[R-sig-ME] Plotting Grouped Data

[Murray Jorgensen]

plot() works nicely with the data sets that come with nlme, so 
presumably there is a plot.something() that is well set up to plot data 
with grouping factors.

Now how can I get my data sets into "something" form so that I may use 
plot.something() or, alternatively, what is "something" so that I may 
hack plot.something() to work with my data as it is?

Cheers,  Murray Jorgensen