>From your output, it seems a triangle cell. Reading the documentation of DMPlexGetTransitiveClosure I have already pointed you to: the output is interleaved between points (cell, edges and vertices in this case) and their relative orientation wrt the point of higher dimension.
Reading your output 0 0 -> cell number 0 (relative orientation is 0) then the edges (all edges are points locally numbered from eStart to eEnd, where DMPlexGetDepthStratum(dm,1,&eStart,&eEnd)) 370 -2 369 -2 368 -2 -> cell 0 is made up by points 370, 369 and 368 (traversed in this specific order), and each edge must be traversed -2 (from second endpoint to first) then the vertices (start and end of local per process numbering via DMPlexGetDepthStratum(dm,0,&vStart,&vEnd)) 309 0 306 0 312 0 -> vertices have no orientation. Il giorno lun 22 feb 2021 alle ore 15:09 Fabien Vergnet < [email protected]> ha scritto: > Hi Stefano, > > Thank you for your response. > > Could you explain more what the output of DMPlexGetTransitiveClosure is ? > For example for cell 0 I get the following array of size 14 for the closure: > > 0 0 370 -2 369 -2 368 -2 309 0 306 0 312 0 > > but I do not understand the order of the points (center of the cell, > middle of the edges, vertices ?). Also what the orientation means for each > point ? > > Regards, > Fabien > > Le 22 févr. 2021 à 12:48, Stefano Zampini <[email protected]> a > écrit : > > The plex way is to use the transitive closure > https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/DMPLEX/DMPlexGetTransitiveClosure.html > and filter out points you are not interested in. > See for example > https://gitlab.com/petsc/petsc/-/blob/master/src/dm/impls/plex/plex.c#L828 > and > https://gitlab.com/petsc/petsc/-/blob/master/src/dm/impls/plex/plex.c#L833 > > Il giorno lun 22 feb 2021 alle ore 14:28 Fabien Vergnet < > [email protected]> ha scritto: > >> Dear PETSc community, >> >> Thank you for your amazing work. I discovered PETSc recently and I need >> your help for a project. >> >> As a training, I would like to assemble the Finite Element Matrix for the >> Poisson problem on a part of my mesh. So, I create a DMPlex from a .msh >> file and I create a Submesh with >> >> DMPlexCreateSubmesh(dm, label, 1, PETSC_TRUE, &subdm); >> >> In order to assemble my Finite Element Matrix, I need to iterate over the >> cells of the mesh (which are triangles) and identify the vertices >> composing each cell. >> >> My question is the following : how can I get, for each cell, the vertices >> composing the cell ? >> >> I have tried to uninterpolate the subdm with DMPlexUninterpolate (with >> the objective to get the vertices from DMPlexGetCone) but it does not >> seem to work for a Submesh since I get the following error: >> >> ---------- >> >> [0]PETSC ERROR: --------------------- Error Message >> -------------------------------------------------------------- >> [0]PETSC ERROR: Invalid argument >> [0]PETSC ERROR: Not for partially interpolated meshes >> [0]PETSC ERROR: See https://www.mcs.anl.gov/petsc/documentation/faq.html for >> trouble shooting. >> [0]PETSC ERROR: Petsc Release Version 3.14.4, Feb 03, 2021 >> [0]PETSC ERROR: Configure options >> --prefix=/users/home/vergnet/apps/spack/opt/spack/linux-ubuntu20.04-zen2/gcc-9.3.0/petsc-3.14.4-xtae5tcwlzkb4oiifbayj77bqlz5nngk >> --with-ssl=0 --download-c2html=0 --download-sowing=0 --download-hwloc=0 >> CFLAGS= FFLAGS= CXXFLAGS= >> --with-cc=/users/home/vergnet/apps/spack/opt/spack/linux-ubuntu20.04-zen2/gcc-9.3.0/openmpi-4.0.5-ygn7zymoy7crl7b4xsdkc4zmfojugmdy/bin/mpicc >> --with-cxx=/users/home/vergnet/apps/spack/opt/spack/linux-ubuntu20.04-zen2/gcc-9.3.0/openmpi-4.0.5-ygn7zymoy7crl7b4xsdkc4zmfojugmdy/bin/mpic++ >> --with-fc=/users/home/vergnet/apps/spack/opt/spack/linux-ubuntu20.04-zen2/gcc-9.3.0/openmpi-4.0.5-ygn7zymoy7crl7b4xsdkc4zmfojugmdy/bin/mpif90 >> --with-precision=double --with-scalar-type=real --with-shared-libraries=1 >> --with-debugging=0 --with-64-bit-indices=0 COPTFLAGS= FOPTFLAGS= >> CXXOPTFLAGS= >> --with-blaslapack-lib=/users/home/vergnet/apps/spack/opt/spack/linux-ubuntu20.04-zen2/gcc-9.3.0/openblas-0.3.13-6b3u6zc5j4hvauqh3ldcwnf7lm2o4vyl/lib/libopenblas.so >> --with-x=0 --with-clanguage=C --with-scalapack=0 --with-cuda=0 >> --with-metis=1 >> --with-metis-dir=/users/home/vergnet/apps/spack/opt/spack/linux-ubuntu20.04-zen2/gcc-9.3.0/metis-5.1.0-lm3k7dh2vslghqtqc6dvcpnc54bfpqq2 >> --with-hypre=1 >> --with-hypre-dir=/users/home/vergnet/apps/spack/opt/spack/linux-ubuntu20.04-zen2/gcc-9.3.0/hypre-2.20.0-4pyxhku65wb5lmh2fpflhmjmow2pbjg7 >> --with-parmetis=1 >> --with-parmetis-dir=/users/home/vergnet/apps/spack/opt/spack/linux-ubuntu20.04-zen2/gcc-9.3.0/parmetis-4.0.3-pfiam4ccxkyqpapejcdjtlyr6cyz7irc >> --with-mumps=0 --with-trilinos=0 --with-fftw=0 --with-valgrind=0 >> --with-gmp=0 --with-libpng=0 --with-giflib=0 --with-mpfr=0 --with-netcdf=0 >> --with-pnetcdf=0 --with-moab=0 --with-random123=0 --with-exodusii=0 >> --with-cgns=0 --with-memkind=0 --with-p4est=0 --with-saws=0 --with-yaml=0 >> --with-libjpeg=0 --with-cxx-dialect=C++11 >> --with-superlu_dist-include=/users/home/vergnet/apps/spack/opt/spack/linux-ubuntu20.04-zen2/gcc-9.3.0/superlu-dist-6.4.0-bagymefhq7s7gerf7jxwiv4fv7szoljh/include >> --with-superlu_dist-lib=/users/home/vergnet/apps/spack/opt/spack/linux-ubuntu20.04-zen2/gcc-9.3.0/superlu-dist-6.4.0-bagymefhq7s7gerf7jxwiv4fv7szoljh/lib/libsuperlu_dist.a >> --with-superlu_dist=1 --with-suitesparse=0 --with-ptscotch=0 >> --with-hdf5-include=/users/home/vergnet/apps/spack/opt/spack/linux-ubuntu20.04-zen2/gcc-9.3.0/hdf5-1.10.7-dkfs4ir3hlahyfs5z4xcmsf4ogklimji/include >> --with-hdf5-lib=/users/home/vergnet/apps/spack/opt/spack/linux-ubuntu20.04-zen2/gcc-9.3.0/hdf5-1.10.7-dkfs4ir3hlahyfs5z4xcmsf4ogklimji/lib/libhdf5.so >> --with-hdf5=1 >> --with-zlib-include=/users/home/vergnet/apps/spack/opt/spack/linux-ubuntu20.04-zen2/gcc-9.3.0/zlib-1.2.11-2pwsgfxppopolmjj6tf34k5jsaqzpodo/include >> --with-zlib-lib=/users/home/vergnet/apps/spack/opt/spack/linux-ubuntu20.04-zen2/gcc-9.3.0/zlib-1.2.11-2pwsgfxppopolmjj6tf34k5jsaqzpodo/lib/libz.so >> --with-zlib=1 >> [0]PETSC ERROR: #1 DMPlexUninterpolate() line 1514 in >> /tmp/vergnet/spack-stage/spack-stage-petsc-3.14.4-xtae5tcwlzkb4oiifbayj77bqlz5nngk/spack-src/src/dm/impls/plex/plexinterpolate.c >> [0]PETSC ERROR: #2 assemble_mass() line 59 in >> /users/home/vergnet/codes/cilia/cilia/cpp/assembling.hpp >> >> ---------- >> >> Attached are a minimal working example, a mesh file and a makefile. >> >> Any ideas or suggestions are more than welcome ! >> >> Regards, >> Fabien >> >> >> >> > > -- > Stefano > > > -- Stefano
