[R] why does regexpr not work with '.'

From: Jonathan Williams <jonathan.williams_at_dpag.ox.ac.uk>
Date: Tue, 15 Apr 2008 11:27:14 +0100


Dear R Helpers,

I am running R 2.6.2 on a Windows XP machine.

I am trying to use regexpr to locate full stops in strings, but, without success.

Here an example:-

f="a,b.c_at_d:" #define an arbitrary test string regexpr(',',f) #find the occurrences of ',' in f - should be one at location 2

               # and this is what regexpr finds
#[1] 2
#attr(,"match.length")
#[1] 1

regexpr('@',f) #find occurrences of '@' in f - should be one at location 6

               # and this is what regexpr finds
#[1] 6
#attr(,"match.length")
#[1] 1

regexpr('.',f) #find the occurrences '.' in f - should be one at location 4

                   # but regexpr gives 1 at location 1
#[1] 1
#attr(,"match.length")
#[1] 1

Sorry if I am missing something obvious. I'd be very grateful if someone would
please show me how to use regexpr to locate '.' in my string!

Thanks,

Jonathan Williams



R-help_at_r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Received on Tue 15 Apr 2008 - 10:31:02 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Tue 15 Apr 2008 - 11:30:28 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.

list of date sections of archive