Converting 2 mode networks with Multimodal plugin for Gephi

Scott Weingart drew my attention this morning to a new plugin for Gephi by Jaroslav Kuchar that converts multimodal networks to one mode networks.

This plugin allows multimode networks projection. For example: you can project your bipartite (2-mode) graph to monopartite (one-mode) graph. The projection/transformation is based on the matrix multiplication approach and allows different types of transformations. Not only bipartite graphs. The limitation is matrix multiplication – large matrix multiplication takes time and memory.

After some playing around, and some emails & tweets with Scott, we determined that it does not seem to work at the moment for directed graphs. But if you’ve got a bimodal undirected graph, it works very well indeed! It does require some massaging though. I assume you can already download and install the plugin.

1. Make sure your initial csv file with your data has a column called ‘type’. Fill that column with ‘undirected’. The plugin doesn’t work correctly with directed graphs.

2. Then, once your csv file is imported, create a new column on the nodes table, call it ‘node-type’ – here you specify what the thing is. Fill it up accordingly. (cheese, crackers, for instance).

3. I thank Scott for talking me through this step. First, save your network; this next step will irrevocably change your data. Click ‘load attributes’. Under attribute type, select your column you created for step 2. Then, for left matrix, select select Cheese – Crackers; for right matrix, select Crackers – Cheese. Hit ‘run’. This gets you a new Cheese-Cheese network (select the inverse to get a crackers – crackers network).  You can then remove any isolates or dangly bits by ticking ‘remove edges’ or ‘remove nodes’ as appropriate.

4. Save your new 1 mode network. Go back to the beginning to create the other 1 mode network.