[R] Add points to subplots

[Luca Cerone]

Dear all,
I am running some analysis using the pamr package (available on CRAN).

One of the plots I produce is made using the function "pamr.plotcv".
This displays two plots in the same figure (using par(mfrow=c(2,1)).

When the figure is created, I would like to be able to add some points
and lines, to the top plot.

After producing the plot with pamr.cvplot, I have tried to add a line
doing something like:

par(mfg=c(1,1))
lines(c(3,3), c(0,1), col = "blue", lty = 3)

However this doesn't work and the line is shown in the bottom plot.
How can I add points and lines to the top plot?

Thanks a lot in advance for the help,

Cheers,
Luca