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Cake day: June 16th, 2023

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  • Pretty specific use case. A normal OS handleds time slicing and core assignment for processes and uses it’s judgement for that. So at any time your process can be suspended and you don’t know when you get your next time slice.

    Same with when you make wait calls. You might say wait 100ms but it may be much longer before your process gets to run again.

    In a real time OS if you have real time priority the OS will suspend anything else including it self to give you the time you request. It also won’t suspend you no matter how long you use the core.

    So if you need to control a process with extreme precision like a chemical manufacturing process, medical device, or flying a rocket where being 10ms late means failure they are required.

    However with great power comes great responsibility. You need to make sure your code calls sleep frequently enough that other tasks have time to run. Including things like file io or the gui.



  • Hugin@lemmy.worldtomemes@lemmy.worldIt's true.
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    2 months ago

    Yeah. The thing that made me “get” quaternions was thinking about clocks. The hands move around in a 2d plane. You can represent the tips position with just x,y. However the axis that they rotate around is the z axis.

    To do a n dimensional rotation you need a n+1 dimensional axis. So to do a 3D rotation you need a 4D axis. This is bassicly a quat.

    You can use trig to get there in parts but it requires you to be careful to keep your planes distinct. If your planes get parallel you get gimbal lock. This never happens when working with quats.


  • Hugin@lemmy.worldtomemes@lemmy.worldIt's true.
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    2 months ago

    No. It’s more what the previous poster said about encoding rotation. It’s just not a xyz axes. It’s current, charge, flux as axes. The trig is how you collapse the 3d system into a 2d or 1d projection. You lose some information but it’s more useful from a spefic reference.

    Without complex numbers you can’t properly represent the information.



  • Hugin@lemmy.worldtomemes@lemmy.worldIt's true.
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    2 months ago

    Yup. When you have a circuit that is not purely resistive the inductive or capacitive load causes the voltage and current to not be in phase. It looks like ohms law is being violated. However the missing part of the energy is in the imaginary component to be returned latter.