[R] ploting 2 variables in a lattice xyplot

[Douglas Bates]

Ernesto Jardim <ernesto at ipimar.pt> writes:

> Hi,
> 
> I want to plot 2 variables (confidence intervals) in a single xyplot. I
> have a dataframe with variables Yup, Ylo, X and Z and I want to have a
> xyplot with both variables ploted. I'm trying with 
> 
> xyplot(Yup~X|Z, panel=function(x){...})
> 
> but this way I'm not able to pass variable Ylo into the function...
> 
> How can I do this ?

According to the "formula" description on the manual page for xyplot
you can use

xyplot(Ylo+Yup~X|Z, allow.multiple=TRUE)

Did you try that?