Open SeanMatthewNolan opened 6 years ago
Continuing my thought from when I closed #83. To implement BDF methods I think there'd be two main steps in your journey.
TimeStepper()
subclass similar to how I have the RK()
time stepper subclassed but it raises a NotImplementedError
when you try to solve an implicit problem with it.
I have been reading online about solving DAE problems. It appears that BDF (Backward differentiation formula) implicit methods are able to be able to handle the incorporation of algebraic equations in an efficient way. It may still result in slowing the solver to much, but in my opinion, it is worth checking out to enable solving some problems where both explicit solving and index reduction fail. Collocation may be used to bypass the requirement also.