[R] searching for a specific row name in R

Deepa deep@m@hm@||@c @end|ng |rom gm@||@com
Tue Aug 14 06:16:15 CEST 2018


I have a hundred identifier names that I want to check from the second
column of a matrix with 6000 entries in the column.
Instead of using  R > c("d", "v", "4", "s") %in% letters , is there an
alternative?

I have the hundred identifier names that are of my interest stored in an
array.




On Tue, Aug 14, 2018 at 9:16 AM, Boris Steipe <boris.steipe using utoronto.ca>
wrote:

> Use the %in% operator:
>
> help('%in%')
>
> e.g.
>
> R > c("d", "v", "4", "s") %in% letters
> [1]  TRUE  TRUE FALSE  TRUE
>
>
> B.
>
>
> > On 2018-08-13, at 23:36, Deepa <deepamahm.iisc using gmail.com> wrote:
> >
> > Hi Don,
> >
> > When there is a list of identifier names that I want to check, the only
> way
> > is to loop over each entry stored in the list of identifier names or is
> > there is there any other shortcut?
> >
> > Many thanks for the response?
> >
> > On Mon, Aug 13, 2018 at 8:18 PM, MacQueen, Don <macqueen1 using llnl.gov>
> wrote:
> >
> >> Or to return a logical value, i.e., TRUE if the column contains the
> value,
> >> FALSE if it does not:
> >>
> >>  any( x[,2] == 'A501' )
> >>
> >> -Don
> >> --
> >> Don MacQueen
> >> Lawrence Livermore National Laboratory
> >> 7000 East Ave., L-627
> >> Livermore, CA 94550
> >> 925-423-1062
> >> Lab cell 925-724-7509
> >>
> >>
> >>
> >> On 8/13/18, 12:09 AM, "R-help on behalf of Albrecht Kauffmann" <
> >> r-help-bounces using r-project.org on behalf of alkauffm using fastmail.fm> wrote:
> >>
> >>    Hello Deepa,
> >>
> >>    sum(x[,2] == "A501")
> >>    or
> >>    which(x[,2] == "A501")
> >>    .
> >>    Best,
> >>    Albrecht
> >>
> >>
> >>    --
> >>      Albrecht Kauffmann
> >>      alkauffm using fastmail.fm
> >>
> >>    Am Mo, 13. Aug 2018, um 07:10, schrieb Deepa Maheshvare:
> >>> Hello Everyone,
> >>>
> >>> I have a 1000 x 20 matrix. The second column of the matrix has the
> >> names
> >>> of identifiers. How do I check when a certain identifier is present
> >> in
> >>> the set of 1000 identifier names present in the second column. For
> >>> instance, let the names of identifiers be A1,A2,...A1000. I want to
> >>> check whether A501 is present .How can this be checked?
> >>>
> >>> Any help will be highly appreciated.
> >>>
> >>>
> >>>  [[alternative HTML version deleted]]
> >>>
> >>> ______________________________________________
> >>> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >>> 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 using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >>    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.
> >>
> >>
> >>
> >
> >       [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> > 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.
>
>

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