ANGULAR TREEMAPS - Information Visualisation: Techniques, Usability and Evaluation - page 83

C HAPTER F IVE
A NGULAR T REEMAPS
J IE L IANG , Q UANG V INH N GUYEN ,
S IMEON S IMOFF AND M AO L IN H UANG
Abstract
Space-filling visualization techniques have proved their capability in
visualizing large hierarchically structured data. However, most existing
techniques restrict their partitioning process in vertical and horizontal
directions only, which causes problems with identifying hierarchical
structures. This chapter presents a new space-filling method named
Angular Treemaps that relaxes the constraint of the rectangular
subdivision. The approach of Angular Treemaps uses the divide and
conquer paradigm to visualize and emphasize large hierarchical structures
within a compact and limited display area with better interpretability.
Angular Treemaps generate various layouts to highlight hierarchical sub-
structure based on user's preferences or system recommendations. It offers
flexibility to be adopted into a wider range of applications, regarding
different enclosing shapes. Preliminary usability results suggest user's
performance is improved by using this technique in locating and
identifying categorized analysis tasks.
Introduction
Data visualization is the study of the visual representation of data, and
“information that has been abstracted in some schematic form, including
attributes or variables for the units of information” [1]. Most visual
representations are created to assist viewers communicate with information
in order to understand the data in the following three ways: the value of
data , the behaviour of data and the relational structure of data .