[PD] algorithms for drawing filter response curves

[Hans-Christoph Steiner]

Ok, I got it working in a limited way as a Pd object and I was  
controlling my first filter against noise!  Good fun. You can still  
run the .tcl file as a standalone GUI for dev work.  Get it from my git:

https://github.com/pd-projects/filterview

It would be quite nice if the phase was drawn as a thin line over the  
magnatude graph.  What do you think?

.hc


On Feb 15, 2011, at 6:31 PM, Mike Moser-Booth wrote:

> Hey Hans,
>
> Here's an update of filterview. There are now procs for the  
> following filters:
>
> lowpass
> highpass
> allpass
> bandpass
> resonant
> peaking
> highshelf
> lowshelf
>
> I've added some lines to show the phase response (you have to  
> comment out line 135 and uncomment 136 to see it). I also adjust the  
> bandwidth calculations so the handles sit where they should (i.e.  
> -3dB for bandpass/notch/etc., 1/2 power for peaking/shelf).
>
> btw, the frequency axis is log-scaled, though it could probably be  
> improved a little. I sort of took a Pd approach to it by making an  
> mtof proc, so the x-axis gets scaled to linear midi notes and  
> converted to log-frequencies. :-) There might be a simpler way to do  
> it. It also doesn't go all the way down to 0 Hz, because doing that  
> with this approach causes the lowest frequencies to take up too much  
> of the graph. I think Max gets around it by using a more compressed  
> scale below 1-2 Hz.
>
> .mmb
>
> On Thu, Feb 10, 2011 at 12:39 AM, Mike Moser-Booth <mmoserbooth at gmail.com 
> > wrote:
> Sure, I can throw the others together. Now that one is done the rest  
> should fall into place pretty easily. It might take me a couple of  
> days to get to it, though.
>
> .mmb
>
> On Wed, Feb 9, 2011 at 11:47 PM, Hans-Christoph Steiner  
> <hans at at.or.at> wrote:
>
> That's awesome, thanks!  I committed it under your name:
>
> https://github.com/pd-projects/filterview
>
> I'd like to implement all of the relevant filters, which algorithms  
> should I use?  Or even better, perhaps you want to take a crack at  
> it while I figure out how to display the x/frequency on a log  
> scale :-D
>
> .hc
>
>
> -- 
> Mike Moser-Booth
> mmoserbooth at gmail.com
>
>
>
> -- 
> Mike Moser-Booth
> mmoserbooth at gmail.com
> <filterview.mmb.tcl.zip>





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