[R] the first and last case

From: Mauricio Cardeal <mcardeal_at_ufba.br>
Date: Wed 26 Jul 2006 - 22:22:19 EST

Hi all

Sometime ago I asked for a solution about how to aggregate data and the help was wonderful. Now, IŽd like to know how to extract for each individual case below the first and the last observation to obtain this:

ind y
1 8
1 9
2 7
2 11
3 9
3 10
4 8
4 5

# Below the example:

ind <- c(1,1,1,2,2,3,3,3,4,4,4,4)
y <- c(8,10,9,7,11,9,9,10,8,7,6,5)
dat <- as.data.frame(cbind(ind,y))

mean.ind <- aggregate(dat$y, by=list(dat$ind), mean) mean.ind


R-help@stat.math.ethz.ch 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. Received on Wed Jul 26 22:31:32 2006

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.1.8, at Thu 27 Jul 2006 - 00:16:52 EST.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.