Double Pendulum Motion: Plotting theta2 vs Time

AI Thread Summary
The discussion focuses on a Python implementation of the Runge-Kutta fourth order method to simulate double pendulum motion. The user is concerned about the accuracy of their plot showing the angle of the second rod (theta2) versus time. They have shared a graph comparing both rod angles over time, seeking insights from others, particularly physicists. A key suggestion is to verify the conservation of total energy in the simulation to assess numerical accuracy. Ensuring energy conservation can help identify potential numerical issues in the model.
thespaceman
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Hello all,
I have written a python code implementing the Runge-Kutta fourth order method for higher orders to approximate the motion of a double pendulum. The problem I am having is that my plot of theta2 (angle of second rod) Vs time looks a little off and I am curious if I have it correct.
Attached is a graph of both rod angles Vs time. The blue is the first rod and the green is the second rod. I figure the opinion of some physicists may be insightful. Thanks :)
-thespaceman
 

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It's not so easy to see just from the plot, whether there are numerical problems or not. A good check is, whether the total energy of the system remains conserved in the numerical simulation.
 

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