[R] strsplit and regex

Redding, Matthew Matthew.Redding at dpi.qld.gov.au
Thu Oct 16 00:13:18 CEST 2008

 Hi All, 

Just to make that question a bit harder - how 
do I apply that string extraction to vector of these time strings?


Matt Redding

>-----Original Message-----
>From: r-help-bounces at r-project.org 
>[mailto:r-help-bounces at r-project.org] On Behalf Of Redding, Matthew
>Sent: Thursday, 16 October 2008 7:54 AM
>To: r-help at r-project.org
>Subject: [R] strsplit and regex
>Hi All, 
>Is there a means to extract the "10" from "23:10:34" in one 
>pass using strsplit (or something else)?
>tst <- "23:10:34"
>For example my attempt
>[1] ""   ""   "34"
>Obviously it is matching the first two instances of [0-9]. 
>Note that there may be only one digit before the first ":".
>How do I anchor the match to the begginning or better still, 
>just extract the number I want in one pass?
>I can see that I can add "begin" to the beginning of the 
>string, and match that and do something similar at the end, 
>getting rid of empty strings etc - but I think it would take 
>about 3 passess  - and the files are large. And besides that 
>code would be unlovely.
>Kind regards,
>Matt Redding

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