Re: [Rd] gsub + backslashes

From: Gabor Grothendieck <ggrothendieck_at_gmail.com>
Date: Mon 24 Apr 2006 - 14:30:32 GMT

\ is a special character in regular expressions so you need to escape it as \\ but putting \\ between quotes give you only \ so you need \\\\ to get \\. Any of these would work:

gsub("\\\\", "x", "\\alpha")
gsub("[\\]", "x", "\\alpha")
sub(".", "x", "\\alpha") # assumes \ is first character gsub("\\", "x", "\\alpha", fixed = TRUE) chartr("\\", "x", "\\alpha")

On 4/24/06, Torsten Hothorn <Torsten.Hothorn@rzmail.uni-erlangen.de> wrote:
>
> Dear developeRs,
>
> I thought that backslashes can be escaped in the usual way (and I think I
> did this before) but I can't see why
>
> R> gsub("\\", "x", "\alpha")
> Error in gsub(pattern, replacement, x, ignore.case, extended, fixed,
> useBytes) :
> invalid regular expression '\'
>
> gives an error. Or am I just blind?
>
> Best,
>
> Torsten
>
> R> version
> _
> platform i686-pc-linux-gnu
> arch i686
> os linux-gnu
> system i686, linux-gnu
> status Under development (unstable)
> major 2
> minor 4.0
> year 2006
> month 04
> day 18
> svn rev 37840
> language R
> version.string R version 2.4.0 Under development (unstable) (2006-04-18
> r37840)
>
> ______________________________________________
> R-devel@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>



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https://stat.ethz.ch/mailman/listinfo/r-devel Received on Tue Apr 25 01:55:49 2006

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