Many thanks to you and all others for solutions together with regular
expressions insights.
Petr
"Chuck Taylor" <ctay...@tibco.com> napsal dne 29.07.2009 19:45:10:
> Petr,
>
> Here is a different approach. It, in effect, works from the end of the
> string backwards, rather than from the beginning of the string forwards.
>
> substring(x, regexpr("[0-9]+$", x))
>
> The regular expression "[0-9]+$" finds a string of 1 or more ("+")
> digits ("[0-9]") followed by the end of the line ("$"). The regexpr()
> function returns the position in the string x where that regular
> expression begins. Feed that to substring() and you get the desired
> result. Both substring() and regexpr() work on vectors of strings.
>
> Best regards,
> Chuck Taylor
> TIBCO Spotfire Seattle
>
>
> -----Original Message-----
> From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org]
> On Behalf Of Petr PIKAL
> Sent: Wednesday, July 29, 2009 6:10 AM
> To: r-h...@stat.math.ethz.ch
> Subject: [R] regexpr virtue
>
> Hi all
>
> I have got something like that (actually those are column names)
>
> [51] "X19.2.300b...80" "X19.2.400v...80" "X19.2.400b...80"
> "X19.2.300v...90" "X19.2.300b...90"
> [56] "X19.2.400v...90" "X19.2..400b..90" "X19.2.300v...100"
> "X19.2.300b...100" "X19.2.400v...100"
>
> in character vector. I would like to get last n figures from this
> character vector but my regexpr unerstanding is inferior and I did not
> succeed.
> Please, is there anybody who can extract those n digits from end of each
>
> character string? If there were only 2 digits I could use substr but
> there
> can be one, two or three digits.
>
> ...
>
> Best regards
> Petr
______________________________________________
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.
