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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US" style="font-size:11.0pt;font-family:"Courier New"">With DMDA_Q0, I tell him it is cell-centered two-point flux approximation, right?</span><span lang="EN-US"><o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal">Not sure. You specific that you want one variable per cell someplace (not edge or vertex), look at examples and/or documentation.<o:p></o:p></p>
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<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Courier New"">[Buesing, Henrik] I look at KSP example 32. There it says, functions are cell-centered. In the documentation to
<a href="https://www.mcs.anl.gov/petsc/petsc-dev/docs/manualpages/DMDA/DMDASetInterpolationType.html#DMDASetInterpolationType">
DMDASetInterpolationType</a> it just says there exists Q0 and Q1. So, I assume this just means constant and linear interpolation on cuboids.
<o:p></o:p></span></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US">[0]PETSC ERROR: See
</span><a href="http://www.mcs.anl.gov/petsc/documentation/faq.html" target="_blank"><span lang="EN-US">http://www.mcs.anl.gov/petsc/documentation/faq.html</span></a><span lang="EN-US"> for trouble shooting.<br>
</span>[0]PETSC ERROR: Petsc Development GIT revision: v3.8.2-48-g851ec02 GIT Date: 2017-12-05 09:52:17 -0600<br>
[0]PETSC ERROR: /rwthfs/rz/cluster/work/hb111949/EoCoE/aixcelerate17/gge_gnu/bench_run/000023/000000_copy_sub_launch/work/shem_fw64gnu_const.x on a gnu_openmpi named
<a href="http://linuxbmc0008.rz.RWTH-Aachen.DE" target="_blank">linuxbmc0008.rz.RWTH-Aachen.DE</a> by hb111949 Tue Jan 9 16:04:39 2018<br>
[0]PETSC ERROR: Configure options --download-fblaslapack --with-cc=mpicc -with-fc=mpif90 --with-cxx=mpicxx --download-hypre --download-superlu_dist --download-suitesparse --download-scalapack --download-blacs --download-hdf5 --download-parmetis --download-metis
--with-debugging=0 --download-mumps<br>
[0]PETSC ERROR: #1 DMCreateInjection_DA_3D() line 1195 in /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/dm/impls/da/dainterp.c<br>
[0]PETSC ERROR: #2 DMCreateInjection_DA() line 1283 in /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/dm/impls/da/dainterp.c<br>
[0]PETSC ERROR: #3 DMCreateInjection() line 1082 in /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/dm/interface/dm.c<br>
[0]PETSC ERROR: #4 DMCoarsen_DA() line 1219 in /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/dm/impls/da/da.c<br>
[0]PETSC ERROR: #5 DMCoarsen() line 2427 in /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/dm/interface/dm.c<br>
[0]PETSC ERROR: #6 PCSetUp_MG() line 618 in /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/ksp/pc/impls/mg/mg.c<br>
[0]PETSC ERROR: #7 PCSetUp() line 924 in /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/ksp/pc/interface/precon.c<br>
[0]PETSC ERROR: #8 KSPSetUp() line 381 in /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/ksp/ksp/interface/itfunc.c<br>
[0]PETSC ERROR: #9 KSPSolve() line 612 in /rwthfs/rz/cluster/work/hb111949/Code/petsc/src/ksp/ksp/interface/itfunc.c<br>
[0]PETSC ERROR: [1]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------<br>
<br>
<br>
--<br>
Dipl.-Math. <span lang="EN-US">Henrik Büsing<br>
Institute for Applied Geophysics and Geothermal Energy<br>
E.ON Energy Research Center<br>
RWTH Aachen University<br>
------------------------------------------------------<br>
</span><a href="https://maps.google.com/?q=Mathieustr.+10&entry=gmail&source=g"><span lang="EN-US">Mathieustr.
