[R] impose points on lattice plot

[Luis Ridao Cruz]

R-help,

I'm using the lattice package to plot 2 variables (vekt ~ aldur)
conditioned to a third (kyn * 2 categories).

I use the following:

xyplot(vekt ~ aldur|kyn, , data = sexSu)


I want to superimpose the average(vekt) by 'aldur' 
conditioned to kyn by using something like:

xyplot(vekt~aldur|kyn, subset = aldur <= 12
, data = sexSu, panel = function(x, y)
       {
       panel.xyplot(x, y)
       panel.points(x,mean(y),col=2,cex=2 )
       }) 


but th output is just a horozontal line ( the average of 'vekt')
in both panels I guess)

How can be done?


Thanks in advance


> version
               _                           
platform       i386-pc-mingw32             
arch           i386                        
os             mingw32                     
system         i386, mingw32               
status                                     
major          2                           
minor          4.1                         
year           2006                        
month          12                          
day            18                          
svn rev        40228                       
language       R                           
version.string R version 2.4.1 (2006-12-18)
>