This article discusses graph file format and introduce a new support page about graph import, which explain a bit of each format and gives tips about current Importer’s specificities.
Gephi supports major graph file format and GEXF, which is our own creation. These file format come from different editors and therefore none is really a standard. Needless to say Gephi supports them for enable previous work to be imported but it is not always easy, due to differences between them. Some standardization efforts exist but they are difficult to apply anyway, due to very different features within graph editors, for instance mixed diagrams and graphs editors.
Our approach when building the GEXF format is slightly different. Instead being specific to our software focus is made on what may be common to all network editors. In addition it will be the first standard dynamic, yet easy format. You can follow the process of specification and see some samples on this page. It recently reached a 1.1 version.
Gephi’s domain of application are networks only, this tends to clarify which data shall be imported. Although these (old) formats can have sometimes complicated functionalities, only few are essential to import a graph structure in Gephi, in sum topology and attributes.
See below current and future status about file import. Note that graph file format export is so far not a priority, as long as we have GEXF export, but we may perhaps consider it more in the future. Note that as PDF is not a graph format, export feature is set at high priority for 0.7.
Import Implementation status (Gephi 0.6 beta2)
|* GEXF||Implement GEXF 1.0 Specification.|
|* GDF||Implemented, but some rare bugs remains.|
|* GraphML||Support basic node, edge and attribute. Don’t currently support hierarchy but planned for 0.7.|
|* Pajek||Implemented, works fine.|
|* XGMML||As for GraphML, hierarchy is not yet supported.|
More details and compare on Supported Graph Formats.
|* GML||Needs to be done, planned for 0.7 version.|
|* Excel/CSV||We are thinking how to do this.|
|* Database||In the 2009 roadmap.|