> Yes. The culprit would seem to be interaction(), as in
>
>> x <- y <- z <- 1:999
>> i <- interaction(x,y,z, drop=TRUE)
> Error: cannot allocate vector of size 3.7 Gb
>
> which is happening due to the occurrence of three idvar variables. This
> works basically as interaction(x,y,z)[,drop=TRUE], i.e. it first creates a
> factor with 999^3 levels, and removes the empty levels afterward.
>
> In the absense of a better interaction(), you might try making your own
> single idvar as do.call("paste",tbl[,c("ID", "DATE1", "DATE2")]) or so.There's also ninteraction in the plyr package, which has been designed to generate a unique integer for each combination (while maintaining the original order of the data and any missing combinations) as efficiently as possible. It's much faster than interaction(..., drop = T) and I hope it would be faster than paste since it works with integers rather than strings. Hadley -- http://had.co.nz/ ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
