[R] Help with grep (and similar functions)

[Gabor Grothendieck]

Try this:

library(gsubfn)
pat <- "([[:upper:]][[:lower:]]*) "
s <- "Aaaa 3 x 0 Bbbb"

strapply(s, pat, backref =-1)[[1]]

or (not quite as general but works in this case):

pat <- "([[:upper:]][[:lower:]]*) "
s <- "Aaaa 3 x 0 Bbbb"

s.idx <- gregexpr(pat, s)[[1]]
substring(s, s.idx, s.idx + attr(s.idx, "match.length") - 2)

On 3/28/07, Alberto Monteiro <albmont at centroin.com.br> wrote:
> This works:
>
> grep("([A-Za-z]*) ", "Aaaa 3 x 0 Bbbb") # 1
>
> This also works:
>
> grep("([A-Za-z]*) ", "Aaaa 3 x 0 Bbbb", value=T) # Aaaa 3 x 0 Bbbb
>
> However, I want a grep that returns the _matched_ pattern, which, in this
> case, would be Aaaa. How can I do it?
>
> Alberto Monteiro
>
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