[petsc-users] SNES residual and unknown scaling

[anton]

Hi,

Applying -snes_mf_operator to a Stokes problem is quite sensitive to 
scaling of the velocity and pressure unknown (residual) blocks.
Apart from high-level scaling of the entire problem (which we already 
have), it would be also nice to have a sort of low-level scaling 
directly in SNES.
Can someone suggest how it can be best implemented (or probably already 
implemented) in PETSc.

Great thanks,

Anton

P.S. assembled preconditioner matrix with a multigrid solver applied to 
it we already have, because it's also essential for convergence of 
-snes_mf_operator