Dear Jacques, I believe you need dat ordered by ind and y before you apply your solution, right?
Sincerely, Carlos J. Gil Bellosta http://www.datanalytics.com http://www.data-mining-blog.com Quoting Jacques VESLOT <[EMAIL PROTECTED]>: > do.call(rbind,lapply(split(dat, dat$ind), function(x) x[c(1,nrow(x)),])) > ------------------------------------------------------------------- > Jacques VESLOT > > CNRS UMR 8090 > I.B.L (2ème étage) > 1 rue du Professeur Calmette > B.P. 245 > 59019 Lille Cedex > > Tel : 33 (0)3.20.87.10.44 > Fax : 33 (0)3.20.87.10.31 > > http://www-good.ibl.fr > ------------------------------------------------------------------- > > > Mauricio Cardeal a écrit : >> Hi all >> >> Sometime ago I asked for a solution about how to aggregate data and the >> help was wonderful. Now, I´d like to know how to extract for each >> individual case below the first and the last observation to obtain this: >> >> ind y >> 1 8 >> 1 9 >> 2 7 >> 2 11 >> 3 9 >> 3 10 >> 4 8 >> 4 5 >> >> # Below the example: >> >> ind <- c(1,1,1,2,2,3,3,3,4,4,4,4) >> y <- c(8,10,9,7,11,9,9,10,8,7,6,5) >> dat <- as.data.frame(cbind(ind,y)) >> dat >> attach(dat) >> mean.ind <- aggregate(dat$y, by=list(dat$ind), mean) >> mean.ind >> >> Thanks >> Mauricio >> >> ______________________________________________ >> [email protected] 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. >> > > ______________________________________________ > [email protected] 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. > ______________________________________________ [email protected] 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.
