Dynasty
From Dyna
Dynasty is our graphical interface for browsing large (possibly infinite) directed graphs and hypergraphs. The target graph may change dynamically: it is a graph object maintained by some application.
In particular, a Dyna chart with backpointers -- a proof forest -- can be wrapped up as a hypergraph and browsed using Dynasty. Thus, Dynasty will be the core of the forthcoming Dyna debugger.
Distinctive Features
A Dyna chart may be huge or infinite. Dynasty shows only a small local subgraph around the cursor. This visible subgraph is constantly changing under multiple asynchronous influences:
- user navigation (or search) that brings new nodes into view
- dynamic relayout
- animation
- user operations such as selection, contraction and coloring
- the application's changes to the full underlying graph.
Most dynamic graph explorers do force-directed layout (spring models) of undirected graphs. Dynasty is different in that its Sugiyama-style layouts strongly emphasize the directional flow along edges. For example, in a parse tree or a proof tree, one wants parents to always be above their children. The order of siblings can also be semantically meaningful.
Another novel aspect of Dynasty is that it tries to make keyboard navigation usable. Even small subgraphs can contain tangles, so the arrow keys -- interpreted topologically -- are very helpful in finding related nodes and tracing paths through the graph. The design challenge is that "up" has to choose among many parents, and "left" has to choose among many siblings and mates. Our current solution required considerable experimentation and redesign. We find it interesting and usable, and would appreciate feedback.
Where to Learn More
We will be posting a video shortly! Here is a temporary screenshot.
Eisner et al. (2006) is a short paper about Dynasty, from InfoVis'06. You can also find a nice visual poster at that link with diagrams and details.
If you are interested in using the project or participating in it, or want to see a rough video now, please go ahead and contact us. A public source release is planned for early 2007; we can put your name on the announcement list.
Developers
Existing developers can examine the repository with:
- svn ls svn+ssh://kvetch.cs.jhu.edu/export/dynasty-svn/
