Treemaps were created by Ben Shneiderman in 1990-91 to facilitate information
visualization of hierarchical data sets, such as directory
structures on disks, organizational budgets, and stock
market data. The first implementation at the University
of Maryland Human-Computer Interaction Lab was by
Brian Johnson, whose TreeViz program was built for
the Macintosh in 1991-94. Other implementations were
done by David Turo and Marko Teittinen. The Treemap97
program was written in Delphi by Jerome Brown and
Shaun Gittens.
Dynamic queries enable users to manipulate treemaps
by using slider controls to selectively gray out and
possibly hide nodes of the tree. This supports data
exploration and facilitates location of extreme values
and useful patterns. Treemap 2000 is a Java implementation
of Treemap97 and includes dynamic queries.
In June 2001, Treemap 2000 was replaced by an
improved implementation called Treemap
3.0
My three-month project can be divided into three parts:
1) The research and development of Treemap 97.
2) Implementation of the data structure and the GUI
required for Treemap 2000.
3) Investigation and implementation of double sliders
required for visualization of dynamic queries and
filtering of data using these visual widgets, while
maintaining the integrity of the project.
The final step was the most novel aspect of this project
and an addendum
to Treemap 2000. This step distinguishes Treemap 97
from Treemap 2000.
The work was conducted at the Human Computer Interaction
Laboratory at
the University of Maryland. The Treemap 2000 will
be integrated with StarDOM,
which is another visualization software developed
at University of Maryland.