Any better choice if I can do right precondition?
Merge Jacobian to Function evaluation has performance lost.
On 2023/10/4 02:13, Barry Smith wrote:
Simply evaluate the Jacobian during your SNESComputeFunction and
save it for SNESComputeJacobian.
On Oct 3, 2023, at 1:51 PM, Gong Ding <gongd...@cn.cogenda.com> wrote:
Hi all,
I'd like to do a special jacobian precondition during the snes
iteration, for which jacobian matrix and RHS vector must be modified
explicitly.
In the SNESComputeJacobian, the preconditioner P is built after
assembly of jacobian matrix.
I need to multiply P to J and RHS vector explicitly as left
precondition before the solve stage of J*dx = rhs.
However, I find that petsc evaluates function before jacobian, so P*RHS vector
can not be processed at SNESComputeFunction.
As a result, I must find a hook function after SNESComputeJacobian and before
the solve stage.
Any suggest?
Gong Ding
