Hello, Thank you the various options.
Use case here would be obtaining the exact output generated by option 1), DMView() with PETSC_VIEWER_HDF5_VIZ; in particular, the matrix generated under /viz/topology/cells. > There are several ways you might do this. It helps to know what you are > aiming for. > > 1) If you just want this output, it might be easier to just DMView() with the > PETSC_VIEWER_HDF5_VIZ format, since that just outputs the cell-vertex > topology and coordinates Is it possible to get this information in memory, onto a Mat, Vec or some other Int array object directly? it would be handy to have it in order to manipulate it and/or save it to a different format/file. Saving to an HDF5 and loading it again seems redundant. > 2) You can call DMPlexUninterpolate() to produce a mesh with just cells and > vertices, and output it in any format. > > 3) If you want it in memory, but still with global indices (I don't > understand this use case), then you can use DMPlexCreatePointNumbering() for > an overall global numbering, or DMPlexCreateCellNumbering() and > DMPlexCreateVertexNumbering() for separate global numberings. Perhaps I missed it, but getting the connectivity matrix in /viz/topology/cells/ did not seem directly trivial to me from the list of global indices returned by DMPlexGetCell/Point/VertexNumbering() (i.e. I assume all the operations done when calling DMView()). Thanks, Noam.
