Sorry, my mistake. The thing is that the command return no results at all. However, when I just tried a simpler version of this (I had no capital letters or no spaces in the string), it worked fine. I cant figure it out, I think it all boils down to the fact that I'm no expert at regexp's...
On Aug 22, 5:53 pm, "R. Michael Weylandt" <michael.weyla...@gmail.com> wrote: > Can you say a little more about what you mean "it does not work"? I'd guess > you have a regular expression mistake and are probably getting more columns > than desired, but without an example, it's hard to be certain. > > Use dput() and head() to give a small cut-and-paste-able example. > > Michael > > > > > > > > > > On Mon, Aug 22, 2011 at 10:33 AM, Jay <josip.2...@gmail.com> wrote: > > Hi, > > > Let's say that I have a set of column names that begin with the string > > "Xyz". How do I extract these specific columns? I tried to do the > > following: > > > dataframe1[,grep("Xyz",colnames(dataframe1))] > > > But it does not work. What is wrong with my expression? > > > ______________________________________________ > > r-h...@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-h...@r-project.org mailing listhttps://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ 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.