There is no support for mixed spaces over different space (yet). It may or may not appear in some later version, but don't hold your breath.
Martin On 24 May 2014 08:23, André Timótheo <[email protected]> wrote: > Hi, > > I need some help. > > I can not understand the relationship of global functions in mixed > functions spaces of *two different meshes* on the assembled system > matrix. > > The code below illustrates my point. > > from dolfin import * > > mesh1 = UnitIntervalMesh(4) > mesh2 = UnitIntervalMesh(2) > > V1 = FunctionSpace(mesh1, "CG", 2) # 9 Lagrange *global* functions > of degree 2 > V2 = FunctionSpace(mesh2, "CG", 1) # 3 Lagrange *global* functions > of degree 1 > > V = V1 * V2 > > (u1, u2) = TrialFunctions(V) > v1 = TestFunction(V1) > > a = (inner(grad(u1), grad(v1)) * dx) + (inner(grad(u2), grad(v1)) * > dx) > > A = assemble(a) > > V1_dofs = V.sub(0).collapse(mesh1)[1].values() > V2_dofs = V.sub(1).collapse(mesh2)[1].values() > > print 'V1 dofs = ', V1_dofs > print 'V2 dofs = ', V2_dofs > > print 'A = ', A.array() > > I would expect to find three V2 dofs associated with the functions of > space V2. Mesh2 has only 3 nodes. But there are five V2 dofs = [4, 2, 6, 9, > 13]. There is no problem with V1 dofs = [0, 1, 3, 5, 7, 8, 10, 11, 12]. > There are 5 mesh nodes and the midpoints of its elements. The assembled > system matrix do not have 12 columns. > > I can t understand it. Any help will be appreciated. Thanks for > availability. > Andre Machado > > > p.s.: I disturb the FEniCS q&a first... > > > http://fenicsproject.org/qa/3561/dof-map-of-mixed-space-over-different-meshes > > This is from line 483 of site-packages/functions/functionspace.py: > > * #if not all(V.mesh() == spaces[0].mesh() for V in spaces): > # cpp.dolfin_error("functionspace.py", "Nonmatching meshes for mixed > function space: " \ > # + str([V.mesh() for V in spaces]))* > > > > _______________________________________________ > fenics mailing list > [email protected] > http://fenicsproject.org/mailman/listinfo/fenics > >
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