> On 27 Feb 2023, at 3:59 PM, Matthew Knepley <knep...@gmail.com> wrote: > > On Mon, Feb 27, 2023 at 9:53 AM Zongze Yang <yangzon...@gmail.com > <mailto:yangzon...@gmail.com>> wrote: >> Hi, Matt, >> >> I tested coarsening a mesh by using ParMMg without firedrake, and found some >> issues: >> see the code and results here: https://gitlab.com/petsc/petsc/-/issues/1331 >> >> Could you have a look and give some comments or suggestions? > > I replied on the issue. More generally, the adaptive refinement software has > not seen wide use
:) Matt probably meant “the _DMPlex interface_ to adaptive refinement software has not seen wide use”, Mmg has been rather widely used for 10+ years (here is a 13-year old presentation https://www.ljll.math.upmc.fr/hecht/ftp/ff++days/2010/exposes/Morice-MeshMetric.pdf). Thanks, Pierre > , and I expect > more of these kinds of bugs until more people use it. > > Thanks, > > Matt > >> Best wishes, >> Zongze >> >> >> On Mon, 27 Feb 2023 at 20:19, Matthew Knepley <knep...@gmail.com >> <mailto:knep...@gmail.com>> wrote: >>> On Sat, Feb 18, 2023 at 6:41 AM Zongze Yang <yangzon...@gmail.com >>> <mailto:yangzon...@gmail.com>> wrote: >>>> Another question on mesh coarsening is about `DMCoarsen` which will fail >>>> when running in parallel. >>>> >>>> I generate a mesh in Firedrake, and then create function space and >>>> functions, after that, I get the dmplex and coarsen it. >>>> When running in serials, I get the mesh coarsened correctly. But it failed >>>> with errors in ParMMG when running parallel. >>>> >>>> However, If I did not create function space and functions on the original >>>> mesh, everything works fine too. >>>> >>>> The code and the error logs are attached. >>> >>> I believe the problem is that Firedrake and PETSc currently have >>> incompatible coordinate spaces. We are working >>> to fix this, and I expect it to work by this summer. >>> >>> Thanks, >>> >>> Matt >>> >>>> Thank you for your time and attention。 >>>> >>>> Best wishes, >>>> Zongze >>>> >>>> >>>> On Sat, 18 Feb 2023 at 15:24, Zongze Yang <yangzon...@gmail.com >>>> <mailto:yangzon...@gmail.com>> wrote: >>>>> Dear PETSc Group, >>>>> >>>>> I am writing to inquire about the function DMAdaptLabel in PETSc. >>>>> I am trying to use it coarse a mesh, but the resulting mesh is refined. >>>>> >>>>> In the following code, all of the `adpat` label values were set to 2 >>>>> (DM_ADAPT_COARSEN). >>>>> There must be something wrong. Could you give some suggestions? >>>>> >>>>> ```python >>>>> from firedrake import * >>>>> from firedrake.petsc import PETSc >>>>> >>>>> def mark_all_cells(mesh): >>>>> plex = mesh.topology_dm >>>>> with PETSc.Log.Event("ADD_ADAPT_LABEL"): >>>>> plex.createLabel('adapt') >>>>> cs, ce = plex.getHeightStratum(0) >>>>> for i in range(cs, ce): >>>>> plex.setLabelValue('adapt', i, 2) >>>>> >>>>> return plex >>>>> >>>>> mesh = RectangleMesh(10, 10, 1, 1) >>>>> >>>>> x = SpatialCoordinate(mesh) >>>>> V = FunctionSpace(mesh, 'CG', 1) >>>>> f = Function(V).interpolate(10 + 10*sin(x[0])) >>>>> triplot(mesh) >>>>> >>>>> plex = mark_all_cells(mesh) >>>>> new_plex = plex.adaptLabel('adapt') >>>>> mesh = Mesh(new_plex) >>>>> triplot(mesh) >>>>> ``` >>>>> >>>>> Thank you very much for your time. >>>>> >>>>> Best wishes, >>>>> Zongze >>> >>> >>> -- >>> 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/> > > > -- > 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/>
