[R] Singling out observations

Kurt_Helf at nps.gov Kurt_Helf at nps.gov
Mon Feb 13 21:30:24 CET 2012

     I am attempting to plot observations of a cave aquatic invertebrate
dating from 1901-2004.  I can come up with a nice lattice plot of the eight
sites from which I have data easily enough.  However, I'd like to be able
to highlight the 0 observations on the plots, i.e., attempts to find it at
the site were unsuccessful.  I'd like to be able to highlight these
observations with either a symbol or a color.  Here's a sample of the data
 (Embedded image moved to file: pic17437.jpg)

Here's my code for the plot:
xyplot(No.Invert~Year|Reach, data=Invert.Coll.1901.2004,
       ylab="No. Invert 'collected'",

Kurt Lewis Helf, Ph.D.
EEO Counselor
National Park Service
Cumberland Piedmont Network
P.O. Box 8
NPS Warehouse
61 Maintenance Rd.
Mammoth Cave, KY 42259
Ph: 270-758-2163
Lab: 270-758-2151
Fax: 270-758-2609
Cumberland Piedmont Network (CUPN) Homepage:
Science, in constantly seeking real explanations, reveals the true majesty
of our world in all its complexity.
-Richard Dawkins

[Scientific] theories are passed on not as dogmas but rather with the
challenge to discuss them and improve upon them.
-Karl Popper

...consider yourself a guest in the home of other creatures as significant
as yourself.
-Wayside at Wilderness Threshold in McKittrick Canyon, Guadalupe Mountains
National Park, TX

CUPN Forest Pest Monitoring Website:

CUPN Cave Cricket Monitoring Website:

CUPN Cave Aquatic Biota Monitoring Website:

More information about the R-help mailing list