Le 07/02/2011 18:40, Hans-Christoph Steiner a écrit :
On Feb 7, 2011, at 6:36 AM, cyrille henry wrote:
Le 07/02/2011 12:12, volker böhm a écrit :
On 07.02.2011, at 00:12, Hans-Christoph Steiner wrote:
I've started to write a GUI for generating biquad coefficients (something like
Max/MSP's [filtergraph~]). I've gotten the GUI interaction working well, now
I'm looking for the algorithms for generating a plot of the frequency response
of a given set of biquad coefficents? It'll end up being Tcl, but I can easily
read C, Csound, Java, Perl, Python, etc.
.hc
i've been using the attached js file to query amplitude and phase response of
biquad coeffs,
where the coeffs are expected to be of the form: y[n] = a0 * x[n] + a1 * x[n-1]
+ a2 * x[n-2] - b1 * y[n-1] - b2 * y[n-2] (like in maxmsp).
so, you'd have to rearrage the coeffs and turn the sign of the fb coeffs to
make it work with the pd biquad~.
or use bq~ from nusmuk-audio lib.
I like that [bq~] has audio inputs,
yep, that's very useful.
but can you send a list of them to the first inlet, like [biquad~]?
no, you need an unpack f f f f f...
i think to add this functionality should not be to hard, but do you really need
it?
C
.hc
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