Try this also: > grep("arg", "arg.symptom", value = TRUE, invert = TRUE) character(0) > grep("arg", "liver.symptom", value = TRUE, invert = TRUE) [1] "liver.symptom" >
On Fri, Apr 1, 2011 at 1:33 PM, array chip <arrayprof...@yahoo.com> wrote: > Great. thank you Bernd! Learned a new thing here. > > John > > > > > ________________________________ > From: Bernd Weiss <bernd.we...@uni-koeln.de> > > Cc: r-help@r-project.org > Sent: Thu, March 31, 2011 6:19:25 PM > Subject: Re: [R] regular expression > > Am 31.03.2011 21:06, schrieb array chip: >> Ok then this code didn't do what I wanted. I want "not including >> 'arg' before '.symptom'", not individual letters of "arg", but rather >> as a word. >> >> Bill Dunlap suggested using invert=T, it works for single 1 >> condition, but not for 2 conditions here: not including "arg" before >> ".", but at the same time, does include ".symptom". >> >> Any other suggestions would be appreciated > > This does work (but I am by no means an expert in regex...). I am using > 'negative lookbehind'[1] to define an expression like 'arg'. > >> grep('(?<!(arg))\\.symptom',"arg.symptom",value=T, perl = T) > character(0) > >> grep('(?<!(arg))\\.symptom',"liver.symptom",value=T, perl = T) > [1] "liver.symptom" > > Bernd > > [1] http://www.regular-expressions.info/lookaround.html > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O ______________________________________________ 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.