On Apr 23, 2012, at 12:10 PM, Paul Miller wrote:
Hello All,
Started out awhile ago trying to select columns in a dataframe whose
names contain some variation of the word "mutant" using code like:
names(KRASyn)[grep("muta", names(KRASyn))]
The idea then would be to add together the various columns using
code like:
KRASyn$Mutant_comb <- rowSums(KRASyn[grep("muta", names(KRASyn))])
What I discovered though, is that this selects columns like
"nonmutated" and "unmutated" as well as columns like "mutated",
"mutation", and "mutational".
So I'd like to know how to select columns that have some variation
of the word "mutant" without the "non" or the "un". I've been
looking around for an example of how to do that but haven't found
anything yet.
Can anyone show me how to select the columns I need?
If you want only columns whose names _begin_ with "muta" then add the
"^" character at the beginning of your pattern:
names(KRASyn)[grep("^muta", names(KRASyn))]
(This should be explained on the ?regex page.)
--
David Winsemius, MD
West Hartford, CT
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
