Very nice illustration. I am curious however to why the pendulum starts to move when initializing it at it's upward equilibrium
(phi1 = pi;dtphi1 = 0;phi2 = pi;dtphi2 = 0;)
Is this due to approximation mistakes by matlab where the number pi is represented with a finite number of decimals?
Results are very inconsistent with other projects and online simulators, but they seem to use iterative calculations and not ivp deq's. Also equations in m-file are inconsistent with pdf documentation. Can you please elaborate on that?