[R-sig-eco] Help plotting time series from multiple years?

[Raphael Mazor]

I would like to make a lattice plot of a variable by date from multiple 
years, where each panel is a different station, and each year is 
represented by a different line color. My data look something like this:

Station    Date    Score
Site1    5/19/2009    552
Site1    6/23/2009    578
Site1    8/5/2009    604
Site1    9/15/2009    618
Site1    4/13/2010    610
Site1    5/11/2010    618
Site1    6/15/2010    118
Site1    7/20/2010    592
Site1    9/1/2010    590
Site2    5/18/2009    628
Site2    6/22/2009    590
Site2    8/4/2009    628
Site2    9/16/2009    610
Site2    10/20/2009    618
Site2    4/15/2010    200
Site2    5/11/2010    118
Site2    6/15/2010    217
Site2    7/20/2010    479
Site2    9/1/2010    353

I feel like this should be simple enough to do with Lattice using 
xyplot, but I'm not having much luck. Any suggestions?

Thanks!

-- 
Raphael D. Mazor
Freshwater Biologist
Southern California Coastal Water Research Project
3535 Harbor Blv Suite 110
Costa Mesa, CA 92626

Tel. (714) 755-3235
Fax. (714) 755-3299