Walsh functions

[Eli Brandt]

Neil Johnson wrote:
>      Me, I tinker about with odds and ends.  Anyone want a discussion on 
>      additive synthesis using Walsh functions...?

Actually, yeah.  You wrote an interesting tutorial on Walsh functions
a while back, but I haven't gotten around to playing with them.  Have
you made any interesting noises?

If you'd care to spoon-feed a bit further, I'm curious how you do
analysis into this basis set.  Like, I can take a sound, FFT it, and
resynthesize from sinusoids, which gives me a starting point for
manipulation.  Is there an equivalent here?  (For example, how did you
get that decomposition of a sine into W_i's?  I know there's a thing
called a "Hadamard transform", which is a promising _name_, but...)

btw, there are a couple of references from the 80s in:
http://www.astro.virginia.edu/~eww6n/math/WalshFunction.html

-- 
     Eli Brandt  |  eli+ at cs.cmu.edu  |  http://www.cs.cmu.edu/~eli/