[migiale]

Octave is Matlab clone, in fact Octave developers openly say that except for some special cases, any difference between Octave and Matlab is a bug.

The biggest difference between Matlab and Octave is JIT compiler in Matlab, which does incredibly good job at vectorizing simple (or sometimes even not-so simple) loops.

I think it's fair to say that Octave performance is very close to a Matlab in a pre-JIT time.

There's also a huge difference in toolboxes, profiling, sparse matrix operations, parallel computing and many-many more. In these areas I'm afraid Octave is light-years behind Matlab.

However, you still can do a lot of useful simple stuff with Octave and it's free! Matlab-like syntax is really, really cool then it comes to vectorized operations. So probably these two reasons determined Andrew Ng's choice of Octave as a main environment for ml-class. Huge win for Octave I guess. This might spur some interest in the development, attract new people to the product. I think it's a well-deserved success for John W Eaton and other people who develop(ed) Octave all these years.

[mturmon]

I agree with your take on Octave performance relative to Matlab. The Matlab parallel toolbox is getting more and more useful in a multicore world.

As you note, the Matlab profiler is very nice. You can zero in on the 80% of the 80/20 tradeoff very fast, during your usual development cycle. It's as simple as:

>> profile on >> do_something >> profile report

and you get a nice graphical/textual report on time usage in everything do_something called.

[muuh-gnu]

> in fact Octave developers openly say that

This is not true. They strive for Matlab language compatibility, but none of them refers to Octave as a "Matlab clone", nor are they working on cloning Matlab, nor was the project started to become a matlab clone. It is like calling Linux a "Unix clone".