aggregate() is not efficient. try by().
On Tue, Dec 25, 2012 at 11:34 AM, Martin Batholdy <batho...@googlemail.com>wrote: > Hi, > > > I need to aggregate rows of a data.frame by computing the mean for rows > with the same factor-level on one factor-variable; > > here is the sample code: > > > x <- data.frame(rep(letters,2), rnorm(52), rnorm(52), rnorm(52)) > > aggregate(x, list(x[,1]), mean) > > > Now my problem is, that the actual data-set is much bigger (120 rows and > approximately 100.000 columns) and it takes very very long (actually at > some point I just stopped it). > > Is there anything that can be done to make the aggregate routine more > efficient? > Or is there a different approach that would work faster? > > > Thanks for any suggestions! > > ______________________________________________ > 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. > -- ============================== WenSui Liu Credit Risk Manager, 53 Bancorp wensui....@53.com 513-295-4370 ============================== [[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.
