Support for H1 BrokenElement in FunctionSpace
I have a question for the developers.
I'm interested in storing elemental matrices in the form a large sparse block-diagonal matrix.
To this aim, I have tried using the BrokenElement class.
My question is: Is there a mathematical/implementation reason because of which a FunctionSpace with BrokenElement can not be constructed?
Consider the following code:
import dolfin as dl mesh = dl.UnitSquareMesh(1,1) elH1 = dl.FiniteElement("Lagrange", mesh.ufl_cell(), 1) elH1_b = dl.BrokenElement(elH1) Vh = dl.FunctionSpace(mesh, elH1_b)
The code gives a segmentation fault with error:
Calling FFC just-in-time (JIT) compiler, this may take some time. Cannot handle this element type: BrokenElement(<CG1 on a triangle>)
Which FEniCS package is raising the error? Is there a walk-around?
An alternative could be using DG. However, do the DG spaces differ from their corresponding CG version only at the DofMap level or also in term of shape functions?
Thanks in advance!