DG work

Author: connorjward

demo.py check_simple.pydemo.py renamed to check_simple.py

@@ -1,19 +1,7 @@
 from firedrake import *
 
 
-# plex = PETSc.DMPlex().createBoxMesh(
-#     (2, 2, 2),
-#     lower=(0, 0, 0),
-#     upper=(1, 1, 1),
-#     simplex=False,
-#     periodic=True,
-#     interpolate=True,
-#     sparseLocalize=False,
-# )
-# mesh = Mesh(plex)
-
 mesh = UnitSquareMesh(2, 2)
-V = FunctionSpace(mesh, "DG", 1)
 x, _ = SpatialCoordinate(mesh)
 
 assert np.allclose(assemble(1 * dx(domain=mesh)), 1)

firedrake/cython/dmcommon.pyx

@@ -3930,29 +3930,31 @@ def set_coordinate_section_and_such(mesh, coordinates):
     plex = mesh.topology_dm
     coordinate_element = coordinates.ufl_element()
     gdim = plex.getCoordinateDim()
+
+    # the existing section has the correct numbering but is scalar, expand to gdim
+    scalar_dm = coordinates.function_space().dm
+    scalar_section = scalar_dm.getLocalSection()
+    p_start, p_end = scalar_section.getChart()
+
+    vector_section = PETSc.Section().create(comm=scalar_section.comm)
+    vector_section.setNumFields(1)
+    vector_section.setFieldComponents(0, gdim)
+    vector_section.setChart(p_start, p_end)
+    vector_section.setPermutation(scalar_section.getPermutation())
+
+    for p in range(p_start, p_end):
+        scalar_ndof = scalar_section.getDof(p)
+        CHKERR(PetscSectionSetDof(vector_section.sec, p, scalar_ndof*gdim))
+        CHKERR(PetscSectionSetFieldDof(vector_section.sec, p, 0, scalar_ndof*gdim))
+    vector_section.setUp()
+
     if coordinate_element.family() == "Lagrange":
-        # the existing section has the correct numbering but is scalar, expand to gdim
-        scalar_dm = coordinates.function_space().dm
-        scalar_section = scalar_dm.getLocalSection()
-        p_start, p_end = scalar_section.getChart()
-
-        vector_section = PETSc.Section().create(comm=scalar_section.comm)
-        vector_section.setNumFields(1)
-        vector_section.setFieldComponents(0, gdim)
-        vector_section.setChart(p_start, p_end)
-        vector_section.setPermutation(scalar_section.getPermutation())
-
-        for p in range(p_start, p_end):
-            scalar_ndof = scalar_section.getDof(p)
-            CHKERR(PetscSectionSetDof(vector_section.sec, p, scalar_ndof*gdim))
-            CHKERR(PetscSectionSetFieldDof(vector_section.sec, p, 0, scalar_ndof*gdim))
-        vector_section.setUp()
-
-        # set coordinates
         # apparently gdim ignored in this call and set explicitly below
         CHKERR(DMSetCoordinateSection(plex.dm, gdim, vector_section.sec))
         plex.setCoordinateDim(gdim)
-
         plex.setCoordinatesLocal(coordinates.dat._vec)
     else:
-        raise NotImplementedError("Need to do DG")
+        plex.setCellCoordinateDM(plex.getCoordinateDM().clone())
+        plex.setCellCoordinateSection(gdim, vector_section)  # gdim ignored
+        plex.setCoordinateDim(gdim)
+        plex.setCellCoordinatesLocal(coordinates.dat._vec)

firedrake/mesh.py

@@ -2309,6 +2309,13 @@ def callback(self):
             # Finish the initialisation of mesh topology
             self.topology.init()
             coordinates_fs = functionspace.FunctionSpace(self.topology, self.ufl_coordinate_element())
+
+            # reordered_coords only needs to reorder the coordinates
+            # *some of the time*. If the input is a DM that has already
+            # been reordered to respect Firedrake then we don't have to do
+            # anything. Otherwise, we have the set the correct section.
+            # TODO: Ask Matt if there is a nice way to do this.
+
             coordinates_data = dmcommon.reordered_coords(topology.topology_dm, coordinates_fs.dm.getDefaultSection(),
                                                          (self.num_vertices(), self.geometric_dimension()))
             coordinates = function.CoordinatelessFunction(coordinates_fs,