You might consider using the sqldf package. --------------------------------------------------------------------------- Jeff Newmiller The ..... ..... Go Live... DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live Go... Live: OO#.. Dead: OO#.. Playing Research Engineer (Solar/Batteries O.O#. #.O#. with /Software/Embedded Controllers) .OO#. .OO#. rocks...1k --------------------------------------------------------------------------- Sent from my phone. Please excuse my brevity.
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. ______________________________________________ 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.