Thanks for your interest!
> > Known issues:
> > - The algorithm to generate the poles in legendap is not numerically stable
> > and efficient; I proceed exactly like in the above pdf and there is an
> > inevitable loss of precision when finding the roots of the polynomial. Using
> > orders of 30 or above yields erratic but stable filters, and that may happen
> > for orders below 30 but I didn't verify this.
>
> Is this something you would want to look at addressing automatically
> in the function or mentioning in the documentation?
If I knew a way to generate directly the poles without resorting to generate a poly then finding the roots it would not have this problem. For the moment I'd just document this behavior.
> > - legendap and legendf would require the appropriate test script in the
> > footer.
>
> Is that something you can add as part of your contribution?
>
> Have you documented the functions using Texinfo format?
I don't know how that automatic testing facility works, I have to look at Octave's manuals. The legendf function need some edits in its documentation and legendap just needs documentation, ahah! I just don't know how the docs are generated, but at least I know LaTeX so I know I can do this.
> > The functions would be released using the GPL licence.
>
> The signal package is licensed GPLv3, is that ok?
This should be fine.
> Yes, your contribution is welcome. If you are familiar with mercurial,
> you can fork the repository from
>
>
http://hg.code.sf.net/p/octave/signal>
> and send a pull request to pull changesets from your clone hosted
> somewhere on a public server. Or you can simply submit files to the
> Octave patch tracker at
>
>
https://savannah.gnu.org/patch/?func=additem&group=octave
I know git and svn, and mercurial seems "close enough" to git. But I might just submit the files to the patch tracker, it seems simplier.
> Thanks for your interest in helping to improve the signal package!
That's alright, IMO it is a good way to "give back" to the Open Source community.
―
James-Adam Renquinha Henri