[R] null plotting symbol ?

[Peter Dalgaard BSA]

tblackw at umich.edu writes:

> I am calling  plot()  with argument pch as a vector of numeric 
> symbol codes, the same length as x and y.  Is there some code 
> which produces no symbol - a blank - so that I can come back 
> with a second call to  points()  and fill in these locations 
> using a different fill color and a different symbol size ?  
> 
> There's always a work-around, but both x and y are generated 
> on the fly by calls to  cumsum(),  so it's inconvenient to put 
> NAs into either x or y to suppress plotting that way.  Guess 
> I should *try* mixing numeric and character symbol codes, 
> although the example in  help("points")  explicitly uses a list 
> at that point.  

Doesn't NA work there??

plot(1:10,pch=c(1:4,NA,6:10))

works for me on Linux, but there could be device dependencies.

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907