I have modified firls.m to include all types of FIRs plus HT and diff

[je suis]

Hello everyone

I managed to modify firls.m such that it now allows all types of FIRs,
I to IV, plus differentiators and Hilbert transformers. It also allows
forbidden filters, such as type II highpass, or similar. Just because
the result won't be a highpass it doesn't mean one should not allow
it: it is assumed that the user knows what he/she/it wants and how to
get it, the option is there; if not, maybe it's better to do something
else. Also, while I could verify in parallel the results in wxMaxima
(slightly more accustomed to), I don't know if the results are,
indeed, real, so it would be nice if someone who has access to Matlab
can verify this. Matlab's site also says something about a 1/f^2
weighting, I didn't bother with that, mainly because I don't know how
to do it, but also because Selesnick's paper says nothing about it.

Since I was not accustomed to Octave's language, I tried to adapt the
code by looking at other scripts, so I don't know how much on par with
your requirements is the result. I'll attach the file. If it proves to
be usable, it would be nice to update the current firls.m, given the
new choices of design. I have built upon the previous user's code,
both to avoid reinventing the wheel and to get more accustomed to
Octave's language. The name of the file is not the same as with the
function's name to avoid name clashes, but the definition inside is
firls(...).

Vlad

lsfir2.m
Description: application/vnd.wolfram.mathematica.package