I feel the model is not correct - help please!
Pendulum-2-animation.sm (22.59 KiB) downloaded 70 time(s).

Hi Valery. The system is coupled. This is a way to solve it.



double_pendulum_lagrangian.sm (122.44 KiB) downloaded 60 time(s).
double_pendulum_lagrangian.pdf (637.78 KiB) downloaded 31 time(s).

Best regards.
Alvaro.

Yes, that is correct; I previously reported on the limitations regarding the systems.

The algorithm does not currently classify the task, so issues may arise with complex problems that the current method cannot solve. It might produce a plausible-looking solution that does not actually address the problem at hand.

Thanks, Alvaro.
It reminds me of an old joke.
A funeral. A passerby asks, "Who are they burying?"
"That guy lying in the coffin."
That was a mathematician's answer—completely accurate and completely useless.

Mathcad 15

If mathematics is a tautology, then life must be one too. That joke reminds me of the one a plant process engineer played on me when I went to get the bourdon gauge I was supposed to install. Without a word, he handed me a brown box. That was when I have the bad idea of asking what was inside. His answer was that it contained a mechanical device that measures fluid pressure using a curved, flattened metal tube that straightens as internal pressure increases, driving an indicator needle across a calibrated dial.

The RKA function includes the necessary procedures to solve hard coupled systems.



double_pendulum_RKA.pdf (483.53 KiB) downloaded 25 time(s).
double_pendulum_RKA.sm (43.57 KiB) downloaded 54 time(s).

Best regards.
Alvaro.