thanks stephan. i'd been trying to make gsub work, but couldnt make it replace the whole expression. so i'd resorted to trying to loop with grep - but with two problems. firstly, i cant seem to make the loop 'remember' the substitutions it makes (see below). secondly, it feels like this is a really inefficient way of doing something quite simple anyhow.
colours <- as.character(paste(letters,colours(),"stuff",LETTERS)) target <- c("red","blue","green","gray") new.colour <-colours for (i in length(target)) { x <- target[i] new.colour[grep((x),new.colour)] <- x return(new.colour) } On Sat, Mar 28, 2009 at 9:45 AM, Stephan Kolassa <stephan.kola...@gmx.de>wrote: > Hi Simeon, > > ?gsub > > HTH, > Stephan > > simeon duckworth schrieb: > >> I am trying to simplify a text variable by matching and replacing it with >> a >> string in another vector >> >> so for example in >> colours <- paste(letters,colours(),"stuff",LETTERS) >> >> find and replace with ("red","blue","green","gray","yellow","other") - >> irrespective of case >> >> its a large dataset, so i'd like to be able to do this as efficiently as >> possible. >> >> thanks for any help >> >> [[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.