It's no harder: use sub() which is vectorized. You've not actually
defined the pattern, but here is my guess at your intentions:
x <- c("23:10:34", "23:20:30")
sub("([0-9][0-9]:)([0-9][0-9])(:[0-9][0-9])", "\\2", x)
Another interpetation would be
sub("([^:]*:)([^:]*)(:[^:]*)", "\\2", x)
for <something>:<desired>:<something else>
E.g. is 9:13:3 valid or not?
On Thu, 16 Oct 2008, Redding, Matthew wrote:
Hi All,
Just to make that question a bit harder - how
do I apply that string extraction to vector of these time strings?
Thanks,
Matt Redding
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Redding, Matthew
Sent: Thursday, 16 October 2008 7:54 AM
To: r-help@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
strsplit(as.character(tst),"^[0-9]*:")
gives
[[1]]
[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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