[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: speed of octave
From: |
David Bateman |
Subject: |
Re: speed of octave |
Date: |
Thu, 06 Sep 2007 23:53:22 +0200 |
User-agent: |
Thunderbird 1.5.0.7 (X11/20060921) |
frank wang wrote:
> while trying to find the speed of octave, scilab and matlab, I found
> the following test code and decided to run it on octave 2.9.13
> (window) and matlab 7.1a. The result shows that octave is 30 time
> slower than matlab.
>
> in Matlabe: tic; z=bench1(10); toc;
> Elapsed time is 0.015060 seconds.
>
> in octave: tic; z=bench1(10); toc;
> Elapsed time is 2.704300 seconds.
>
> function [z]=bench1(n)
> for i=1:n,
> for j=1:1000,
> z=log(j);
> z1=log(j+1);
> z2=log(j+2);
> z3=log(j+3);
> z4=log(j+4);
> z5=log(j+5);
> z6=log(j+6);
> z7=log(j+7);
> z8=log(j+8);
> z9=log(j+9);
> end
> end
> z = z9;
>
> Thanks
>
> Frank
Frank,
This is just an example of poorly written code and matlab is more
forgiving of poorly written code with their JIT compiler. Its silly to
talk about vectorization as the above makes no use of the iterations of
the loop, but read the document
http://www.mathworks.com/support/tech-notes/1100/1109.html
the advice here applies equally well to Octave. Yes matlab is faster
than Octave with for-loops, Use vectorization and that advantage
disappears. For the very few cases where you can't vectorize, convert
the code to a compiled language in the form of a mex- or oct-file.
D.
- Re: speed of octave, (continued)
- Re: speed of octave, John W. Eaton, 2007/09/13
- Re: speed of octave, Dmitri A. Sergatskov, 2007/09/13
- Re: speed of octave, John W. Eaton, 2007/09/13
- GPL (was: speed of octave), Francesco Potorti`, 2007/09/14
- Re: GPL, Søren Hauberg, 2007/09/14
- Re: speed of octave, David Bateman, 2007/09/14
- Re: speed of octave, Michael Goffioul, 2007/09/14
- Re: speed of octave, Tatsuro MATSUOKA, 2007/09/14
- Re: speed of octave, Michael Goffioul, 2007/09/14
- Re: speed of octave, Tatsuro MATSUOKA, 2007/09/14
Re: speed of octave,
David Bateman <=