[R] regex sub with specified number of characters

[Ivan Calandra]

Hi Johannes,

Not sure if this can be done with sub() only, but combining it with 
ifelse() apparently does what you want:
ifelse(nchar(a)==7, sub("^3","",a), a)

HTH,
Ivan

--
Ivan Calandra, PhD
University of Reims Champagne-Ardenne
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Le 06/10/15 16:38, Johannes Radinger a écrit :
> Hi
>
> I'd like to remove a leading "3" if my number is 7 digits long, if it is
> only 6 I don't want to anything.
> I think this should be possible with a 1-liner using sub() but I am not
> sure how to define the number of characters following the leading one.
>
> For example my vector:
>
> a <- c(3593857,384723,4395843,3398374)
>
> with sub("^3","",a) I also remove the leading from the second element which
> is only 6 digits long. So how to restrict that using sub? The final result
> should be
>
> a <- c(593857,384723,4395843,398374)
>
> Any suggestions?
>
> Best regards,
> Johannes
>
> 	[[alternative HTML version deleted]]
>
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