Your data didn't come through with the html stripping but either unique() or duplicated() should get you where you need to be.
Michael On Mon, Oct 31, 2011 at 12:25 PM, yan liu <yanliu...@gmail.com> wrote: > Hi, > > I have a matrix like this, two columns: a, b > > a b c1 21 c2 19 c2 20 c2 20 c4 25 c5 18 c5 18 > how to prepare a new matrix removing the rows with repeated units in b > columns, like there are two 20 and two 18 in b column (others are unique in > b col). I wanna a pure matrix with one 20 and one 18. > > Thanks a lot! > > Yan > > [[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. > ______________________________________________ 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.
