R help - Apr 2006 - panel.abline() and trellis.focus() on multipage plots

Hi,

I'm recently working on a multipage bwplot() using the lattice package. In
this context I was trying to use the panel.abline() function individually on
certain panels but not all. After some research I found the trellis.focus()
and trellis.unfocus() functions which enabled me to do something like:

     trellis.focus("panel", 1, 3)
        do.call("panel.abline", list (c(0.5, 0),
col="tomato", lty=2 ))
     trellis.unfocus()

The result is quite what I expected and working properly as long I'm having
a one-page plot. It happens quite frequently though, that I'm operating with
multipage plots. In this case I'm only able to manipulate the panels of the
last page which I find quite unfortunate.

So here's my question now:

Is there any chance of using trellis methods to solve this problem or is it
necessary to dive into the deep realms of the grid package do this? Would it
make any difference if I pass the result of my bwplot() call to a trellis
object and manipulate this before plotting?

with kind regards

Vincent

	[[alternative HTML version deleted]]

On 4/13/06, vincent david <vega42 at googlemail.com>
wrote:
> Hi,
>
> I'm recently working on a multipage bwplot() using the lattice package.
In
> this context I was trying to use the panel.abline() function individually
on
> certain panels but not all. After some research I found the trellis.focus()
> and trellis.unfocus() functions which enabled me to do something like:
>
>      trellis.focus("panel", 1, 3)
>         do.call("panel.abline", list (c(0.5, 0),
col="tomato", lty=2 ))
>      trellis.unfocus()
>
> The result is quite what I expected and working properly as long I'm
having
> a one-page plot. It happens quite frequently though, that I'm operating
with
> multipage plots. In this case I'm only able to manipulate the panels of
the
> last page which I find quite unfortunate.
>
> So here's my question now:
>
> Is there any chance of using trellis methods to solve this problem or is it
> necessary to dive into the deep realms of the grid package do this? Would
it
> make any difference if I pass the result of my bwplot() call to a trellis
> object and manipulate this before plotting?
If the determination of which panels need this enhancement can be done
algorithmically, you can code that into your panel function (the
'panel.number' argument can help). Trellis objects can be subsetted,
so you can print one page at a time.

Deepayan