[R] specify xlim for each panel

[Aimin Yan]

I draw dotplot using the following code:

sd.dotplot<-dotplot(data.47.nmr$om_sd ~ as.factor(data.47.nmr$position) 
|as.factor(data.47.nmr$pr), data = data.47.nmr,layout=c(1,1),
xlab="Position", xlim=range(data.47.nmr$position),ylab="Sd", main="Changes 
of omega angle in different positions",
scales = list(x = list(rot = 45)))

However I get same xlim for each panel,
Actually xlim is different for each panel, it is based on data.47.nmr$position.

How can I modify this code so I can deal with the different xlim for each panel

thanks,

Aimin