R help - Nov 2006 - grep searching for sequence of 3 consecutive upper case letters

Hello,

I need to identify all elements which have a sequence of 3 consecutive upper
case letters, anywhere in the string.

I tested my grep expression on this site: http://regexlib.com/RETester.aspx

But when I try it in R, it does not filter anything.

str <-c("AGH", "this WOUld be good", "Not Good at
All")
str[grep('[A-Z]{3}',str)] #looking for a sequence of 3 consecutive upper
case letters

[1] "AGH"                "this WOUld be good" "Not Good
at All"

Any idea?

Pierre

**************************************************
AVIS DE NON-RESPONSABILITE: Ce document transmis par courrie...{{dropped}}

Try

str[grep('[[:upper:]]{3}',str)]


On 06/11/06, Lapointe, Pierre <Pierre.Lapointe at nbf.ca>
wrote:
> Hello,
>
> I need to identify all elements which have a sequence of 3 consecutive
upper
> case letters, anywhere in the string.
>
> I tested my grep expression on this site: http://regexlib.com/RETester.aspx
>
> But when I try it in R, it does not filter anything.
>
> str <-c("AGH", "this WOUld be good", "Not Good
at All")
> str[grep('[A-Z]{3}',str)] #looking for a sequence of 3 consecutive
upper
> case letters
>
> [1] "AGH"                "this WOUld be good" "Not
Good at All"
>
> Any idea?
>
> Pierre
>
> **************************************************
> AVIS DE NON-RESPONSABILITE: Ce document transmis par courrie...{{dropped}}
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
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http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

-- 
================================David Barron
Said Business School
University of Oxford
Park End Street
Oxford OX1 1HP

"Lapointe, Pierre" <Pierre.Lapointe at nbf.ca> writes:
> Hello,
> 
> I need to identify all elements which have a sequence of 3 consecutive
upper
> case letters, anywhere in the string.
> 
> I tested my grep expression on this site: http://regexlib.com/RETester.aspx
> 
> But when I try it in R, it does not filter anything.
> 
> str <-c("AGH", "this WOUld be good", "Not Good
at All")
> str[grep('[A-Z]{3}',str)] #looking for a sequence of 3 consecutive
upper
> case letters
> 
> [1] "AGH"                "this WOUld be good" "Not
Good at All"
> 
> Any idea?
There are multiple versions of RE's, and fine details resolve in
different ways. Don't expect the RETester to hold the Final Truth; it
seems to relate to a particular programming environment, which is not
R.  
> grep('[A-Z]{3}', str, perl=TRUE)
[1] 1 2

Not only that, but
> grep('[ABCDEFGHIJKLMNOPQRSTUVWXYZ]{3}', str)
[1] 1 2

Hint: What is your collating sequence?
> Sys.setlocale("LC_COLLATE", "C")
[1] "C"
> grep('[A-Z]{3}', str)
[1] 1 2


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