Probably something along the following lines: > x <- c( 46, 125 , 36 ,193, 209, 78, 66, 242 , 297 , 45) > sorted <- c(36 , 45 , 46, 66, 78, 125,193, 209, 242, 297) > tapply(sorted, INDEX = (seq_along(sorted) - 1) %/% 3, FUN = mean) 0 1 2 3 42.33333 89.66667 214.66667 297.00000
Hope this helps, Giovanni On Tue, 2012-04-03 at 08:47 -0400, Val wrote: > Hi all, > > Assume that I have the following 10 data points. > x=c( 46, 125 , 36 ,193, 209, 78, 66, 242 , 297 , 45) > > sort x and get the following > y= (36 , 45 , 46, 66, 78, 125,193, 209, 242, 297) > > I want to group the sorted data point (y) into equal number of > observation per group. In this case there will be three groups. The first > two groups will have three observation and the third will have four > observations > > group 1 = 34, 45, 46 > group 2 = 66, 78, 125 > group 3 = 193, 209, 242,297 > > Finally I want to calculate the group mean > > group 1 = 42 > group 2 = 87 > group 3 = 234 > > Can anyone help me out? > > In SAS I used to do it using proc rank. > > thanks in advance > > Val > > [[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. -- Giovanni Petris <gpet...@uark.edu> Associate Professor Department of Mathematical Sciences University of Arkansas - Fayetteville, AR 72701 Ph: (479) 575-6324, 575-8630 (fax) http://definetti.uark.edu/~gpetris/ ______________________________________________ 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.