the colsplit function in the reshape package does this really easily. --ista
> ---------- Forwarded message ---------- > From: "Dry, Jonathan R" <jonathan....@astrazeneca.com> > To: <r-help@R-project.org> > Date: Fri, 25 Sep 2009 15:01:46 +0100 > Subject: [R] Spliting columns, strings or reg exp returning substrings > Currently as the first column in a data frame I have string values in the > format xx_yy - I want to create a new column with just the substring xx (for > each row in turn). Three possible ways to do this might be (1) split the > string by '_' using strsplit and paste the first of the resulting variables > into a new column, but I have been unable to do this for each row of my data > frame in turn (trying to use apply); (2) split the column into two based on > '_', but I am not sure if this is possible; (3) use a regular expression to > return the substring up to the '_', but I am unsure how to make a regular > expression return the substring it matches to in R. > > Any ideas on all three counts would be gratefully recieved. ______________________________________________ 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.
