The need comes from the PISA data. (http://www.pisa.oecd.org)
In the data there are many cases and each of them carries a numeric variable that signifies it's weight. In SPSS the command would be "WEIGHT BY" In simpler words here is an R sample ( What is get VS what i want to get ) > data.recieved <- data.frame( + kindergarten_attendance = factor(c(2,1,1,1), labels = c("Yes", "No")), + weight=c(10, 1, 1, 1) + ); > data.recieved; kindergarten_attendance weight 1 No 10 2 Yes 1 3 Yes 1 4 Yes 1 > > > > data.weighted <- data.frame( + kindergarten_attendance = factor(c(2,2,2,2,2,2,2,2,2,2,1,1,1), labels = c("Yes", "No")) ); > > > par(mfrow=c(1,2)); > plot(data.recieved$kindergarten_attendance,main="What i get"); > plot(data.weighted$kindergarten_attendance,main="What i want to get"); > tnx in advance Hed [[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.