Here is another way: aggregate(.~ A + B, FUN = length, x)
On Tue, Apr 3, 2012 at 3:26 PM, Steven Raemaekers <s.raemaek...@sig.eu>wrote: > Hi, > > I have a query which I would like to translate into R, but I do not know > how to do it in an easy way. > Assume a data frame has columns A, B and C: > > A B C > 1 1 3 > 1 1 4 > 1 1 5 > 1 2 6 > 1 2 7 > 1 3 8 > > The query is as follows: > > select A, B, count(*) > from data.frame > group by A, B > order by count(*) desc > > How do I translate this into R statements in such way that the result is a > data frame structured as follows: > > A B count(*) > 1 1 3 > 1 2 2 > 1 3 1 > > Thanks, > > Steven > ______________________________________________ > 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. > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O [[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.
