Is it sufficient to reset ufl_cell to Cell('interval',1), or will that break other stuff? cheers --cjc ________________________________ From: firedrake-bounces@imperial.ac.uk [firedrake-bounces@imperial.ac.uk] on behalf of Andrew McRae [a.mcrae12@imperial.ac.uk] Sent: 11 November 2014 17:50 To: firedrake Subject: Re: [firedrake] extruded circle mesh problem Overwriting m.coordinates doesn't change m's "ufl_cell", which remains Cell('interval', 2). This gets used during the extrusion process, leaving you with a mesh that thinks it's in 3 dimensions. I'm also not sure why you're using Expression(("0.", "0.")) in the DirichletBC, since 0 will suffice. On 11 November 2014 17:28, Shipton, Jemma <j.shipton@imperial.ac.uk<mailto:j.shipton@imperial.ac.uk>> wrote: Hello, I'm trying to solve a problem that works on an extruded periodic interval mesh on an extruded circle mesh. I am getting the following error: Traceback (most recent call last): File "extruded_circle_helmholtz.py", line 57, in <module> bcs = [DirichletBC(W[0], Expression(("0.", "0.")), "bottom"), File "/home/jemma/src/firedrake/firedrake/bcs.py", line 56, in __init__ self.function_arg = g File "/home/jemma/src/firedrake/firedrake/bcs.py", line 95, in function_arg g = function.Function(self._function_space).interpolate(g) File "/home/jemma/src/firedrake/firedrake/function.py", line 182, in interpolate % (sum(dims), np.prod(expression.value_shape(), dtype=int))) RuntimeError: Expression of length 3 required, got length 2 The problem appears to be that the mesh coordinates have 3 components whereas the extruded interval mesh coordinates only have 2. Any idea how to fix? My code is here: https://gist.github.com/anonymous/dff509883518ef0f5f2d Thanks! Jemma