[R] searching for a specific row name in R

[Boris Steipe]

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.