Hello, When I define a rectanglemesh, as say the following, mesh = RectangleMesh(n0, n0, Lx, Ly, reorder = None) I know that I can impose zero Dirichlet boundary conditions using bc = DirichletBC(Vcg, 0.0, "on_boundary") However, if I impose a mesh created by gmsh (the circle I asked about last week) say using mesh = Mesh("circle.msh") I get the right geometry but it doesn't impose the zero boundary conditions. Is there something you need to do to impose these boundary conditions? Cheers, Francis ------------------ Francis Poulin Associate Professor Department of Applied Mathematics University of Waterloo email: fpoulin@uwaterloo.ca Web: https://uwaterloo.ca/poulin-research-group/ Telephone: +1 519 888 4567 x32637