</span>10</a> | Tel <a href="tel:%2B49%20%280%29241%2080%2049907" target="_blank">
+49 (0)241 80 49907</a><br>
52074 Aachen, Germany | Fax <a href="tel:%2B49%20%280%29241%2080%2049889" target="_blank">
+49 (0)241 80 49889</a><br>
------------------------------------------------------<br>
<a href="http://www.eonerc.rwth-aachen.de/GGE" target="_blank">http://www.eonerc.rwth-aachen.de/GGE</a><br>
<a href="mailto:hbuesing@eonerc.rwth-aachen.de" target="_blank">hbuesing@eonerc.rwth-aachen.de</a><br>
------------------------------------------------------<br>
<br>
> -----Ursprüngliche Nachricht-----<br>
> Von: Smith, Barry F. [mailto:<a href="mailto:bsmith@mcs.anl.gov" target="_blank">bsmith@mcs.anl.gov</a>]<br>
> Gesendet: 09 January 2018 15:10<br>
> An: Buesing, Henrik <<a href="mailto:hbuesing@eonerc.rwth-aachen.de" target="_blank">hbuesing@eonerc.rwth-aachen.de</a>><br>
> Cc: petsc-users <<a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a>><br>
> Betreff: Re: [petsc-users] Geometric multigrid with a cell-centered<br>
> discretization<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:12.0pt">><br>
><br>
> With cell centered elements each element is sliced in half in each of<br>
> the three directions for refinement (or you can refine only in 1 or 2 of<br>
> the dimensions if you like). This means that the ratio of mx to MX needs<br>
> to be 2 (or 4).So your numbers are fine.<br>
><br>
> > On Jan 9, 2018, at 7:59 AM, Buesing, Henrik <<a href="mailto:hbuesing@eonerc.rwth-%0b" target="_blank">hbuesing@eonerc.rwth-<br>
</a>> <a href="http://aachen.de" target="_blank">aachen.de</a>> wrote:<br>
> ><br>
> > Dear all,<br>
> ><br>
> > I am using DMDACreate3d to generate my domain and a cell-centered<br>
> > two-point flux approximation as discretization. I use geometric<br>
> > Multigrid (-pc_type mg) with DMDASetInterpolationType(petsc_da,<br>
> > DMDA_Q0, petsc_ierr). With DM_BOUNDARY_GHOSTED as boundary type in<br>
> > DMDACreate3d, I get<br>
> ><br>
> > [0]PETSC ERROR: Arguments are incompatible [0]PETSC ERROR: Ratio<br>
> > between levels: (mx - 1)/(Mx - 1) must be integer: mx 1536 Mx 768<br>
><br>
> We need ALL the output from the error (always). It should never be<br>
> doing this check in your case so something is wrong with the order of<br>
> your code perhaps.<br>
><br>
> Barry<br>
><br>
> ><br>
> > With DM_BOUNDARY_PERIODIC, I get invalid accesses when I assemble the<br>
> matrix.<br>
> ><br>
> > Can I somehow tell him, that I have a cell-centered grid, or do I have<br>
> to resort to using N+1 in my dimensions?<br>
> ><br>
> > Thank you!<br>
> > Henrik<br>
> ><br>
> ><br>
> > --<br>
> > Dipl.-Math. Henrik Büsing<br>
> > Institute for Applied Geophysics and Geothermal Energy E.ON Energy<br>
> > Research Center RWTH Aachen University<br>
> > ------------------------------------------------------<br>
> > <a href="https://maps.google.com/?q=Mathieustr.+10&entry=gmail&source=g">Mathieustr. 10</a> | Tel
<a href="tel:+49%20241%208049907" target="_blank">+49 (0)241 80 49907</a><br>
> > 52074 Aachen, Germany | Fax <a href="tel:+49%20241%208049889" target="_blank">
+49 (0)241 80 49889</a><br>
> > ------------------------------------------------------<br>
> > <a href="http://www.eonerc.rwth-aachen.de/GGE" target="_blank">http://www.eonerc.rwth-aachen.de/GGE</a><br>
> > <a href="mailto:hbuesing@eonerc.rwth-aachen.de" target="_blank">hbuesing@eonerc.rwth-aachen.de</a><br>
> > ------------------------------------------------------<o:p></o:p></p>
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