[R] Problem with the grep function

Wolski wolski at molgen.mpg.de
Thu Jul 8 09:49:00 CEST 2004


Or you must mark the word beginning with ^ and the end $ if you like to use grep.

grep("^b$",nom)


Sincerely
Eryk


*********** REPLY SEPARATOR  ***********

On 7/8/2004 at 9:20 AM aubert at inapg.fr wrote:

>>>Let me present to you my problem :
>>>
>>>I have a character vector x and I would like to  obtain the indices of
>>>the 
>>>elements of
>>>this vector that yielded exactly a match.
>>>
>>>For example,  x=nom, pattern="b", I would to obtain 2 because "b" is on
>>>the 
>>>second position.
>>>
>>>First program :
>>>nom <- c("a","b","ab")
>>>grep("b",nom)
>>>2 3
>>>
>>>Then I try the option extended =FALSE (instead of TRUE by default) and I 
>>>obtain '2 3' a second time.
>>>
>>>Please can you help me : How can I obtain only 2 in using the grep
>>>function 
>>>(without using the match function).
>>>
>>>Thanks you
>>>
>>>Julie AUBERT
>>>
>>>______________________________________________
>>>R-help at stat.math.ethz.ch mailing list
>>>https://www.stat.math.ethz.ch/mailman/listinfo/r-help
>>>PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html



Dipl. bio-chem. Eryk Witold Wolski    @    MPI-Moleculare Genetic   
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