[R] list substring

[Wacek Kusnierczyk]

calpeda wrote:
> hi
> I ve a list of item x = ( "xxxxx1"
>                                "xxxxx2"
>                                "yyyyx3")
>
> I need to extract a new vector y  = ( "xxxx",
>                                                    "xxxx",
>                                                    "yyyy"
> )
> I mean, for each item I need to extract the first 4 digit
> How is that possible?
>   

    sub('^(\\d{4}).*', '\\1', x, perl=TRUE)

vQ