Re: [R] Problem with the grep function

From: <Jan_Svatos_at_eurotel.cz>
Date: Thu 08 Jul 2004 - 17:47:19 EST


Hi Julie,

match is not exactly what you need, as it works with regular expressions and takes anything what includes a letter "b". For your case, there is perfectly suitable

which(nom=="b")

nom <- c("a","b","ab", "b")
which(nom=="b")
[1] 2 4

Jan

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



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https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Thu Jul 08 18:05:38 2004

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