Decluttering Network Graphs
Thu Nov 14, 2013
A problem that many of the co-citation graphs I discussed in the last post share is that they are too dense to be easily readable. I created the sliders as a way of alleviating this problem, but some of the data sets are too dense at any citation-threshold. Being able to view only one of the communities at a time seemed like a plausible solution, but I was far from sure how to implement it using d3.js. Solutions that involved pre-processing the data the way that I did for the sliders didn’t seem to be very useful for this problem.
As I should have realized, making this minor adjustment was far from easy. I eventually realized that I had to change the selection code from the DOM element “circle.node” to just the general grouping element “g.” With a few other tweaks to the force-layout settings, I tested it out with one citation graph that wasn’t too cluttered (compare here). By far the worst graph I’ve created for illegibility has been the philosophy of science one (see also here for an earlier attempt to make it more legible by adding a chronological slider).
Despite my best efforts, these floating balloons of philosophy of science aren’t a great improvement. Labeling the initial beach balls with the centroid node is probably a good idea, along with just some explanatory text. I do think a similar approach is the way forward with this particular technology for visualizing citation graphs. D3.js is very flexible and powerful, particularly in its ability to create and record illustrative animations. I hope to be able to do some more detailed work with it on citation graphs after the semester ends.