R help - Oct 2006 - Adding per-panel text to panel strips in lattice xyplot

I would like to add auxiliary information to the bottom of two strips on 
each panel that comes from a table look-up using the values of two 
variables that define the panel.  For example I might panel on sex and 
race, showing 3 randomly chosen time series in each panel and want to 
add (n=100) in the bottom strip to indicate the 3 curves were sampled 
from 100.  Is there a not-too-hard way to do that?

I would like to do this both with and without groups= and superposition, 
but especially with.

Thanks
Frank
-- 
Frank E Harrell Jr   Professor and Chair           School of Medicine
                      Department of Biostatistics   Vanderbilt University

Take a look at the xysplom function in package HH.
You can use it as a model for what you want.

tmp <- data.frame(x=rnorm(24),
                  y=rnorm(24),
                  a=factor(rep(letters[1:2],12)),
                  b=factor(rep(LETTERS[1:3], c(8,8,8))))
xysplom(y ~ x | a*b, data=tmp, corr=TRUE, layout=c(2,3))
 
The work is done with the cooperation of two functions.

xysplom.default looks for the corr argument and then creates
an additional conditioning factor and gives it a constant value.

strip.xysplom sees where it is and changes the strip label as needed.

strip.xysplom uses the R-2.3.1 technology for finding where it is.
Deepayan added some more functions in R-2.4.1, so that part of
the code can now be somewhat simplified.

lattice in R-2.4.0 also has a new strip.left argument (see ?xyplot and
serach for strip.left) that will allow you to put the additional
information in an additional left strip for each panel, rather than by making
changes to one of the standard top strips.

Rich

On 10/13/06, Frank E Harrell Jr <f.harrell at vanderbilt.edu>
wrote:
> I would like to add auxiliary information to the bottom of two strips on
> each panel that comes from a table look-up using the values of two
> variables that define the panel.  For example I might panel on sex and
> race, showing 3 randomly chosen time series in each panel and want to
> add (n=100) in the bottom strip to indicate the 3 curves were sampled
> from 100.  Is there a not-too-hard way to do that?
>
> I would like to do this both with and without groups= and superposition,
> but especially with.
There might be, but it might be easier with some changes to lattice.
Can you give a minimal example so that we can try out ideas?

Deepayan

This looks like an application for bottom.strips and right.strips,
in addition to the current left.strips and strips, in each panel.
The new feature is that these new strips might be associated with
different information than the regular strips that reflect
the levels of the conditioning variables.