I withdraw this question, I was able to accomplish this by creating a new function.
Now if only I could get the by output into a dataframe... Mike On Wed, Feb 23, 2011 at 2:25 PM, Mike Schumacher <mike.schumac...@gmail.com>wrote: > Hello R folks, > > Reproducible code below - I'm trying to do a weighted mean by a factor and > can't figure it out. Thanks in advance for your assistance. > > Mike > > data<-data.frame(c(5,5,1,1,1), > c(10,8,9,5,3), > c("A","A","A","B","B")) > > names(data)<-c("COUNT","MEASURE","TYPE") > > ## UNWEIGHTED MEAN BY TYPE > by(data$MEASURE,data$TYPE,mean) > > ## WEIGHTED MEAN WITHOUT TYPE > weighted.mean(x=data$MEASURE,w=data$COUNT) > > ## WEIGHTED MEAN BY TYPE - DOESNT WORK > by(data$MEASURE,data$TYPE,weighted.mean(x=data$MEASURE,w=data$COUNT)) > > > > > -- > Michael Schumacher > Manager, Data and Analytics > ValueClick > mike.schumac...@gmail.com > > > > -- Michael Schumacher mike.schumac...@gmail.com 818-851-8638 [[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.