[R] Boxplot, formula interface, and labels.

[Ed Siefker]

I have data I'd like to plot using the formula interface to boxplot.
I call boxplot like so:

with(mydata, boxplot(count ~ geno * tissue))

I get a boxplot with x axis labels like "wt.kidney".  I would like
to change the '.' to a newline.  Where is this separator configured?

Thanks,
-Ed