David, thanks a lot! I tried x[-1] myself but forgot to delete 'group' from the keyby statement - this explains why it did not work for me. This is amazing - just 2 lines instead of my many-many. Great learning! Dimitri
On Tue, Jul 17, 2012 at 10:49 PM, David Freedman <d...@cdc.gov> wrote: > Honestly, I wasn't sure what you wanted to do with 'group'. Here it is with > the 'group' variable deleted > > library(data.table) > dt=data.table(x[,-1]) > dt[,lapply(.SD, function(x)weighted.mean(x,myweight)), keyby='myweek'] > > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/weighted-mean-by-week-tp4636814p4636828.html > Sent from the R help mailing list archive at Nabble.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. -- Dimitri Liakhovitski marketfusionanalytics.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.
