[Numpy-discussion] The NumPy Mandelbrot code 16x slower than Fortran
Dag Sverre Seljebotn
d.s.seljebotn at astro.uio.no
Mon Jan 23 04:04:36 EST 2012
On 01/23/2012 05:35 AM, Jonathan Rocher wrote:
> Hi all,
>
> I was reading this while learning about Pytables in more details and the
> origin of its efficiency. This sounds like a problem where out of core
> computation using pytables would shine since the dataset doesn't fit
> into CPU cache: http://www.pytables.org/moin/ComputingKernel. Of course
> C/Cythonizing the problem would be another good way...
Well, since the data certainly fits in RAM, one would use numexpr
directly (which is what pytables also uses).
Dag Sverre
>
> HTH,
> Jonathan
>
> 2012/1/22 Ondřej Čertík <ondrej.certik at gmail.com
> <mailto:ondrej.certik at gmail.com>>
>
> On Sun, Jan 22, 2012 at 3:13 AM, Sebastian Haase
> <seb.haase at gmail.com <mailto:seb.haase at gmail.com>> wrote:
> > How does the algorithm and timing compare to this one:
> >
> >
> http://code.google.com/p/priithon/source/browse/Priithon/mandel.py?spec=svna6117f5e81ec00abcfb037f0f9da2937bb2ea47f&r=a6117f5e81ec00abcfb037f0f9da2937bb2ea47f
> <http://code.google.com/p/priithon/source/browse/Priithon/mandel.py?spec=svna6117f5e81ec00abcfb037f0f9da2937bb2ea47f&r=a6117f5e81ec00abcfb037f0f9da2937bb2ea47f>
> >
> > The author of original version is Dan Goodman
> > # FAST FRACTALS WITH PYTHON AND NUMPY
>
> Thanks Sebastian. This one is much faster ---- 2.7s on my laptop with
> the same dimensions/iterations.
>
> It uses a better datastructures -- it only keeps track of points that
> still need to be iterated --- very clever.
> If I have time, I'll try to provide an equivalent Fortran version too,
> for comparison.
>
> Ondrej
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>
>
> --
> Jonathan Rocher, PhD
> Scientific software developer
> Enthought, Inc.
> jrocher at enthought.com <mailto:jrocher at enthought.com>
> 1-512-536-1057
> http://www.enthought.com <http://www.enthought.com/>
>
>
>
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