Thank you Michael, However, this only provides the number of groups without a column label. Is there a way to have it give the count with the 'ID' label?
Regards, Charles On Fri, May 25, 2012 at 10:52 AM, R. Michael Weylandt < michael.weyla...@gmail.com> wrote: > length(unique(ID)) > > Michael > > On Fri, May 25, 2012 at 11:38 AM, Charles Determan Jr <deter...@umn.edu> > wrote: > > Hello, > > > > Simple question that I am stuck on and can't seem to find an answer in > the > > help files currently. I have a list which contains repeated ID's. I > would > > like to have R count the number of ID's. For example: > > > > ID=c(1,1,1,1,2,2,2,2,3,3,3,3) > > as.data.frame(ID) > > > > Clearly, there are 3 groups. How would I have R give me the summary: > > > > ID > > 3 > > > > Many thanks, > > Charles > > > > [[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.
