[Numpy-discussion] String sort
Wed Feb 13 04:34:46 CST 2008
A Tuesday 12 February 2008, Charles R Harris escrigué:
> On Feb 12, 2008 9:07 AM, Francesc Altet <firstname.lastname@example.org> wrote:
> > * The newqsort performs the best on all the platforms we have
> > checked (ranging from a 5% of improvement on Opteron/SuSe, up to
> > 3.8x with some Pentium4/Ubuntu systems).
> The 3.8 is amazing, isn't it? I've found that the performance also
> depends on whether I initialize the strings with random or empty.
> With the random initialization the new sort is ~2x faster. That's
> fedora 8, core duo, 32 bit OS, gcc 4.1.2.
Well, for me, a 3.8x (or even a 2x for that matter) of improvement is
less amazing once you know that there is a flaw in C qsort for most of
Linux distros around. Neither Windows, MacOSX or certain versions of
Linux (namely, SuSe 10.3) does reflect such a large difference in
I'd say that newqsort that is to be included in next release of NumPy
would be just a 10% better than using a sane implementation of C qsort.
And, while a 10% is not as amazing than a 380%, the great news is that
newqsort will provide first-class performance even to people having the
flawed C qsort on their machines (which apparently are much more that I
>0,0< Francesc Altet http://www.carabos.com/
V V Cárabos Coop. V. Enjoy Data
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