R help - Sep 2007 - Origin label in lattice

I would like to make what seems like a simple addition to a display
constructed from a call to levelplot -- I want to add a text label
(which will, in general, depend on the object being plotted, and so
cannot be hardcoded) to the origin, which has special significance in
my problem.  The x and y axes always have range (0,1) in my plots, so
by "origin" I always mean the lower left corner of the plot.  Now, I
can add text to the inside of the panel using panel.text, but this
clutters the plot and I find it unsatisfactory.  What I would like is
to add the label outside of the panel, just below and to the left of
the lower left corner of the panel.  I've unsuccessfully tried to do
this using the xscale.components argument, and I'm having trouble
figuring out which other arguments or functions might be helpful.  I
would greatly appreciate any advice!

Thanks,

Andrew Smith

Georgia Tech
School of Industrial and Systems Engineering

On 9/13/07, Andrew Smith <andrewsmith81 at gmail.com>
wrote:
> I would like to make what seems like a simple addition to a display
> constructed from a call to levelplot -- I want to add a text label
> (which will, in general, depend on the object being plotted, and so
> cannot be hardcoded) to the origin, which has special significance in
> my problem.  The x and y axes always have range (0,1) in my plots, so
> by "origin" I always mean the lower left corner of the plot. 
Now, I
> can add text to the inside of the panel using panel.text, but this
> clutters the plot and I find it unsatisfactory.  What I would like is
> to add the label outside of the panel, just below and to the left of
> the lower left corner of the panel.  I've unsuccessfully tried to do
> this using the xscale.components argument, and I'm having trouble
> figuring out which other arguments or functions might be helpful.  I
> would greatly appreciate any advice!
You can either turn off clipping in panels with

trellis.par.set(clip = list(panel = "off"))

or use the axis function:

levelplot(volcano,
          axis = function(side, ...) {
              axis.default(side, ...)
              if (side == "bottom")
                  panel.text(0, 0, lab = "label", adj = c(1, 1))
          })

(axis gets called once for every side in every panel, so you have to
make sure you do it only for one side.)

-Deepayan