Re: [Rd] Any interest in "merge" and "by" implementations specifically for sorted data?

From: Gabor Grothendieck <>
Date: Fri 28 Jul 2006 - 18:12:15 GMT

There was a performance comparison of several moving average approaches here:

The author of that message ultimately wrote the caTools R package which contains some optimized versions.

Not sure if these results suggest anything of interest here but it would be interesting if various base routines could be sped up to the point that a simple idiom is competitive with the caTools versions.

On 7/28/06, Kevin B. Hendricks <> wrote:
> Hi,
> I was using my installed R which is 2.3.1 for the first tests. I
> moved to the r-devel tree (I svn up and rebuild everyday) for my "by"
> tests to see if it would work any better. I neglected to retest
> "merge" with the devel version.
> So it appears "merge" is already fixed and I just need to worry about
> "by".
> On Jul 28, 2006, at 3:06 AM, Brian D Ripley wrote:
> > Which version of R are you looking at? R-devel has
> >
> > o merge() works more efficiently when there are relatively few
> > matches between the data frames (for example, for 1-1
> > matching). The order of the result is changed for 'sort = FALSE'.
> >
> Thanks,
> Kevin
> ______________________________________________
> mailing list
> mailing list Received on Sat Jul 29 04:15:01 2006

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