Hi: Here's another way:
c1<-c(1,2,3,2,2,3,1,2,2,2) c2<-c(5,6,7,7,5,7,5,7,6,6) c3<-rnorm(10) x <- data.frame(c1 = factor(c1), c2 = factor(c2), c3) x <- transform(x, mean = ave(c3, c1, c2, FUN = mean)) Yet another with function ddply() in package plyr: ddply(x, .(c1, c2), transform, mean = mean(c3)) HTH, Dennis On Fri, Feb 25, 2011 at 7:14 AM, zem <zmanol...@gmail.com> wrote: > > Yeah, you are right > i want to post an short example what i want to do .. and in the meantime i > solved the problem ... > but here is: > i have something like this dataframe: > c1<-c(1,2,3,2,2,3,1,2,2,2) > c2<-c(5,6,7,7,5,7,5,7,6,6) > c3<-rnorm(10) > x<-cbind(c1,c2,c3) > > x > c1 c2 c3 > [1,] 1 5 0.08279036 > [2,] 2 6 0.59135988 > [3,] 3 7 1.45520468 > [4,] 2 7 -1.70094640 > [5,] 2 5 0.13065228 > [6,] 3 7 -1.12080980 > [7,] 1 5 0.42779354 > [8,] 2 7 -1.53111972 > [9,] 2 6 0.29299987 > [10,] 2 6 -0.01602095 > > #whith aggregate i receive this: > >aggregate(x[,3],list(x[,1],x[,2]),mean) > Group.1 Group.2 x > 1 1 5 0.2552920 > 2 2 5 0.1306523 > 3 2 6 0.2894463 > 4 2 7 -1.6160331 > 5 3 7 0.1671974 > > > and the problem was that i was grouping by 2 columns, so i couldn't copy > the > result to x. > > the solution was i made another column with paste(x[,1],x[,2],sep="_") > and then i used the solution from this link: > http://tolstoy.newcastle.edu.au/R/help/06/07/30184.html > so i solved my problem > > Ivan, many thanks for your support and quik responses! :) > > -- > View this message in context: > http://r.789695.n4.nabble.com/group-by-in-data-frame-tp3324240p3324608.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. > [[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.
