mget empty strings

nm <- c("x", "", "y")
x <- 10; y <- 20
myObj <- structure(vector(mode="list", length=length(nm)), names=nm)
goodNames <- nm[nchar(nm) > 0]
myObj[goodNames] <- mget(goodNames, .GlobalEnv)
myObj

From: Georg Otto

Dear R community,

I am a beginner to R and have a question concerning mget, 
about I could 
not find anything in the various documentation.

I have a column in a dataframe x for which I want to get values in y:

mget(x[,1], env=y, ifnotfound=NA)

I receive an error mesage:

Error in mget(x[, 1], env = y, ifnotfound = NA) :
         attempt to use zero-length variable name

this is probably due to the fact that some of the values in x[,1] are 
empty ("")

I would like to get a "NA" for these values, and the found value for 
those where mget finds one. Could anyone tell me how this is done 
efficiently?

Thanks a lot in advance!

Georg


P.S. I am in digest mode, cc'ing the answer directly to me 
would be nice


-- 
Georg Wilhelm Otto
Max-Planck-Institute for Developmental Biology
Spemannstrasse 35/III
D-72076 Tuebingen Germany
phone: +49-7071-601 401
http://www.eb.tuebingen.mpg.de