Peter, THey are equivalent other than one may provide a simpler set of direction cosine matrices and angular velocity definitions. The "Body" method should give simpler equations of motion in the end because we try to use pre-simplified forms of the equations. I don't know why you'd see faster with the intermediate frame method.
You can use sympy's count_ops() function to see how many operations each symbolic form gives. The one with more operations should ultimately be slower when lambdified(). Jason moorepants.info +01 530-601-9791 On Tue, Jun 29, 2021 at 5:09 AM Peter Stahlecker <[email protected]> wrote: > When I want to do this, it seems to me there are these possibilities: > > 1. > A = N.orientnew(‚A‘, ‚Body‘, [q1, q2, q3], ‚123‘) > This does it in one step > > 2. > I use two intermediate frames and use the word ‚Axis‘ instead of ‚Body‘ > > Geometrically, this should be the same, but it seems to me, that with the > intermediate frames establishing Kane‘s equations, lambdifying them and > doing the numerical integration is MUCH faster. > > Are methods 1 and 2 not equivalent, as I assumed, or am I doing something > wrong? > > Thanks for any explanation! > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/d1597154-f8a8-42fa-b29b-6e8f57062441n%40googlegroups.com > <https://groups.google.com/d/msgid/sympy/d1597154-f8a8-42fa-b29b-6e8f57062441n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAP7f1AhvTHkfn8_Wc7L9i7em3QvDHn6MPBHoWwqvK9qOUw3QfA%40mail.gmail.com.
