Hi there, I have a patch based on mmb's work [filterplot.mmb]. It plots frequency response from biquad coefficients. I have it attached, as a default, it is plotting the freq response of a bandpass filter.

So, I've been meaning to get the freq response of [vcf~] for a while now and I have the intuition that this patch may be adapted for that. [By the way, [vcf~] is basically a [cpole~] filter with the right coefficients and gain adjustment.

The heart of this freq response patch is the subpatch that deals with the Z-Transform (that's what I believe anyway). In this case, it originally deals with the Z-transform of the biquad filter, but I believe that if we change it to cpole's tranfer function it'll work to plot vcf's frequency response.

Right? Did I nail it? 

Well, if so... I've recently succeeded in getting the vcf's coefficients and gain to use them with [cpole~]. If you want you can check my patch attached. I'm generating the cpole's coeficients and everything, but the plotting subpatch still needs biquad coeficients to work. All that'd be missing is adapting the formula for the transfer function to cpole's.

cpole's help file says that its Transfer Function is: H(Z) = 1/(1 - aZ^-1)... so it doesn't seem even hard to do it so. Unfortunately I'm just a geeky musician with no math background and needed help getting down to it. I tried some stuff in the dark and failed.

thanks

Alex