Hi, You may try: test[!grepl("(?<=AARSD1)[-\\d]", test, perl=T)]
A.K. On Friday, June 27, 2014 6:43 AM, C Lin <bac...@hotmail.com> wrote: Hi Duncan, Thanks for trying to help. Sorry for not being clear. The string I'd like to get is 'AARSD1' It can be followed or preceded by white space or // or nothing so, from test <- c('AARSD11','AARSD1-','AARSD1//','AARSD1 //','//AARSD1','AARSD1'); I want to match only 'AARSD1//','AARSD1 //','//AARSD1','AARSD1' Thanks, Lin ---------------------------------------- > From: dulca...@bigpond.com > To: bac...@hotmail.com; r-help@r-project.org > Subject: RE: [R] regular expression help > Date: Fri, 27 Jun 2014 10:59:29 +1000 > > Hi > > You only have a vector of length 5 and I am not quite sure of the string you > are testing > so try this > > grep('[/]*\\<AARSD1\\>[/]*',test) > > Duncan > > Duncan Mackay > Department of Agronomy and Soil Science > University of New England > Armidale NSW 2351 > Email: home: mac...@northnet.com.au > > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf Of C Lin > Sent: Friday, 27 June 2014 10:05 > To: r-help@r-project.org > Subject: [R] regular expression help > > Dear R users, > > I need to match a string. It can be followed or preceded by whitespace or // > or nothing. > How do I code it in R? > > For example: > test <- c('AARSD11','AARSD1-','AARSD1//','AARSD1 //','//AARSD1'); > grep('AARSD1(\\s*//*)',test); > > should return 3,4,5 and 6. > > Thanks in advance for your help. > > Lin > ______________________________________________ > R-help@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. > ______________________________________________ R-help@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. ______________________________________________ R-help@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.