ANGULAR TREEMAPS - Information Visualisation: Techniques, Usability and Evaluation - page 97

time to obtain the context view. Positions of all vertices in a sub-tree are
recalculated each time a user uses “zoom in” or “zoom out”. For instance,
in Fig 5.10 (a) and (b), when a focus view is selected by a mouse-click, the
selected sub-structure expands to the entire display area (see Fig. 5.10 (c)).
Based on the weighted Divide and Conquer algorithm, the Angular
Treemaps application provides either a non-rectangular layout or a mixture
of rectangular and non-rectangular layouts in short computational time. A
system implemented with data mining methods can generate a layout
automatically based on a query, in order to draw a user's attention and
recommend the focus of interests. Also users can use drop box to rotate
particular sections, based on interests as part of a particular task. It can
help a user to track his or her own mental map during exploration, and
compare one object with another. The usability test in the following
section demonstrates that, in real scenarios, Angular Treemaps
successfully enhances information visibility and highlights the focus of
interest by differentiating various sub-hierarchical structure layouts. These
positive results have shown its efficiency and effectiveness in location and
identification tasks.
(a)