WIP: optionally output graph in pajek format

[bluegenes]

In cluster, we use connected_components to output a set of clusters. However, there are a number of other community detection algorithms we might be interested in using.

By outputting the network graph, we can read the raw graph into another program (networkx/igraph) and use community detection (e.g. igraph.community_infomap). This would be an alternative to using the connected_components clusters.

[szhorvat]

If you are interested in interop with igraph, I recommend GraphML or GML, both of which have clear specifications and are intended for general purpose graph storage and exchange. At igraph, our goal with the Pajek reader/writer is interop specifically with the Pajek software, not with other systems.

[ctb]

If you are interested in interop with igraph, I recommend GraphML or GML, both of which have clear specifications and are intended for general purpose graph storage and exchange. At igraph, our goal with the Pajek reader/writer is interop specifically with the Pajek software, not with other systems.

cool! I've had some small experience with GML in spacegraphcats, it's pretty straightforward to emit.