[PD] I'm stuck in a corner, please help! RE: [delta~] object

[Charles Henry]

I'd say, you can't go wrong with fexpr~.  Works for any kind of
discrete time difference equations & has many amazing /creative uses.

Chuck

On Thu, Mar 20, 2008 at 6:40 PM, Andy Farnell
<padawan12 at obiwannabe.co.uk> wrote:
>
>  I have a problem, that is partly of my own making and need to air
>  this on the list for advice. This isn't a rant, just a frustrating situation.
>
>  As some of you know I have been working on a textbook for Pd for some time.
>  In the final stages and adding the practical exercises and the problem is this:
>
>
>  The book is completely for vanilla Pd to keep things simple and I really don't
>  want to change this.
>
>  I have three crucial exercises that use [delta~]
>
>  [delta~] does not exist in vanilla Pd
>
>  [delta~] must be recreated _EXACTLY_ as the external behaves.
>
>  It IS possible to recreate [delta~] exactly using [z~]
>
>  [z~] does not exist in vanilla
>
>  It is not, as far as I can see, possible to emulate [delta~] using
>  [rzero~] or any other signal domain method, in a way that doesn't
>  confuse the hell out of the reader or provide unsatisfactory results.
>
>  I am left with these options:
>
>
>  1) Drop three of the most interesting exercises from the textbook.
>
>  2) Change my policy and make the textbook require pd-extended on account of
>  only  _one_ object!
>
>  3) Find a vanilla replacement for [delta~] that is simple. (less than three objects)
>
>  4) Convince Miller to include [delta~] in vanilla
>
>  5) Convince Miller to include [z~] in vanilla
>
>
>  To the list: I'm hoping some bright spark will solve (3). Be warned, it isn't as
>  simple as it seems, AFAICS. [rzero~] should provide a differentiator response in
>  theory. In practice dealing with the offsets and scales ruins the whole show and
>  leads to over-complex and unstable patches. Using [biquad~] is extremely confusing
>  to most readers and I don't want to do this. You cannot obtain a single sample delay
>  using [delwrite~] as far as I know, if you can it certainly means [samplerate~] must
>  be added to all patches to make sure they run at different sr, which is mucho annoying.
>
>  To Miller: Please consider admitting [z~] or [delta~] (I actually prefer the former
>  because it is more educational to see differentiator built from sample delay)
>  into the vanilla distro. This would need to be time for release quite soon. I'm sure
>  it would greatly benefit Pd to do this.
>
>  Best regards 2 all,
>
>  Andy
>
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>
>  --
>  Use the source
>
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