[PD] Infinite and NaN float values?

Mathieu Bouchard matju at artengine.ca
Mon Aug 16 21:40:21 CEST 2010

On Mon, 16 Aug 2010, Andy Farnell wrote:

> Yep, there's a few synthesis techniques like
> 1/1+cos(x^n)

eee, do you mean 1/(1+cos(pow(x,n))), or do you mean 1/(1+pow(cos(x),n)) ?

and then, why would it want a zero there ?

> Not sure to what extent it's still true but NaN used to royally screw up 
> some versions of Jack and ALSA, requiring a complete restart of the 
> audio stack.

I'm speculating that if they run an unprotected equivalent of [lop~] or 
[hip~] in their own code at any point, it sets the feedback variable to 
something that will never fade out, and then everything gets clipped to +1 
or -1. (do they have recursive filters in there ?)

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| Mathieu Bouchard, Montréal, Québec. téléphone: +1.514.383.3801

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