On Sun, Apr 18, 2010 at 01:28:02PM +0200, Matteo Sisti Sette wrote: > > 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. > > Very very interesting. Basically you have to take into account that > vsnapshot~ samples the signal with a delay of one block~ (and it > couldn't be otherwise), which renders it useless for the phasor~ > accurate reset application.
Pd alternates message and dsp computations. So the order here is: vsnapshot~ analyses dsp, then produces a message, then vline~ gets this one during the following message pass which is already too late to change its own signal result in the previous block. Duh. So while both vsnapshot~ and vline~ are subsample-accurate in a block, the combination is not. The samplehold~ approach also uses vline~ to schedule an accurate impulse, but as samphold~ works entirely in the signal realm, no delaying message pass is needed in between. Ciao -- Frank _______________________________________________ [email protected] mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
