Hello! I'm trying to adapt a serial Finite Element code using PETSc. In this code it reads in special stiffness terms between the boundary DoFs from an input file, and add them to corresponding locations in the global Jacobian matrix. I currently use a DM Plex object to store the mesh information. My understanding is that once the DM is distributed its points are renumbered across different ranks. I wonder if there is a good way to find the corresponding entries that needs to be modified in the global Jacobian matrix? For Vectors I'm currently creating a Natural Vector and simply do DMPlexNaturalToGlobal. Is there a way to create a "Natural Mat" just like "Natural Vector" and then do some sort of NaturalToGlobal for this Mat? Any help would be highly appreciated! Kevin