[petsc-users] submatrix times subvector

[Tabrez Ali]

Hello

I am solving a system of equations of the form:

|A C| |u1| = |f1|
|C'B| |u2|   |f2|

After each solve, I need to perform B*f2 before updating f. Should I use 
MatGetSubMatrix/VecGetSubVector followed by MatMult or is there 
something simpler.

Thanks in advance.

T

-- 
No one trusts a model except the one who wrote it; Everyone trusts an observation except the one who made it- Harlow Shapley