On Fri, Sep 23, 2016 at 9:38 AM, 丁老师 <[email protected]> wrote:
> Dear friends: > In the projection method for the solution of incompressible flow, a > pressure equation with four neuman bcs need to be solved. > but the pressure matrix is singular. it gives divergence solution. how to > solve this kind of equations. > Tell the matrix it has a nullspace of constants: http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Mat/MatSetNullSpace.html Thanks, Matt > Regards > > > > > > > > > > > > > > > > > > > > > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener
