Double Pendulum in fewer than 100 lines of JavaScript
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Double Pendulum in fewer than 100 lines of JavaScript
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Re: Double Pendulum in fewer than 100 lines of JavaScript
#2I remember when I first learned about the Lagrangian, and my mind was blown that really complicated problems could be wrangled so easily. Thanks for sharing this :)
Re: Double Pendulum in fewer than 100 lines of JavaScript
#3Cool.
Feature request: mount the pivot on a programmable cart. It'd be fun to write software to balance the double pendulum.
e.g. https://www.youtube.com/watch?v=B6vr1x6KDaY
and, balancing a triple pendulum: https://www.youtube.com/watch?v=cyN-CRNrb3E
Re: Double Pendulum in fewer than 100 lines of JavaScript
#4Would be even better, IMO, with a line in the simulation showing the path traced by each pendulum over time, preferably the arcs drawn could phase through different colours (and possibly decay in visibility). Nice work though.
Re: Double Pendulum in fewer than 100 lines of JavaScript
#5I remember when I first learned about the Lagrangian, and my mind was blown that really complicated problems could be wrangled so easily. Thanks for sharing this :)
Me too. Lagrangian mechanics are almost the only thing about my physics undergrad where I still recall thinking "wow this is awesome!"
Re: Double Pendulum in fewer than 100 lines of JavaScript
#6You can get a vigorous chaotic motion going with a high top mass, low bottom mass, and high angles.
Re: Double Pendulum in fewer than 100 lines of JavaScript
#7Ain't that a chaotic system which is not deterministic?
Re: Double Pendulum in fewer than 100 lines of JavaScript
#8Ain't that a chaotic system which is not deterministic?
Chaotic systems are deterministic (as shown by a deterministic computer algorithm simulating one). They just aren't predictable except by simulating them (which constrains us by time and accuracy).
Re: Double Pendulum in fewer than 100 lines of JavaScript
#9Would be even better, IMO, with a line in the simulation showing the path traced by each pendulum over time, preferably the arcs drawn could phase through different colours (and possibly decay in visibility). Nice work though.
I did basically this in my first year of college! See [1].
(Note: code was never intended to be visible to the public, and this is old and bad. But hey, it works!)
Re: Double Pendulum in fewer than 100 lines of JavaScript
#10You can get a vigorous chaotic motion going with a high top mass, low bottom mass, and high angles.
That was certainly my goal =)
1. Max Mass 1
2. Min Mass 2
3. Max Phi 1
4. Min Phi 2