[music-dsp] crossover filters for compressor

[Erik de Castro Lopo]

robert bristow-johnson wrote:

> oh, beside not wanting to shell out money for Mathematica (Derive,
> as it appeared about a decade ago, seemed like typical Windoze/PC
> inelegant), the real reason is that it's (for me) recreational
> mathematics

I agree on both points, Mathematica is too expensive and mathematics
is recreational. As a result of this I started writing my own 
computer algebra system a number of years ago:

    http://www.mega-nerd.com/erikd/Blog/CodeHacking/Ocaml/variant_types.html
    http://www.mega-nerd.com/erikd/Blog/CodeHacking/Ocaml/variant_types_code.html

and I've been slowly evolving and improving it as my needs grew. 
Its rather raw, and niggly to use and has complete lack of user
friendly features, but it usually does what I need it and if it
doesn't, it rarely takes long to extend it.

> is there any freeware or GNU counterpart?

There are at least two:

    http://maxima.sourceforge.net/
    http://wiki.axiom-developer.org/AboutAxiom

Cheers,
Erik
-- 
+-----------------------------------------------------------+
  Erik de Castro Lopo
+-----------------------------------------------------------+
"Every time you get a windows programmer asking you to write some
ass-backward workaround, think of it as a crack junkie asking you
to help stuff his pipe because his hands are too shaky."
-- Conrad Parker