Implementation

7. Pixel Bar Charts n Compared to Regular Bar Charts n Basic Idea of Pixel Bar Charts n Space filling pixel Bar Charts n Multi-Pixel Bar Charts

8. Formal Definition of Pixel Bar Charts n Dividing, Ordering, and Coloring Attributes. n Ordering Constraints ( Dense Display, No-Overlap, Locality, Ordering) n Pixel Placement Algorithm (Complexity O(n logn)

9. Implementation, Application, and Evalutation n Implemented as Java Applet, Interactive Data Analysis n E-commerce example n Comparison of Parallel Coordinate, Generalized Spiral (VisDB) and Pixel Bar Chart Techniques.