[petsc-dev] question about time integrators, TS

[Mark Adams]

We have a question about the RHS Jacobian (G) for TS.  The manual says:

• Jacobian Gu
If using a fully implicit method and the function G() is provided, one
also can provide an appropriate (approximate) Jacobian matrix of G().

If we use, say, backward Euler and provide a G Jacobian, does PETSc
use this G Jacobian in some way? or is the G Jacobian only used for
IMEX methods?

Mark