## Mathematical problem (syncing variable speed phasors)

Sep 06 2020 | 6:15 pm
Hi all! I 'm just stuck with a mathematical problem i need some help to solve. Let's see if i can explain it properly:
I have 2 synced phasors, at the same frequency and phase.
At some arbitrary moment, i want phasor A to accelerate for 4 seconds until it arrives to, let's say, double the frequency of phasor B.
Phasor A stays at this new higher frequency for some time, and it decelerates for 4 seconds until it reaches again the original frequency.
The problem comes because i want that when phasor A finishes deceleration, it matches the exact phase of phasor B. This obviously means that the deceleration has to start in a specific moment in time to be able to catch phasor B in its exact phase.
I think this is related to uniformly accelerated linear motion equations, and might imply the use of derivative calculous?
I want to use this to sync 3 vertical scrolling image slides, where i want each of the 3 scrolls to alter its frequency from time to time, but then going back to normal speed and matching the exact position of the other 2 scrolls.
I imagine this might be useful to sync audio loops too: having 2 rhythm loops synced, and one starts to accelerate until it reaches double the frequency of the other one, and then going back to normal and catching phase again (beat or bar synced)
Has anyone done something like this and can point out possible solutions?My calculous is pretty oxidized and i don't know how to approach the problem....

• Sep 06 2020 | 7:48 pm
unlike for data rate, which is really nasty... https://cycling74.com/forums/synced-tempo-change-like-ritardandoaccelerando ...it is quite simple for signals. you just have to take care that ramp time, base speed and end speed are in a certain relation to each other. your personal sunday play package: click the numbers and find out the rule(s)!
• Sep 06 2020 | 9:27 pm
Whoa! Thanks for your help Roman! It's funny to see there's another actual thread revolving around a similar issue! I tried to adapt your example to my needs, but again, i get stuck at figuring out this relationship between the base frequency of the phasors and the time the speed keeps altered and ramping up/down. On your example, with the phasor at 1hz and the ramp times at 2000ms everything worked great... But for my needs, i'm working at a base frequency of 0.03125hz, and ramp times need to be recalculated. In addition, i need to keep the frequency higher for a while (doesn't need to be an exact number, but ideally close to a a cycle of the base speed (around 32seconds minus the accel/decel time)
I'm afraid my dumbness is so swollen right now...
• Sep 06 2020 | 11:21 pm