[R] numeric to factor via lookup table

[Jonathan Greenberg]

R-helpers:

Hopefully this is an easy one.  Given a lookup table:

mylevels <- data.frame(ID=1:10,code=letters[1:10])

And a set of values (note these do not completely cover the mylevels range):

values <- c(1,2,5,5,10)

How do I convert values to a factor object, using the mylevels to
define the correct levels (ID matches the values), and code is the
label?

--j

-- 
Jonathan A. Greenberg, PhD
Assistant Professor
Global Environmental Analysis and Remote Sensing (GEARS) Laboratory
Department of Geography and Geographic Information Science
University of Illinois at Urbana-Champaign
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