I am trying to learn the DifferentiableSystem to solve a system of equations of (v1,v2)
v1_t + f(v1) + g(v2) = 0
h(v2) = 0
Here, equation (1) has a time derivative of v1. and (2) doesn't have any time derivatives.
I am wondering what I should write to the functions element_time_derivative and the element_constraint in FEMSystem class.
How fast the DifferentiableSystem method can compare to the NonlinearImplicitSystem class + jacobian & residual functions.
Thank you very much for your help,
/ Ming Q.