[R] Inserting Missing Data

Kurt_Helf at nps.gov Kurt_Helf at nps.gov
Wed Nov 10 22:38:03 CET 2010

     I'm attempting to insert missing data on the smallest size class of
cave cricket instars into a data frame. The data involve censusing
photoplots (plots) of roosting cave crickets in which we discern in four
instars or size classes.  I need to insert data on size class one into a
data frame that already has data on size classes two through four.  The
data can be merged by their cave name, year, month, region (near or far
from cave entrance), plot #, and Individual (IndID).  For example:
(Embedded image moved to file: pic14606.jpg)

As one example, I have data for size class (SC) one I can insert after
IndID #4 in the data above.  However, when I attempt to merge these two
data frames using the following commands:
I get the following message:
"WARNING: Warning in `[<-.factor`(`*tmp*`, ri, value = c(1L, 1L, 1L, 1L,
1L, 1L, 1L,  :
  invalid factor level, NAs generated"

Can anyone tell me what this means and how I might fix it?

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

The scientific tradition is distinguished from the pre-scientific tradition
in having two layers.  Like the latter it passes on its theories but it
also passes on a critical attitude towards them.  The 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

Cumberland Piedmont Network (CUPN) Homepage:

CUPN Forest Pest Monitoring Website:

CUPN Cave Cricket Monitoring Website:

CUPN Cave Aquatic Biota Monitoring Website:

More information about the R-help mailing list