[Rd] "by" speed improvement (PR#11064)

simon.debernard at altrabio.com simon.debernard at altrabio.com
Tue Apr 1 12:15:05 CEST 2008

Full_Name: Simon de Bernard
Version: 2.7.0 (44733)
Submission from: (NULL) (

"by" usually takes forever even on a "not so large" data structure.

If one can do with a matrix instead of a data.frame, defining by.matrix as
by.data.frame modified to convert data back to a data.frame in the "eval" call
improves speed by orders of magnitude (whatever that means ;-) )

I'd suggest defining the by.matrix function directly in R...

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