R help - Oct 2012 - xyplot(): How to Apply Conditional?

The xyplot help page covers several lattice plots and states that with the
exception of xyplot the formula can have the form x ~ y | c. I need to
generate x-y plots for only one of two levels of a conditioning factor. What
is the recommended way to do this?

Rich

On Oct 17, 2012, at 10:44 AM, Rich Shepard wrote:
>  The xyplot help page covers several lattice plots and states that  
> with the
> exception of xyplot the formula can have the form x ~ y | c. I need to
> generate x-y plots for only one of two levels of a conditioning  
> factor. What
> is the recommended way to do this?
What exactly is being requested? Do you just need to learn how to use  
the subset parameter? I would not think that the conditioning syntax  
would be used when there were only one level desired.

-- 
David Winsemius, MD
Alameda, CA, USA