gsub('.+; (.+);.+','\\1',x) or if you just want the value out:
gsub('.+; Surv\\(months\\): ([0-9]+);.+','\\1',x) You can also look at strsplit: > strsplit(x,';') [[1]] [1] "99-625: Cell type: S" " Surv(months): 21" " STATUS(0=alive, 1=dead): 1" > lapply(strsplit(x,';'),'[',2) [[1]] [1] " Surv(months): 21" But i would follow David's second suggestion and just read them in with sep=';' instead. Justin On Wed, Feb 29, 2012 at 11:24 AM, Fred G <bayespoker...@gmail.com> wrote: > Computer Friends, > > with the following example lines: > > [107] "98-610: Cell type: S; Surv(months): 6; STATUS(0=alive, 1=dead): 1" > > [108] "99-625: Cell type: S; Surv(months): 21; STATUS(0=alive, 1=dead): 1" > > i want to be able to isolate the number of months of survival for each row. > > is there a regular expression that can find the first instance of a ";", > delete everything in front of it-- and find the second instance of an ";" > and delete everything behind it? in python there is a function line.find(), > would be grateful to hear the R equiv; or, any other better alternatives to > get the number of months of survival stored as a variable. > > Much Thank You! > > [[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. > [[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.