From jmc at research.bell-labs.com  Wed Jun  4 18:09:07 2003
From: jmc at research.bell-labs.com (John Chambers)
Date: Wed Jun  4 23:09:29 2003
Subject: [Rd] Slow ttests in R-devel
References: <Pine.SOL.4.20.0306041545300.2682-100000@santiam.dfci.harvard.edu>
Message-ID: <3EDE5FF3.33206427@research.bell-labs.com>

Jeff Gentry wrote:
> 
> On Wed, 4 Jun 2003, John Chambers wrote:
> > There was a bug leading to non-caching of methods, in the r-patched code
> > from a few days ago.
> > A branch update would have put the changes into R-devel also.
> > The problem has been partly fixed in the current code committed to
> > R-patched (and some further fixes are in the works).
> 
> Actually, I realized that the particular R-pached I was using was from May
> 23.  I used my June 4th version of R-patched (aka R-1.7.1 beta) and it
> matches my June 4th version of R-devel, more or less:
> > system.time(genefilter(eset, gf))
> [1] 79.27  3.98 85.24  0.00  0.00
> 
> But, my 2003-05-23 version of r-patched produces a value that is roughly
> half of that.
> 
> Not sure if that helps out at all, but the current r-patched and r-devel
> is definitely slower in this then it was about a week and a half ago.
> 
> -J

Right.  The fix committed earlier today caught some of the non-caching,
but there are still some cases that are slipping through.  So it matters
"when" on June 4 the code was sampled.  But either way, not all the
problems are yet caught.

Fortunately, this has finally got me to instrument some checks that
method selection stays in the C code on the second time through an
expression.

By tomorrow morning, there should be a committed version that has no
unneccessary S-level method selection (at least on my tests, using Doug
& Saikat's lme4 code).  It would be very helpful if you could check
again after I send some mail around.

John

-- 
John M. Chambers                  jmc@bell-labs.com
Bell Labs, Lucent Technologies    office: (908)582-2681
700 Mountain Avenue, Room 2C-282  fax:    (908)582-3340
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[Rd] Slow ttests in R-devel
John Chambers