Dear Firedrakers, on an extruded mesh: meshbase = RectangleMesh(Nx, Ny, Lx, Ly, quadrilateral=True) mesh = ExtrudedMesh(meshbase, Nz, Delta_z) horiz_elt = FiniteElement("DG", quadrilateral, 0) vert_elt = FiniteElement("DG", interval, 0) elt = OuterProductElement(horiz_elt, vert_elt) How can I access the element center and the center of the element faces? Thank you! Henrik -- Dipl.-Math. Henrik Büsing Applied Geophysics and Geothermal Energy E.ON Energy Research Center RWTH Aachen University ----------------------------------------------- Mathieustr. 10 | Tel +49 (0)241 80 49907 52074 Aachen, Germany | Fax +49 (0)241 80 49889 ----------------------------------------------- http://www.eonerc.rwth-aachen.de/GGE hbuesing@eonerc.rwth-aachen.de -----------------------------------------------