R help - Aug 2018 - searching for a specific row name in R

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]]

Hello Deepa,

sum(x[,2] == "A501")
or
which(x[,2] == "A501")
.
Best,
Albrecht


-- 
  Albrecht Kauffmann
  alkauffm at 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 at 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.

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 at r-project.org on behalf of alkauffm at fastmail.fm>
wrote:

    Hello Deepa,
    
    sum(x[,2] == "A501")
    or
    which(x[,2] == "A501")
    .
    Best,
    Albrecht
    
    
    -- 
      Albrecht Kauffmann
      alkauffm at 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 at 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 at 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.