[Rd] data frame subscription operator
vdergachev at rcgardis.com
Wed Nov 8 23:36:44 CET 2006
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 .
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..
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