On Wednesday 08 November 2006 11:41 am, Gabor Grothendieck wrote: > .subset and .subset2 are equivalent to [ and [[ except that > dispatch does not take place. See ?.subset >
Thank you Gabor ! I made an experiment and got rid of class(x) <- attr(x, "row.names") <- NULL while replacing all occurrences of x[ and x[[ with .subset and .subset2 . Results: X<-A[,1] is now instantaneous, as it should be. X<-A[1,1] is faster for data frames with many columns, but still appears to make a copy of A[,1] before indexing. Not sure why.. thank you Vladimir Dergachev ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel