## Section: Software

### The InfoVis Toolkit

Participant : Jean-Daniel Fekete [ correspondant ] .

The InfoVis Toolkit [3] is an Interactive Graphics Toolkit written in Java to facilitate the development of Information Visualization applications and components.

The main characteristics of the InfoVis Toolkit are:

- Unified data structure
The base data structure is a table of columns. Columns contain objects of homogeneous types, such as integers or strings. Trees and Graphs are derived from Tables.

- Small memory footprint
Using homogeneous columns instead of compound types dramatically reduces the memory required to store large tables, trees or graphs, and usually also the time required to manage them.

- Unified set of interactive components
Interactive filtering (a.k.a. dynamic queries) can be performed with the same control objects and components regardless of the data structure, simplifying the reuse of existing components and the design of generic ones.

- Fast
The InfoVis Toolkit can use accelerated graphics provided by Agile2D(http://www.cs.umd.edu/hcil/agile2d ), an implementation of Java2D based on the OpenGL API for hardware accelerated graphics [23] . On machines with hardware acceleration, some visualizations redisplay 100 times faster than with the standard Java2D implementation.

- Extensible
The InfoVis Toolkit is meant to incorporate new information visualization techniques and is distributed with the full source and a very liberal license. It can be used for student projects, research projects or commercial products.

The InfoVis Toolkit, as of version 0.9, implements nine types of visualization (Fig. 1 ): Time Series, Scatter Plots, Parallel Coordinates and Matrices for tables, Node-Link diagrams, Icicle trees and Treemaps for trees, Adjacency Matrices and Node-Link diagrams (with several layouts) for graphs.

The InfoVis toolkit is used for teaching the Information Visualization course (Masters level, Univ. of Paris-Sud) and is the basis for all AVIZ contracts. It is our main development platform for information visualization; most of our Information Visualization prototypes rely on it. It is available at http://ivtk.sourceforge.net .