[R] R task views graph representation

[paul sorenson]

I created a graph of the R task views using python to scrape the HTML, 
networkx to construct the graph at runtime then dumped it out as a 
graphviz dot file.  Finally creating an SVG file with dot:

see http://metrak.com/R/taskview.svg

I was wondering what people find useful for visualising graphs with many 
nodes.   I notice the task views mention igraph and Rgraphviz for 
visualising large graphs.  I haven't tried igraph yet (I need to first 
dump the output of my python script into something that I can import 
with R) but the current SVG is the product of graphviz (dot) so I 
imagine Rgraphviz would yield similar results.

I guess with so many nodes even the "best" layout is going to be pretty 
difficult to read so maybe an interactive method is required?  Having 
said that, if I could add jitter to the rank to get the output 
approaching a square that might help.

My HTML scraping choked on quite a few "nodes" that are apparently 
formatted a bit differently to most of the others so the SVG file is not 
complete.

I just happened to choose the task views as an exercise in dealing with 
graphs, I don't have a particular use of the output in mind.

cheers