Hi
r-help-boun...@r-project.org napsal dne 29.04.2010 05:56:23: > Hello, > > I have a data.frame: > name col1 col2 col3 col4 > AA 23 54 0.999 0.78 > BB 123 5 1 0.99 > AA 203 98 0.79 0.99 > > I want to get mean value data.frame in terms of name: > > name col1 col2 col3 col4 > > AA 113.0000 76.0000 0.8945 0.8850 > > BB 123.00 5.00 1.00 0.99 > > I tried to use by function: > > >aa<-by(test[,2:5], feature, mean) > I found aa is "by" function. > > class(aa) > [1] "by" > > how can I transfer aa to a data frame? use aggregate instead aa<-aggregate(test[,2:5], feature, mean) Regards Petr > > thanks > YU > > > > > > > [[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. ______________________________________________ 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.