On Fri, 13-Nov-2009 at 03:13PM +0000, Giulio Di Giovanni wrote:
|>
|>
|>
|> Dear all,
|>
|>
|>
|> I cannot figure out how to solve a small problem (well, not for me), surely
somebody can help me in few seconds.
|>
|>
|>
|> I have a series of strings in a vector X of the type "xxx", "yyy", "zzz",
"IgA", "IgG", "kkk", "IgM", "aaa".
|>
|> I want to substitute every ENTIRE string beginning with "Ig" with "0".
|>
|> So, I'd like to have "xxx", "yyy", "zzz", "0", "0", "kkk", "0", "aaa".
|>
|>
|>
|> I can easily identify these strings with grep("^Ig", X), but if I use this
criterion in the sub() function (sub("^Ig", "0", X) I obviously get "0A", "0G"
etc.
|>
|>
|>
|> I didn't expect to do it in this way and I tried with metacharacters and
regexps in order to grep and substitute the whole word (\b \>, $). I don't post
here my tryings, because they were obviously wrong.
|>
|> Please can you help me?
I think this is what you need:
> X <- c("xxx", "yyy", "zzz", "IgA", "IgG", "kkk", "IgM", "aaa")
> X[grep("^Ig", X)] <- "0"
> X
[1] "xxx" "yyy" "zzz" "0" "0" "kkk" "0" "aaa"
>
HTH
--
~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.
___ Patrick Connolly
{~._.~} Great minds discuss ideas
_( Y )_ Average minds discuss events
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~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.
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