Hi, Here's one option:
dat <- read.table(text = "Units Var1 Var2 Var3 1 B 2 2 1 C 1 3 2 D 3 3 2 C 2 1 2 A 1 2 3 C 2 1 3 A 1 3 4 B 3 3 4 C 2 2 4 A 1 1", header = TRUE) dat2 <- dat[as.logical(ave(dat$Var2, dat$Units, FUN = function(x) x == max(x))), ] dat2 Cheers, Josh On Mon, Jan 16, 2012 at 2:13 PM, Felipe Nunes <felipnu...@gmail.com> wrote: > Dear all, > > I have a data set in which the same unit appears 2 or 3 or 4 times. I need > to aggregate this data to maintain only one unit by row. But I need to do > that based on a comparison between the values of such units. I can't find a > function to help me on that. I appreciate any help. Below I provide an > example of what I want: > > This is my data: > > Units Var1 Var2 Var3 > 1 B 2 2 > 1 C 1 3 > 2 D 3 3 > 2 C 2 1 > 2 A 1 2 > 3 C 2 1 > 3 A 1 3 > 4 B 3 3 > 4 C 2 2 > 4 A 1 1 > > I want to produce a new data in which I keep, for each unit, the row with > max number for Var2. For instance, > > Units Var1 Var2 Var3 > 1 B 2 2 > 2 D 3 3 > 3 C 2 1 > 4 B 3 3 > > Thanks, > > > *Felipe Nunes* > CAPES/Fulbright Fellow > PhD Student Political Science - UCLA > Web: felipenunes.bol.ucla.edu > > [[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. -- Joshua Wiley Ph.D. Student, Health Psychology Programmer Analyst II, Statistical Consulting Group University of California, Los Angeles https://joshuawiley.com/ ______________________________________________ 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.
