---------- Forwarded message ---------- From: Mike McGonagle mjmogo@gmail.com Date: Thu, Mar 20, 2008 at 7:18 PM Subject: Re: [PD] I'm stuck in a corner, please help! RE: [delta~] object To: Andy Farnell padawan12@obiwannabe.co.uk
Andy,
If it is a book about PD, why not add a tutorial for writing externals, and then show how [delta~] is written (with nods to the original author?), and then use that external? By the way, if you are looking for a Proof Reader, I would be more than happy to offer my services...
Mike
On Thu, Mar 20, 2008 at 6:40 PM, Andy Farnell padawan12@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:
Drop three of the most interesting exercises from the textbook.
Change my policy and make the textbook require pd-extended on account
of only _one_ object!
- Find a vanilla replacement for [delta~] that is simple. (less than
three objects)
Convince Miller to include [delta~] in vanilla
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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Mike McGonagle