ANGULAR TREEMAPS - Information Visualisation: Techniques, Usability and Evaluation - page 96

Fig. 5.9. Application demonstration of file systems overview with boundary gaps
feature.
Colour saturation and edge thickness changes are used to assist when
transferring from views of one level to another. For example, from
overview (see Fig. 5.10(a)) to subfolder of “mp3” (see Fig. 5.10(b)) on a
lower level, edges of the lower level nodes are thinner, and the colour of
the lower level nodes are lighter than those of higher level nodes
Navigation and Interaction
A navigation scheme should enable users to adjust views interactively to
reach the final view of a sub-graph, allowing them to obtain optimal
understanding of the data items and surrounding relational structure they
are currently interested in, with minimal navigation steps. Without
interaction mechanisms that let users explore data, capabilities of
visualization tools cannot maximize human capabilities to perceive and
understand complex and dynamic data.
A semantic zooming technique is adopted to assist users in exploring
large hierarchies with detailed viewing. We use zoom in to view the
details of a particular part in the hierarchy and users can zoom out at any