R help - Dec 2008 - Lattice trellis.focus() with pdf

Hi,

I have a the code for a plot that works perfectly running in R and  
printing to a Quartz object but which doesn't work when I make the  
trellis device a pdf.

The code is as follows:
----

trellis.device(device="pdf", new=TRUE)
trellis.par.set(my.theme())
dotplot(Y ~ X | C, groups=G, data=D, layout=c(2,1), ... )

trellis.focus("panel", 1, 1)
for (y in 1:5) {
	panel.segments(...)
}
trellis.unfocus()

trellis.focus("panel", 2, 1)
for (y in 6:10) {
	panel.segments(...)
}
trellis.unfocus()

dev.off()

----

The first for loop draws perfectly but the next panel never takes the  
focus and doesn't draw anything.  The resulting file has the red focus  
box around the first panel still when the commands finish.  Again,  
everything is fine when the device is a Quartz object.

- Chris

Chris Poliquin <poliquin <at> sas.upenn.edu> writes:
> 
> Hi,
> 
> I have a the code for a plot that works perfectly running in R and  
> printing to a Quartz object but which doesn't work when I make the  
> trellis device a pdf.
> 

  Is this FAQ 7.22
http://cran.r-project.org/doc/FAQ/R-FAQ.html#Why-do-lattice_002ftrellis-graphics-not-work_003f

?

  (I'm not sure it is, but it might be)

  Ben Bolker

On Wed, Dec 31, 2008 at 3:41 PM, Chris Poliquin <poliquin at
sas.upenn.edu> wrote:
> Hi,
>
> I have a the code for a plot that works perfectly running in R and printing
> to a Quartz object but which doesn't work when I make the trellis
device a
> pdf.
>
> The code is as follows:
> ----
>
> trellis.device(device="pdf", new=TRUE)
> trellis.par.set(my.theme())
> dotplot(Y ~ X | C, groups=G, data=D, layout=c(2,1), ... )
>
> trellis.focus("panel", 1, 1)
> for (y in 1:5) {
>        panel.segments(...)
> }
> trellis.unfocus()
>
> trellis.focus("panel", 2, 1)
> for (y in 6:10) {
>        panel.segments(...)
> }
> trellis.unfocus()
>
> dev.off()
>
> ----
>
> The first for loop draws perfectly but the next panel never takes the focus
> and doesn't draw anything.  The resulting file has the red focus box
around
> the first panel still when the commands finish.
Look more closely at your PDF file; it has more than one page.

"Removing" graphical objects in grid (the red box in this case) has
the effect of redrawing everything else in a new page. To avoid new
pages, you need to avoid such removal, which in this case is as easy
as

trellis.focus("panel", 1, 1, highlight = FALSE)

etc.

-Deepayan