Re: speed of octave

[Søren Hauberg]

frank wang skrev:
> 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.
You are working with such a short running program that I think the 
factor 30 is computed very non-robust. But, yes it is true that Octave 
is slower than matlab when working with loops. Matlab comes with a 
Just-in-Time compiler which can speed up the processing of loops quite a 
bit. Octave does not have such a feature. The main issue is that most of 
the people developing Octave aren't the kind of people that enjoy 
writing compilers. So if you know anybody who likes doing that, feel 
free to persuade them to work on a Just-in-time compiler for Octave :-)

Søren


> 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
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