Re: octave vs. matlab vectorization

[matt]

Hi John,

First let me take this opportunity to thank you for all the great  
work you have done on Octave over the years. I am using it constantly  
and couldn't be happier.

On vectorization issue, I was staggered for two reasons. First, I  
couldn't believe that Matlab had "given up" on software  
vectorization. Did they tell anyone?! I only really care because I  
sometimes send Octave code to Matlab users; it's nice to know what  
the differences are. The second reason is that I was surprised the  
JIT compiler worked as well as it did--to use Jaroslav's quote, the  
elephant can dance.

Having said that, James found the vectorized code ran 5x faster on  
his Matlab--so who knows what is going on? Perhaps the Matlab  
compiler is cheating?

Anyway, many thanks again for Octave.

Best,

Matt.

On 14 Sep 2009, at 18:29, John W. Eaton wrote:

> On 14-Sep-2009, matt wrote:
>
> | ah, no! code 1 was *faster* under matlab! the ratio is 0.19:1
> |
> | i find this result quite staggering.
>
> Why?  As someone else already explained, Matlab has a JIT compiler
> that can, in some cases at least, compile loops into native code so
> that it runs faster and Octave does not have a JIT compiler.
>
> jwe