I'm having trouble figuring out how to format Date variables when used as
axis labels in graphs.
The particular case here is an attempt to re-create Nightingale's coxcomb
graph with ggplot2,
where I'd like the months to be labeled as "Mar 1885", "Apr 1885", using a
date format
of "%b %Y" applied to label the dates, or really anything other than
"1885-03-01". I know the solution has to do with formatting the dates, while
preserving their
status as an ordered factor, but I don't know how to do that.