[Tutor] improving speed using and recalling C functions

[Gabriele Brambilla]

I think I have Cython already installed with Anaconda.

How it works?

Thanks

Gabriele


2014-04-11 8:16 GMT-04:00 Albert-Jan Roskam <fomcl at yahoo.com>:

> ________________________________
> > From: Gabriele Brambilla <gb.gabrielebrambilla at gmail.com>
> >To: Danny Yoo <dyoo at hashcollision.org>
> >Cc: python tutor <tutor at python.org>
> >Sent: Friday, April 11, 2014 5:30 AM
> >Subject: Re: [Tutor] improving speed using and recalling C functions
> >
> >
> >
> >Hi Danny,
> >I followed your suggestion.
> >Tomorrow morning I will run this new version of the code.
> >
> >
> >Now using a sample of 81 elements (instead of 600000) the profile returns:
> >
> >
> >Thu Apr 10 23:25:59 2014    restats
> >
> >
> >         18101188 function calls in 1218.626 seconds
> >
> >
> >   Ordered by: internal time
> >   List reduced from 13 to 10 due to restriction <10>
> >
> >
> >   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
> >        1 1015.803 1015.803 1218.334 1218.334 skymaps5.py:44(mymain)
> > 18101000  202.490    0.000  202.490    0.000 {method 'write' of 'file'
> objects}
> >
> >
> >        1    0.292    0.292 1218.626 1218.626 <string>:1(<module>)
> >        6    0.029    0.005    0.029    0.005 {open}
> >        5    0.010    0.002    0.010    0.002 {method 'close' of 'file'
> objects}
> >
> >
> >       81    0.002    0.000    0.002    0.000 {method 'split' of 'str'
> objects}
> >       82    0.001    0.000    0.001    0.000 {zip}
> >        1    0.000    0.000    0.000    0.000 function_base.py:8(linspace)
> >        1    0.000    0.000    0.000    0.000
> function_base.py:93(logspace)
> >        5    0.000    0.000    0.000    0.000
> {numpy.core.multiarray.zeros}
> >
> >
> >Anyway I would like to try to speed it up using C functions (and maybe
> comparing the resuts of the two profile in the end)
> >How can I do it now? Can I use Cython?
>
> If you have a compiler installed already it's just easy_install cython.
> Writing Cython is not hard. That is, you easily get speed improvements.
> It's in a .pyx file and once you're done you generate the .c and .so/.dll
> files with a setup.py like below. Reason why I am posting this snippet is
> the way to generate an annotated html file of your cython code. The whiter,
> the more in C, the better. Yellow means stuff might still be improved more.
>
> * setup.py
> from distutils.core import setup
> from distutils.extension import Extension
> from Cython.Distutils import build_ext
> import Cython.Compiler.Options
> Cython.Compiler.Options.annotate = True   # <---- really handy
>
> setup(
>     cmdclass = {'build_ext': build_ext},
>     ext_modules = [Extension("myModule", ["myModule.pyx"])]
>
> )
>
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