Try this: xtabs(value ~ city + brand, mydf)
On Wed, Nov 3, 2010 at 6:23 PM, Dimitri Liakhovitski < dimitri.liakhovit...@gmail.com> wrote: > Hello! > > I have a data frame like this one: > > > mydf<-data.frame(city=c("a","a","a","a","a","a","a","a","b","b","b","b","b","b","b","b"), > brand=c("x","x","y","y","z","z","z","z","x","x","x","y","y","y","z","z"), > value=c(1,2,11,12,111,112,113,114,3,4,5,13,14,15,115,116)) > (mydf) > > What I need to get is a data frame like the one below - cities as > rows, brands as columns, and the sums of the "value" within each > city/brand combination in the body of the data frame: > > city x y z > a 3 23 336 > b 7 42 231 > > > I have written a code that involves multiple loops and subindexing - > but it's taking too long. > I am sure there must be a more efficient way of doing it. > > Thanks a lot for your hints! > > > -- > Dimitri Liakhovitski > Ninah Consulting > www.ninah.com > > ______________________________________________ > 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.