[R] Selecting columns whose names contain "mutated" except when they also contain "non" or "un"

[peter dalgaard]

On Apr 24, 2012, at 19:15 , Rui Barradas wrote:
> 
> Has anyone realized that both 'non' and 'un' end with the same letter? The
> only one we really need to check?
> 
> (tmp <- c('mutation','nonmutated','unmutated','verymutated','other')) 
> 
> i1 <- grepl("muta", tmp)
> i2 <- grepl("nmuta", tmp)
> 
> tmp[i1 & !i2]
> 


Yes, I was wondering why people were avoiding the obvious use of grepl(). I'm not too happy about the "nmuta" technique though: What about "deletionmutation" and such? Might as well do the safe(r) thing:

i2 <- grepl("unmuta", tmp) | grepl("nonmuta", tmp) 

-- 
Peter Dalgaard, Professor,
Center for Statistics, Copenhagen Business School
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Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com