[PD] from signal to VU

Mathieu Bouchard matju at sympatico.ca
Wed Feb 12 17:41:59 CET 2003


On Wed, 12 Feb 2003, Alex from Idoia wrote:
> I am trying to use VU to measure the output of a signal.
> Is there an external like Max for [log~] or even [gain~]. ?
> I am trying to do the conversion db=log10(signal between 0 and 1)*20.
> Is there another way ?
> Thanks

Hi, I've been wondering about this: how does square root and logarithm
work for signals, because signals may get positive or negative... which
means taking square roots of negatives (imaginary result), taking logs of
numbers very close to zero (big negative result), equal to zero (minus
infinity result), smaller than zero (complex result)... I mean, the signal
itself is not complex, so how does applying square root and then applying
square get back to the original signal? (maybe the answer is: it
doesn't...)

(note: i have not been trying those objects myself...)

________________________________________________________________
Mathieu Bouchard                       http://artengine.ca/matju






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