[nightcracker]

Originally Posted by Hati-EK this is right - at 120fps the function is more fluently ... as the frequency is another - 1/120 vs. 1/10 - but the sampling frequency is 0.25 - so at 120fps it would take 30frames to match the sampling frequency - with 10fps it would take 2.5frames (3frames as there are NO floating frames) 120 fps: approx. elapsed = 1/120 = 0.0083333333333333s per OnUpdate ( called frequence g in rest of text ) sampling frequency f = 0.25 Hz (or 4fps = 1/4Hz) f = 30*g so every 30-frame((n*30)%120, n<-N{0,1,2,..) the SinusFunction() is called - at this point it works fine now think of ppl having an average fps of not 120fps - like you said 10fps drawing frequency h = 1/10 Hz sampling frequency f = 0.25 Hz resulting that point of collide = frame2.5, as there is no frame 2.5, it will take frame 3 (>=) time between frame2.5 and frame3 is t=((frame3-frame2)/2); frame2 is drawn after 0.2s, frame3 after second 0.3 (on time graph) - would result in a 0.05s delay so with last_update=0, it will result in: frame1 drawn - frame2 drawn - frame3 drawn - function fires, last_update is now 0 again - frame4 drawn - frame5 drawn (NOW it should fire again - but it doesn't as this is again 0.2 not 0.25) - frame6 drawn - function fires and again 3 frames required with last_update=last_update-sampling_frequency: frame1 drawn - frame2 drawn - frame3 drawn - function fires, last_update now is 0.05 - frame4 drawn (last_update 0.15) - frame5 drawn(last_update 0.25) - function fires correctly at (50% of fps as it should with sampling frequency 0.25 - and not at 60%) - frame 6 drawn - etc... and ppl have not an average fps of continuously 120fps (atleast not the most have)

What I say now I assuming you meant this:

do
	local last_update = 0
	local updater = CreateFrame("Frame", nil, UIParent)

	updater:Hide()
	updater:SetScript("OnUpdate",
			  function(self, elapsed)
				  last_update = last_update + .25

				  if last_update <= -.25 then
					  RunSinFunction()
					  last_update = 0
				  end
			  end)
end

Then that is equal to this:

do
	local start = 0
	local updater = CreateFrame("Frame", nil, UIParent)

	updater:Hide()
	updater:SetScript("OnUpdate", function(self, elapsed)
		start = start + .25
		SomeFrame:SetAlpha(math.sin(start))
	end)
end

Which means that the speed of the pulsing is determined by your FPS, not the amount of fluentness(is that a word?).