[firedrake] Problem with paraview and vector functions

[luca.mechelli at uni-konstanz.de]

Dear all,

I encountered a problem when visualizing a function of a vector function space in paraview, if the order of the finite element is higher than 1. For example, if I run the following code, paraview shows the error message: "Cell type UnknownClass(69) is not a 3D cell. Missing original point id arrays. "


mesh = UnitSquareMesh(10, 10)
V = VectorFunctionSpace(mesh, "CG", 2)
v = Function(V)
outfile = File("test.pvd")
outfile.write(v)


If I replace the instruction "V = VectorFunctionSpace(mesh, "CG", 2)" with "V = VectorFunctionSpace(mesh, "CG", 1)", then I can visualize correctly the function in paraview. Could you please explain me which is my mistake?

As temporary solution I have defined an additional space V_2 = VectorFunctionSpace(mesh, "CG", 1), on which I interpolate the function v, although I am not really satisfied with the outcome.

Thank you in advance for the help,
Best regards,
Luca

-- 
Dr. Luca Mechelli
Wissenschaftlicher Mitarbeiter
Arbeitsgruppe Numerik
Fachbereich Mathematik und Statistik

Universität Konstanz
Fach D 198
D-78464 Konstanz
Telefon: +49-(0) 7531-88-3646