[PD] phasor~ and osc~ right inlet: exact timing

Mike Moser-Booth mmoserbooth at gmail.com
Sun Apr 18 17:42:45 CEST 2010

Hey guys,

Thank you very much for checking this out. I'm glad you guys like.

Frank, I was looking at your comparison patch and noticed you took the 
[+~ 2] out. The reason I put this in is because [wrap~] converts 0 to 1, 
so if you reset the phase to 0 you'll end up starting at the end instead 
of the beginning. And I did [+~ 2] instead of [+~ 1] because thought I 
read somewhere that [phasor~] actually goes all the way up to 1 instead 
of just before it. I don't know if that's actually true or not, though, 
but I figured adding 2 is easier than looking at the source. ;-)

Thanks again,

Roman Haefeli wrote:
> On Sun, 2010-04-18 at 11:25 +0200, Frank Barknecht wrote:
>> On Fri, Apr 16, 2010 at 08:19:09PM +0200, Frank Barknecht wrote:
>>> Mike's trick then is to take a snapshot~ of the original phasor at the
>>> moment of the desired phase resetting.  If you substract that value from
>>> the original phasor, you get a phasor~ shifted up or down just by the
>>> value it had when the phase was last reset.
>>> Now you can add in the desired phase value again to get a wrap-phasor that is
>>> out of sync to the original phasor in exactly the desired fashion.
>> Actually I meant two write "take a [samphold~] of the original phasor".
>> Taking a snapshot~ or rather, a vsnapshot~ is something I have also
>> tried, but it gives the wrong results. See attached example for a
>> comparison of [vsnapshot~]->[vline~] with Mike's [samphold~] solution
>> (which I simplified a bit). Lesson to learn:  [vsnapshot~]->[vline~]
>> won't do what you may expect it to do.
> Before this thread was started, I also was thinking of a [vsnapshot~]
> based solution. But I didn't even start to try to implement it, because
> it includes a loop (message -> audio -> message) that will certainly
> introduce a latency, which breaks the goal of accuracy completely. 
> I find Mike's loopless [samphold~] based solution very elegant.
> Roman
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