Doubts about SNESMF and matrix-free preconditioners

Rafael Santos Coelho rafaelsantoscoelho at
Tue Nov 18 13:22:13 CST 2008

Originally, my idea is to implement this
As far as I`m concerned, there`s no need to form and store any matrices,
only the diagonal elements of the jacobian like I said. This way, I believe
I`d have to stick with option #2.

With regard to "The matrix it will receive will be the MFFD that is created
by -mat_mf.", what matrix is that actually? The one that is created by the
`MatCreateMFFD` routine?

"Then you would have to extract the KSP and set your matrix-free PC there."

Do the calls to PCSetType and PCShellSetApply plus my own implementation of
the `MatrixFreePreconditioner` function do that?

Best regards,

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <>

More information about the petsc-users mailing list