[petsc-users] Geometric multigrid with a cell-centered discretization

[Buesing, Henrik]

Dear all,

I am using DMDACreate3d to generate my domain and a cell-centered two-point flux approximation as discretization. I use geometric Multigrid (-pc_type mg) with DMDASetInterpolationType(petsc_da, DMDA_Q0, petsc_ierr). With DM_BOUNDARY_GHOSTED as boundary type in DMDACreate3d, I get

[0]PETSC ERROR: Arguments are incompatible
[0]PETSC ERROR: Ratio between levels: (mx - 1)/(Mx - 1) must be integer: mx 1536 Mx 768

With DM_BOUNDARY_PERIODIC, I get invalid accesses when I assemble the matrix.

Can I somehow tell him, that I have a cell-centered grid, or do I have to resort to using N+1 in my dimensions?

Thank you!
Henrik


--
Dipl.-Math. Henrik Büsing
Institute for Applied Geophysics and Geothermal Energy
E.ON Energy Research Center
RWTH Aachen University
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hbuesing at eonerc.rwth-aachen.de
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