[petsc-users] DMMG preconditioner used in KSP

[Shao-Ching Huang]

Hi

I can trying to solve a linear system

(A+B)x=b

where A is the standard finite difference Laplacian matrix and B has
only a few elements (i.e. B's number of non-zero entries is much much
smaller than A's).
Is it possible to precondition by applying DMMG on A (like in ex34.c)
in a KSP solver? Is there an example that I can follow to set this up?

Thanks,

Shao-Ching