> Note that in the documentaton ?"[.data.table" where I say that 'by' is slow, > I mean relative to how fast it could be. Its seems, in this specific > example anyway, and with the code posted so far, to be significantly faster > than sqldf and plyr.
Of course the best of both worlds would be to use data table within plyr to get both speed and a consistent syntax for other types of split-apply-combine tasks. Hadley -- http://had.co.nz/ ______________________________________________ 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.
