_______________________________________________________________________________________ substr is vectorised, so it should work fine without needing an explicit loop. -- Hong Ooi Senior Research Analyst, IAG Limited 388 George St, Sydney NSW 2000 +61 (2) 9292 1566 -----Original Message----- From: r-help-bounces at stat.math.ethz.ch [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Kimpel, Mark William Sent: Thursday, 18 January 2007 11:27 AM To: r-help at stat.math.ethz.ch Subject: [R] help with regexpr in gsub I have a very long vector of character strings of the format "GO:0008104.ISS" and need to strip off the dot and anything that follows it. There are always 10 characters before the dot. The actual characters and the number of them after the dot is variable. So, I would like to return in the format "GO:0008104" . I could do this with substr and loop over the entire vector, but I thought there might be a more elegant (and faster) way to do this. I have tried gsub using regular expressions without success. The code gsub(pattern= "\.*?" , replacement="", x=character.vector) correctly locates the positions in the vector that contain the dot, but replaces all of the strings with "". Obviously not what I want. Is there a regular expression for replacement that would accomplish what I want? Or, does R have a better way to do this? Thanks, Mark Mark W. Kimpel MD (317) 490-5129 Work, & Mobile (317) 663-0513 Home (no voice mail please) 1-(317)-536-2730 FAX ______________________________________________ R-help at stat.math.ethz.ch 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. _______________________________________________________________________________________ The information transmitted in this message and its attachme...{{dropped}}