On Feb 5, 2013, at 9:49 AM, Seth Dickey wrote:
> I thought that I can use metacharacters such as \w to match word characters
> with one backslash. But for some reason, I need to include two backslashes.
>
>> grepl(pattern='\w', x="what")
> Error: '\w' is an unrecognized escape in character string starting "\w"
>
>> grepl(pattern='\\w', x="what")
> [1] TRUE
>
> I can't find the reason for this on the help pages. Does anyone know why?
The help page for ?regex says near the top ...
"Any metacharacter with special meaning may be quoted by preceding it with a
backslash. The metacharacters in EREs are . \ | ( ) [ { ^ $ * + ?, but note
that whether these have a special meaning depends on the context."
>
> Thanks!
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> [email protected] 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.
David Winsemius
Alameda, CA, USA
______________________________________________
[email protected] 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.
