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Shashwat Tiwari <shaswat121...@gmail.com> writes: > Yeah I have use that too. I am getting zero values even in the Local Vector. Corresponding to the ghost cells you created for that purpose, or otherwise? > On Sat, 13 Jun 2020, 12:57 am , <j...@jedbrown.org> wrote: > >> You need DMGlobalToLocal. >> >> VecGhost is a different thing. >> >> On Jun 12, 2020 13:17, Shashwat Tiwari <shaswat121...@gmail.com> wrote: >> >> Hi, >> I am writing a first order 2D solver for unstructured grids with periodic >> boundaries using DMPlex. After generating the mesh, I use >> "DMSetPeriodicity" function to set periodicity in both directions. After >> which I partition the mesh (DMPlexDistribute), construct ghost cells >> (DMPlexConstructGhostCells), create a section, and set some initial values >> in the global vector. Then I use "VecGhostUpdateBegin" to start updating >> the boundary ghost cell values, but, I get the following error in case I >> use multiple processors: >> >> [0]PETSC ERROR: Invalid argument >> [0]PETSC ERROR: Vector is not ghosted >> [0]PETSC ERROR: See https://www.mcs.anl.gov/petsc/documentation/faq.html >> for trouble shooting. >> >> if I run with a single process, there is no error but the values remain >> empty (zero) and are not updated. Kindly let me know, if I am missing some >> crucial step before I can update the ghost values in order to implement the >> periodic bc, or if there is any other approach to achieve it. I am >> attaching a small code to demonstrate the issue for your reference. >> >> Regards, >> Shashwat >> >> >>
