[R] gsub issue in R 2.11.1, but not present in 2.9.2

[Bert Gunter]

Uwe:

Did you forget to add the "fixed = TRUE" parameter to your gsub call in your
reply? 

> gsub("N\\A", "NA", "N\\A")
[1] "N\\A"

> gsub("N\\A","NA","N\\A",fixed=TRUE)
[1] "NA"

I only mention it because there is already sufficient confusion that the
typo may totally bewilder people.

-- Bert

Bert Gunter
Genentech Nonclinical Statistics

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
> On Behalf Of Uwe Ligges
> Sent: Tuesday, June 29, 2010 4:11 AM
> To: Jason Rupert
> Cc: r-help at r-project.org
> Subject: Re: [R] gsub issue in R 2.11.1, but not present in 2.9.2
> 
> 
> 
> On 29.06.2010 12:47, Jason Rupert wrote:
> > Previously in R 2.9.2 I used the following to convert from an improperly
> formatted NA string into one that is a bit more consistent.
> >
> >
> > gsub("N\A", "NA", "N\A", fixed=TRUE)
> >
> > This worked in R 2.9.2, but now in R 2.11.1 it doesn't seem to work an
> throws the following error.
> > Error: '\A' is an unrecognized escape in character string starting "N\A"
> >
> > I guess my questions are the following:
> > (1) Is this expected behavior?
> > (2) If it is expected behavior, what is the proper way to replace "N\A"
> with "NA" and "N\\A" with "NA"?
> 
> 
> If your original text "thestring" contains "N\A", then the R
> representation is "N\\A", and hence
> 
> gsub("N\\A", "NA", thestring)
> 
> If you want to try explicitly, you need to write
> 
> gsub("N\\A", "NA", "N\\A")
> 
> If you original text contains two backslashes, both have to be escaped as
> in
> 
> gsub("N\\\\A", "NA", thestring)
> 
> Uwe Ligges
> 
> 
> > Thank you again for all the help and insight.
> >
> > ______________________________________________
> > R-help at 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.
> 
> ______________________________________________
> R-help at r-project.org mailing list
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> PLEASE do read the posting guide http://www.R-project.org/posting-
> guide.html
> and provide commented, minimal, self-contained, reproducible code.