Gephi at SISC’09 (3rd French Symposium on Complex Systems)

The Gephi team will present a poster at SISC’09, 3rd French Symposium on Complex Systems. The conference is set for November 25 – 27 in Paris, France. This is the first time we present the whole work of the community on Gephi 0.7.

pdf Poster: Gephi 0.7 project: Modular architecture for a large graph visualization and manipulation software – Building a modern and durable open-source project

Version 0.7 launched

I’m pleased to inform the community that we are working on a new Gephi core. As it is explained in recent news about 0.6 beta2 release, we won’t publish an official 0.6 version and move directly to an entire new architecture. Though the 0.6 architecture is pretty stable and has been used for worth case studies (see our Exhibition section or WebAtlas gallery), it doesn’t fit with various new needs, like clustering support and complete dynamic network (DNA) support. The 0.6 core was used since September 2007 from now, mostly in an experimental context. As we receive many positive comments and support, we are adopting a long term view and enter a new development cycle. When increasing quality and modularity of the application, we expect more developers helping and a lower learning curve. Therefore the new architecture will be based on the awesome Netbeans Platform, currently the most advanced open-source framework for large Java modular applications. Plugins development will be eased when based on this framework.

Besides the framework, the most serious change will be located in data structures, with a brand new technology. Developed by us for more than 6 months, the DHNS (Durable Hierarchical Network Structure) is a very efficient data structure for storing hierarchical and dynamic networks. Thanks to this new module, new hard features like a clustering algorithm framework or hierarchical network navigation could be hatched more easily. I am currently writing a paper about these researches.

Other features will be added or improved within 0.7 version, you can have a look on our 2009 roadmap. It’s hard to say now exactly how priorities will be managed but I will publish regularly news about the progress for keeping you informed. For now the top priority is building the new architecture around Netbeans Platform.

Until the end of summer, Gephi project is hosted by RTGI SAS in Paris. Besides supporting our project, they plan to use Gephi daily and thus we have feedbacks and opportunities improving user interface and ergonomics.

Let’s go back to work and build the best open-source network visualization software.

Nodes groups visualization

Loic Fricoteaux, student in Computer Science worked on a Gephi research project about visual representation of nodes groups. Next big move of Gephi will be supporting clustering and hierarchy navigation. Thus this project helps to keep network readibility within cluster exploration. We expect presence of this functionality for the first 0.7 release, later this year.

Implicit surface system on a sample graph
Implicit surface system on a sample graph

The purpose of this module is to enable users to highlight nodes groups in a graph, providing a better visibility for them. For instance, it can be useful to reveal/highlight patterns or just to highlight meaningful nodes aggregates in a network.

To visually represent nodes groups, each node of a group has a circular (by default) influence area which decreases as long as the distance from the associated node increases. A thresholding of the summation of all these influence areas defines a surface (not necessary connected) enclosing every nodes in a smoothness manner. The final rendering can be hugely parameterized to match user preferences (size of influence areas, color, antialiasing, …).

Computing surface

In order to allow a real-time rendering for many nodes groups in big dynamic graphs, an optimized algorithm has been specifically developed to fill the corresponding enclosing surfaces while keeping a handsome rendering.