[PD] Analog/good-sounding oscillators in PD

Mathieu Bouchard matju at artengine.ca
Thu Apr 13 05:38:58 CEST 2006


On Fri, 7 Apr 2006, Frank Barknecht wrote:

> 3.audio.examples/E05.chebychev.pd is the waveshaping example in
> Miller's docs. 

You may also test with *any* Chebyshev polynomial using the following 
polynomial:

[min 1]
 |
[max -1]
 |
[expr cos($f2*acos($f1)]

the min max are required because tabread4 needs one sample over each side 
of the [-1;1] range, but that's not permitted by acos.

This expr *really* acts like a polynomial when used in the [-1;1] range.
That's the same formula that Chebyshev used to find the coefficients for
the polynomials.

 _ _ __ ___ _____ ________ _____________ _____________________ ...
| Mathieu Bouchard - tél:+1.514.383.3801 - http://artengine.ca/matju
| Freelance Digital Arts Engineer, Montréal QC Canada




More information about the Pd-list mailing list