Good morning PETSC team, I am currently using a TS object to advance a set of PDEs in time.
However, the computation of the Jacobian is quite expensive and I wish to reuse it across time steps if possible. I am well aware of the options -snes_lag_jacobian and -snes_lag_jacobian_persists, but I do not quite understand how to combine them for what I want. In summary I want to compute the Jacobian only at the beginning of a given time step, reuse that Jacobian for N time steps, and then recompute again at the beginning of the next time step. With my current understanding I have been able to reuse it across time steps by recomputing every N snes iterations, however, this leads to recomputations in the middle of time steps which is not what I desire. Thank you, -Alfredo -- Alfredo Duarte Graduate Research Assistant The University of Texas at Austin
