[R] patterned non-random jitter

[Daryl Morris]

Hi,

Is there a function somewhere that does a "patterned" jitter of data?  
I've googled and the problem is that I don't know what to google for.

The setting is in grouped data.  I have plots which overlay jittered 
points on a boxplot.  I simply jitter the "x-value", and the "y-value" 
has no effect.

Scientists I work with frequently show plots made by another software 
where the jitter looks like a bunch smiles stacked on top of each 
other.  The jitter isn't random, but instead depends on the "y-value" 
somehow.

thanks, Daryl
SCHARP, FHCRC, UW Biostatistics