[R] Quick GREP challenge

[David Winsemius]

On Aug 26, 2010, at 8:15 AM, Gabor Grothendieck wrote:

> On Thu, Aug 26, 2010 at 6:16 AM, Dimitri Shvorob
> <dimitri.shvorob at gmail.com> wrote:
>>
>>> grep("f[0-9]+=", "f1=5,f22=3,", value = T)
>> [1] "f1=5,f22=3,"
>>
>> How do I make the line output c("f1", "f22") instead? (Actually,  
>> c(1,22)
>> would be even better).
>>
>
> strapply in gsubfn extracts matches based on content rather than
> delimiters.  See home page for more info http://gsubfn.googlecode.com
>
>> library(gsubfn)
>> x <- "f1=5,f22=3,"
>> strapply(x, "f\\d+")[[1]]
> [1] "f1"  "f22"

I read the request as for c(1,22) offered without quotes so t emeaning  
was obscure but perhaps this is what OP wanted:

as.numeric( strapply(x, "f(\\d+)=")[[1]] )
[1]  1 22
# or
 > as.numeric(unlist(strapply(x, "f(\\d+)=")))
[1]  1 22



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David Winsemius, MD
West Hartford, CT