[petsc-users] TS without an RHSJacobian

[Gideon Simpson]

What happens if I use TS for a nonlinear problem without specifying the 
RHSJacobian?  There’s some mention in the manual that if you’re working with a 
problem built on a da, it will use finite differences to approximate it, but I 
found the language a bit ambiguous.  Could someone elaborate? 
-gideon