?? Row 4 has i = 2 and Measure_id =4 and therefore has value divided by the max of all values with that i and Measure_id, which is 1. Row 7 has i =2 and Measure_id =2, and so is divided by the max value in all rows with those values of i and Measure_id, which is 2. etc. So either you do not understand ave() or you are incorrectly stating what you want.
Incidentally, read ?ave, ?with and ?within. paste() is not needed and the call can be shortened to df <- within(df,newcol<-ave(value,i,Measure_id,FUN=function(x)x/max(x))) Finally, I suggest you learn to post in plain text (as the posting guide requests) to avoid possible mangling of your posts. Cheers, Bert Bert Gunter "Data is not information. Information is not knowledge. And knowledge is certainly not wisdom." -- Clifford Stoll On Sat, Nov 7, 2015 at 6:32 AM, Ragia Ibrahim <ragi...@hotmail.com> wrote: > Dear group, > kindly, I have the following data frame > > structure(c(2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, > 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1.5, 2, 1, 0, 2, 2, 1.5, > 0, 0, 1, 1, 2, 0, 1, 2), .Dim = c(15L, 3L), .Dimnames = list( > NULL, c("i", "Measure_id", "value"))) > > > > it has 3 coulmns > I used > df$newcoulmn <- ave(df$value, paste( df$i, df$Measure_id), FUN= > function(x) x/max(x) ) > > > to get x /max(x) and calc probability.. but I want to do that for each source > measure_id" separately that means that rows 4,7,13 ..their value should be > divided by 1.5 not 2.. > > rows 1,5,11 will be divided by 2 the max of their same group grouped by > measure id > how to make such grouping > > thanks in advance > Ragia > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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 -- To UNSUBSCRIBE and more, see 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.