On 10/18/2012 05:16 PM, Joza wrote:

> As regards the fsolve function, is it possible to specify the x-convergence

> test for EACH ITERATION? I know can input the absolute convergence error for

> "TolX", but I would rather test each iteration, which will depend on the

> value obtained in the previous iteration. Is that possible?

You can very simply modify almost all(*) Octave built-in functions,

because they are often implemented in Octave/Matlab language. If you

'type fzero', you'll see the implementation of the function 'fzero'; you

can edit it to do what you want and redefine fzero() or create my_fzero().

>

> I'm also curious, does it happen often that simple self-made algorithms can

> provide better answers than Octave's built-in functions?

For a specific case, yes, of course---the Octave built-ins are by design

handling a general case, so if you can figure out a shortcut that works

better for your specific case, it'll beat the built-in.

I don't know whether it 'happens often', but new algorithms do appear

even though a lot of smart people worked for a long time to implement

Octave's built-ins. If you can think of a self-made algorithm that's

better than the current one, please contribute it---that's the beauty of

Free Software.

(*) some Octave functions are implemented in C/C++/Fortran; it's

possible to modify them as well but it's a little more involved.

_______________________________________________

Help-octave mailing list

[hidden email]
https://mailman.cae.wisc.edu/listinfo/help-octave