[R] replace "%" with "\%"

[Michael Dewey]

At 15:46 15/05/2009, Liviu Andronic wrote:
>Dear all,
>I'm trying to gsub() "%" with "\%" with no obvious success.

Hello Liviu,
When I posted a similar question a few years ago one helpful response 
introduced me to nchar
 > nchar("%")
[1] 1
 > nchar("\%")
[1] 1
Warning messages:
1: '\%' is an unrecognized escape in a character string
2: unrecognized escape removed from "\%"
 > nchar("\\%")
[1] 2
 >

Of course other people have already solved your specific problem but 
nchar is a handy tool I find.

(And apologies to the person who helped me last time but I cannot 
find the post in the archive for some reason and so am reluctant to 
credit them in case I got it wrong)

> > temp1 <- c("mean", "sd",   "0%",   "25%",  "50%",  "75%",  "100%")
> > temp1
>[1] "mean" "sd"   "0%"   "25%"  "50%"  "75%"  "100%"
> > gsub("%", "\%", temp1, fixed=TRUE)
>[1] "mean" "sd"   "0%"   "25%"  "50%"  "75%"  "100%"
>Warning messages:
>1: '\%' is an unrecognized escape in a character string
>2: unrecognized escape removed from "\%"
>
>I am not quite sure on how to deal with this error message. I tried
>the following
> > gsub("%", "\\%", temp1, fixed=TRUE)
>[1] "mean"   "sd"     "0\\%"   "25\\%"  "50\\%"  "75\\%"  "100\\%"
>
>Could anyone suggest how to obtain output similar to:
>[1] "mean"   "sd"     "0\%"   "25\%"  "50\%"  "75\%"  "100\%"
>
>Thank you,
>Liviu
>
>
>
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Michael Dewey
http://www.aghmed.fsnet.co.uk