So, a way could be:

gsub("(.*)_(.*)_(.*)_.*", "\\3",  "abcd_efgh_XXXXX_12ab3_dfsfd")

On Thu, Feb 10, 2011 at 3:47 PM, Soumendra <soumendra@gmail.com> wrote:

> Hi Henrique,
>
> I believe your solution is wrong as it is fitted to find 12ab3,
> whereas Yan seems to be asking for the characters after the second
> underscore and before the third underscore.
>
> For example, gsub(".*_.*_(.*)_.*", "\\1",
> "abcd_efgh_XXXXX_12ab3_dfsfd") would still yield 12ab3 even though, as
> I understand it, it should have output XXXXX.
>
> I think a straightforward solution would do the job:
>
> strsplit("abcd_efgh_12ab3_dfsfd", "_")[[1]][3]
>
> strsplit("abcd_efgh_XXXXX_12ab3_dfsfd", "_")[[1]][3] has the output
> XXXXX, for example.
>
> Of course, I would be wrong if Yan specifically wanted to find the
> string 12ab3. But in that case, he would have been asking for matching
> (and locating) that substring instead of extracting it.
>
> Regards,
>
> Soumendra
>
>
> --
> Soumendra Prasad Dhanee
> Quantitative Analyst, Neural Technologies and Software Pvt. Ltd.
>
> soumendra@neuraltechsoft.com, soumendra@maths.org.in, soumendra@gmail.com
> +91-7498076111, +91-8100428686
>
> --
> "When you understand why you dismiss all the other possible gods, you
> will understand why I dismiss yours." - Stephen Roberts
>
>
>
> On 10 February 2011 11:52, Henrique Dallazuanna <wwwhsd@gmail.com> wrote:
> > Try this:
> >
> > gsub(".*_.*_(.*)_.*", "\\1", "abcd_efgh_12ab3_dfsfd")
> >
> > On Thu, Feb 10, 2011 at 9:42 AM, Yan Jiao <y.jiao@ucl.ac.uk> wrote:
> >
> >> Dear R gurus,
> >>
> >>
> >>
> >> If I got a vector with string characters like "abcd_efgh_12ab3_dfsfd",
> >> how could I extract "12ab3", which is the characters after second
> >> underscore and before the third underscore?
> >>
> >>
> >>
> >> Tons of thanks
> >>
> >>
> >>
> >> yan
> >>
> >>
> >>
> >>
> >>
> >>
> >> **********************************************************************
> >> This email and any files transmitted with it are
> confide...{{dropped:10}}
> >>
> >> ______________________________________________
> >> R-help@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.
> >>
> >
> >
> >
> > --
> > Henrique Dallazuanna
> > Curitiba-Paraná-Brasil
> > 25° 25' 40" S 49° 16' 22" O
> >
> >        [[alternative HTML version deleted]]
> >
> >
> > ______________________________________________
> > R-help@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.
> >
> >
>



-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O

	[[alternative HTML version deleted]]

