Yes, this is exactly what I was looking for. Thank you all. On Mon, Aug 29, 2022 at 8:02 AM Matthew Knepley <[email protected]> wrote:
> On Sun, Aug 28, 2022 at 12:44 PM Nicholas Arnold-Medabalimi < > [email protected]> wrote: > >> Hi >> >> I'm working on a finite volume implementation using DMPlex. I was >> wondering what the best-considered way to add cell variables to the DM that >> we don't want to be part of the ksp/snes solve. As far as I can tell, if I >> add an extra section with those, they will still be part of the F and U >> vectors in the solver callbacks (to be expected). But my impression is that >> that will just inflate the system size even if they have an F=0? Or is the >> solver able to notice variables that are not dependent for the solve. >> >> Alternatively, I have been just making a separate DM with those but that >> feels a bit clunky especially if any mesh refinement occurs. >> > > Mark is correct. We have been using a two DM strategy. You can attach this > auxiliary data using > > https://petsc.org/main/docs/manualpages/DM/DMSetAuxiliaryVec/ > > The idea is that you define a layout for your extra information using a > new DM, then create a Vec for it, and attach it to the DM. This > can be pulled out by any callback function, and the DM can be pulled out > of the vector. In the Plex pointwise functions for residual > and Jacobian, auxiliary data is automatically interpolated to the > quadrature points as well. > > Is this what you were looking for? > > Thanks, > > Matt > > >> Any advice would be much appreciated. >> >> Thanks >> Nicholas >> >> -- >> Nicholas Arnold-Medabalimi >> >> Ph.D. Candidate >> Computational Aeroscience Lab >> University of Michigan >> > > > -- > What most experimenters take for granted before they begin their > experiments is infinitely more interesting than any results to which their > experiments lead. > -- Norbert Wiener > > https://www.cse.buffalo.edu/~knepley/ > <http://www.cse.buffalo.edu/~knepley/> > -- Nicholas Arnold-Medabalimi Ph.D. Candidate Computational Aeroscience Lab University of Michigan
