Thanks Bernd! I tried your approach with my real example, sometimes it worked, sometimes it didn't. For example
grep('[^(arg)]\\.symptom',"stomach.symptom",value=T) [1] "stomach.symptom" grep('[^(arg)]\\.symptom',"liver.symptom",value=T) character(0) I think both examples should return the text, but the 2nd example didn't. What was wrong here? Thanks John ________________________________ From: Bernd Weiss <bernd.we...@uni-koeln.de> Sent: Thu, March 31, 2011 5:32:25 PM Subject: Re: [R] regular expression Am 31.03.2011 19:31, schrieb array chip: > Hi, I am stuck on this: how to specify a match pattern that means not > to include "abc"? > > I tried: > > grep("^(abc)", "hello", value=T) should return "hello". > grep("[^(abc)]", "hello", value=T) [1] "hello" HTH, Bernd [[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.