[R] Help with regular expressions.

Bert Gunter bgunter@4567 @end|ng |rom gm@||@com
Tue Feb 9 03:49:46 CET 2021

> gsub("(.*\\.[^.]*)\\.(.*)","\\1-\\2", "aa.bcv.cdg")
[1] "aa.bcv-cdg"


Bert Gunter

"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )

On Mon, Feb 8, 2021 at 6:29 PM Rolf Turner <r.turner using auckland.ac.nz> wrote:

> I want to deal with strings of the form "a.b.c" and to change (using
> sub() or whatever is appropriate) the second "." to a "-", i.e. to
> change "a.b.c" to "a.b-c".  I want to leave the first "." as-is.
> I guess I could do a gsub(), changing all "."s to "-"s, and then do
> a sub() changing the first "-" back to a ".".  But this seems very
> kludgy.  There must be a sexier way.  Mustn't there?  Is there regular
> expression syntax for picking out the second occurence of a particular
> string?
> cheers,
> Rolf Turner
> --
> Honorary Research Fellow
> Department of Statistics
> University of Auckland
> Phone: +64-9-373-7599 ext. 88276
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