[R] boxplot changes fontsize of labels

[Sebastian Merz]

Hi all!

So far I learned some R but finilizing my plots so they look
publishable seems not to be possible.

I set up some boxplots. Everything works well but when I put more then
two of them in one plot the labels of the axes appear smaller than the
normal font size.

> x <- rnorm(30)
> y <- rnorm(30)
> par(mfrow=c(1,4))
> boxplot(x,y, names=c("horray", "hurra"))
> mtext("Jubel", side=1, line=2)

In case I take one or two boxplots this does not happen:
> par(mfrow=c(1,2))
> boxplot(x,y, names=c("horray", "hurra"))
> mtext("Jubel", side=1, line=2)

The cex.axis seems not to be changed, as setting it to 1.0 doesn't
change the behaviour. If cex.axis=1.3 in the first example the font
size used by boxplot and by mtext is about the same. But as I use a
function to draw quite some of these plots this "hack" is not a proper
solution.

I couldn't find anything about this behaviour in the documention or
the inet.

Can anybody explain? All hints are appriciated.

Thanks,
S. Merz