Set up stokes dg example

test/stokes/CMakeLists.txt

@@ -9,3 +9,8 @@ dune_add_system_test(TARGET stokes_numdiff
                      INIFILE stokes_numdiff.mini
                      SCRIPT dune_vtkcompare.py
                      )
+
+add_generated_executable(UFLFILE stokes_dg.ufl
+                         TARGET stokes_dg_numdiff
+                         FORM_COMPILER_ARGS --numerical-jacobian
+                         )

test/stokes/stokes_dg.ufl

+cell = triangle
+P2 = VectorElement("Lagrange", cell, 2)
+P1 = FiniteElement("Lagrange", cell, 1)
+TH = P2 * P1
+
+v, q = TestFunctions(TH)
+u, p = TrialFunctions(TH)
+
+n = FacetNormal(cell)('+')
+eps = -1.0
+
+r = \
+  + eps*inner(avg(grad(v))*n, jump(u))*dS
+#  + inner(grad(u), grad(v))*dx \
+#  - inner(avg(grad(u))*n, jump(v))*dS \
+
+forms = [r]