On 15-03-2013, at 10:56, Tammy Ma <metal_lical...@live.com> wrote: > Hi, > > I have data frame like this: > > Product Price Year_Month PE > A 100 201012 -2 > A 98 201101 -3 > A 97 201102 -2.5 > B 110 201101 -1 > B 100 201102 -2 > B 90 201103 -4 > > > How can I achieve the following result using R: > Product Price Year_Month PE > A 97 201102 -2.5 > B 90 201103 -4 >
Another option is to use aggregate like this aggregate(x, by=list(x$Product), FUN=function(z) tail(z,1))[,-1] or aggregate(. ~ Product, data=x, FUN=function(z) tail(z,1)) Berend ______________________________________________ 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.
