[R] gsub warning message

[Uwe Ligges]

Talbot Katz wrote:
> Hi.
> 
> I am using R 2.5.1 on a Windows XP machine.  Here is an example of a piece 
> of code I was running in older versions of R on the same machine.  I am 
> looking for underscores and replacing them with periods.  This result is 
> from R 2.4.1:
> 
>> gsub ( "\\_+","\.","AAA_I")
> [1] "AAA.I"
> 
> Here is what I get in R 2.5.1:
> 
>> gsub ( "\\_+","\.","AAA_I")
> [1] "AAA.I"
> Warning messages:
> 1: '\.' is an unrecognized escape in a character string
> 2: unrecognized escape removed from "\."
> 
> I still get the same result, which is what I want, but now I get a warning 
> message.  Am I actually doing something wrong that the previous versions of 
> R didn't warn me about?  Or is this warning message unwarranted?  Is there a 
> fully approved method for getting the same functionality?  Thanks!

Yes, correct usage is either
   gsub ( "\\_+", ".", "AAA_I")
or
   gsub ( "\\_+", "\\.", "AAA_I")

Uwe Ligges



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