[PD] algorithms for drawing filter response curves

[Mike Moser-Booth]

Awesome! I would like to be able to see the phase response, but since most
of the time the user is only interested in the magnitude response, I think
it should be something you can switch to with a message.

.mmb

On Wed, Feb 16, 2011 at 1:53 AM, Hans-Christoph Steiner <hans at at.or.at>wrote:

>
> 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>
>
>
>
>
>
>
>
> ----------------------------------------------------------------------------
>
> Programs should be written for people to read, and only incidentally for
> machines to execute.
>  - from Structure and Interpretation of Computer Programs
>
>


-- 
Mike Moser-Booth
mmoserbooth at gmail.com
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