From cbodily@att.net  Thu Sep 26 18:37:42 2002
From: cbodily@att.net (cbodily@att.net)
Date: Thu, 26 Sep 2002 19:37:42 +0200 (MET DST)
Subject: split.screen problem (PR#2069)
Message-ID: <200209261737.TAA21302@pubhealth.ku.dk>

Full_Name: Chris Bodily
Version: 1.5.1
OS: W2K
Submission from: (NULL) (63.106.106.2)


I took the following code directly from the 'split.screen' help page in R and
modified one line to highlight the problem I encountered.  Basically, it appears
that when plotting in split screens and attempting to return to a particular
screen to add or update points, the axes from the original plot are not
remembered, causing the new points to plot incorrectly.
 
A workaround seem to be storing the original plot range and issuing
'plot(x,y,type="n")' where x and y are data vectors with ranges that match the
original plot in the screen of interest.  Then a 'points' command draws in the
correct locations.
 
I found this by moving working code from S-Plus 2000 into R v1.5.1 and noticed
that a particular interactive plot I use began drawing incorrectly.
 
Thanks,
 
Chris Bodily
 
#--------------------------------------------------------------------------------------
 
 
   if (interactive()) {
     par(bg = "white")           # default is likely to be transparent
 
     split.screen(c(2,1))        # split display into two screens
     split.screen(c(1,2),2)      # split bottom half in two
 
     plot(1:10)                  # screen 3 is active, draw plot
     erase.screen()              # forgot label, erase and redraw
     plot(1:10, ylab= "ylab 3")
 
     screen(1)                   # prepare screen 1 for output
     plot(1:10)
 
     screen(4)                   # prepare screen 4 for output
     plot(1:10, ylab="ylab 4")
 
     screen(1, FALSE)            # return to screen 1, but do not clear
#     plot(10:1,axes=FALSE, pch=2,col=5, lty=2, ylab="")  # overlay second plot

## Problem here as the following points get plotted incorrectly ##
## it seems that the axes are reset                             ##
     points(rep(3,10),1:10,col=2,pch=2)  # add a few more points for a test
 
     axis(4)                     # add tic marks to right-hand axis
     title("Plot 1")
     close.screen(all = TRUE)    # exit split-screen mode
     }


-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-devel-request@stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._


split.screen problem (PR#2069)
cbodily@att.net