[R] Add points to subplots

[Jim Lemon]

On Fri, 13 Jun 2014 12:02:34 PM Luca Cerone wrote:
> Thanks David,
> I already did this, but in case the code gets updated I will have to
> re-add the annotation, which I do not think it is ideal.
> 
> I was just wondering if there is an easy solution to this.
> Thanks a lot for the help,
> 
Hi Luca,
I decided to try using the split.screen function, which I had previously 
tried without getting what I wanted. This example:

split.screen(c(2,1))
screen(1)
screen()
plot(1:7)
screen(2)
plot(1:6)
screen(1,FALSE)
screen()
points(x=7:1,y=1:7,col="red")

when run with no graphics devices currently open, seems to work and do 
what you want. When I first tried it on an open device (x11) it would not 
switch screens properly, remaining on the top (first) screen despite calls 
to screen() that reported that the screen had changed. I tried this after 
opening a png device and it also worked correctly, so I think that if you 
are careful to initialize the graphics device immediately before 
split.screen it should do it.

Jim