R help - Aug 2008 - Jitter in xYplot?

Hello,

The simple example below plots three species by year and site.  However, 
  I would like the points to occur in groups horizontally, rather than 
on top of each other.

I thought jitter might work, but haven't been successful in getting it 
to do what I want.

Any ideas?  Thanks in advance.

John



wt=rnorm(27,5,0.6)
yr=rep(c(2000,2001,2002),each=3)
vill=c("Kabo","Pkl","Lnd")
spp=c("A","B","C")
df=data.frame(wt,yr,vill,spp)
err=wt*0.025

xYplot(Cbind(wt, wt-err, wt+err)~yr|factor(vill), groups=factor(spp), 
    	data=df,scales=list(alternating=1, y=list(relation="free"), 		 
x=list(at=c(2000,2001,2002))))

On Mon, 2008-08-18 at 19:25 -0400, John Poulsen wrote:
> Hello,
> 
> The simple example below plots three species by year and site.  However, 
>   I would like the points to occur in groups horizontally, rather than 
> on top of each other.
> 
> I thought jitter might work, but haven't been successful in getting it 
> to do what I want.
> 
Hi John,
I don't know whether this is what you want, but the cluster.overplot
function (plotrix) turns coincident points into groups of up to nine
points. You may be able to adapt the code for use in xYplot.

Jim