Retrieves US House and Senate data from Wikipedia, then makes parliament diagrams for each.
This set of R code was originally intended to demonstrate RVest but grew into a useful set of code that makes Parliament Diagrams, after the ones I saw on Wikipedia weren't particularly uniform or easy to keep current (though see this XKCD comic for why I'm tilting at windmills).
It handles small numbers of parties pretty well. Larger numbers of parties are less elegantly handled and are hard to keep contiguous, but I have made some improvements that help in recent revisions. It also provides more customizability than other scripts I have seen, though the computational geometry is no more robust or elegant than other examples I've seen.