Johan Hake wrote: > On Sunday 18 October 2009 16:43:28 Garth N. Wells wrote: >> Garth N. Wells wrote: >>> Johan Hake wrote: >>>> On Saturday 17 October 2009 21:08:14 Garth N. Wells wrote: >>>>> Garth N. Wells wrote: >>>>>> DOLFIN wrote: >>>>>>> One or more new changesets pushed to the primary dolfin repository. >>>>>>> A short summary of the last three changesets is included below. >>>>>>> >>>>>>> changeset: 7378:e5c921e0293a >>>>>>> tag: tip >>>>>>> user: "Johan Hake <h...@simula.no>" >>>>>>> date: Sat Oct 17 15:45:36 2009 +0200 >>>>>>> files: site-packages/dolfin/function.py >>>>>>> site-packages/dolfin/functionspace.py description: >>>>>>> Make Mixed FunctionSpace access more consistant. >>>>>>> - All methods are now defined in FunctionSpaceBase. >>>>>>> - We now do not save any spaces in MixedFunctionSpace >>>>>> This change broke my code. See below. >>>>> Seems that the problem arises with spaces which are restricted, >>>>> >>>>> V = FunctionSpace(mesh, "CG", 1, "facet") >>>> This is an error in the generated FFC code. >>>> ufc::finite_element::signature() >>>> should return a string that can be executed in a ufl namespace and >>>> then generate the corresponding ufl.FiniteElement. >>>> >>>> For a restricted element the signature returns: >>>> >>>> "FiniteElement('Lagrange', 'triangle', 1)|_{<interval of degree 1>}" >>>> >>>> where it should return: >>>> >>>> "ElementRestriction(FiniteElement('Lagrange', Cell('triangle', 1, >>>> Space(2)), 1), Cell('interval', 1, Space(1)))" >> I've had a look, and while I don't yet follow where UFL defines its >> signatures, > > repr(ulf_object) > > returns the uniqe signature of an ufl_object. > >> things are dangerous because FFC formats its own signature >> strings, see line 227 of >> >> ffc/ffc/fem/finiteelement.py > > Yes, this is dangerous, at least if we want to use them as we do in PyDOLFIN. > However taking repr of the corresponding ufl object is a well defined method > that ufl use internally, when for example creating a unique string > representation of a form. > >> We stopped using signature strings in DOLFIN because it gave us all >> sorts of problems. Is it desirable to have PyDOLFIN depend on the >> generated strings? Can it be avoided? > > It is a very nice way of constructing an ufl object when we have the compiled > version. As the convention of repr(object) is that: > > new_object = eval(repr(object)) > > should return a new object of the same kind. > > So when we have a SubSpace with its compiled FiniteElement, it is easy to > just > call its signature method of its element to generate the corresponding ufl > element, which is used to construct a full fledged dolfin.FunctionSpace. > > Not sure how this could be done another way. >
Can't we get the sub-element from the original UFL function? If I do (u0, u1) = pde.solve().split() are u0 and u1 UFL Functions, or just cpp Functions? > Isn't it possible to use what repr(ufl_element) returns to define the > signature of an element or isn't the ufl_element available in > ffc.FiniteElement? > Yes. I committed this change to FFC a short while ago. Garth > Johan > >>> If I look at the generated code in Poisson.h (the DOLFIN demo), the >>> signature is >>> >>> "FiniteElement('Lagrange', 'triangle', 1)" >>> >>> so the restricted one looks consistent to me. How does PyDOFLIN use the >>> signature? >>> >>> Garth >>> >>>> Johan >>>> >>>>> Garth >>>>> >>>>>> Garth >>>>>> >>>>>> File "solver.py", line 96, in solve >>>>>> (uhat, uu) = Uh.split() >>>>>> File >>>>>> "/home/garth/code/fenics/dolfin/dolfin-all/local/lib/python2.6/site-pa >>>>>> cka >>>>>> >>>>>> ges/dolfin/function.py", line 150, in split >>>>>> return tuple(self._sub(i,deepcopy) for i in >>>>>> xrange(self._V.num_sub_spaces())) >>>>>> File >>>>>> "/home/garth/code/fenics/dolfin/dolfin-all/local/lib/python2.6/site-pa >>>>>> cka >>>>>> >>>>>> ges/dolfin/function.py", line 150, in <genexpr> >>>>>> return tuple(self._sub(i,deepcopy) for i in >>>>>> xrange(self._V.num_sub_spaces())) >>>>>> File >>>>>> "/home/garth/code/fenics/dolfin/dolfin-all/local/lib/python2.6/site-pa >>>>>> cka >>>>>> >>>>>> ges/dolfin/function.py", line 135, in _sub >>>>>> return Function(self, i) >>>>>> File >>>>>> "/home/garth/code/fenics/dolfin/dolfin-all/local/lib/python2.6/site-pa >>>>>> cka >>>>>> >>>>>> ges/dolfin/function.py", line 80, in __init__ >>>>>> self._V = V.sub(i) >>>>>> File >>>>>> "/home/garth/code/fenics/dolfin/dolfin-all/local/lib/python2.6/site-pa >>>>>> cka >>>>>> >>>>>> ges/dolfin/functionspace.py", line 88, in sub >>>>>> return FunctionSpaceFromCpp(cpp.SubSpace(self,i)) >>>>>> File >>>>>> "/home/garth/code/fenics/dolfin/dolfin-all/local/lib/python2.6/site-pa >>>>>> cka >>>>>> >>>>>> ges/dolfin/functionspace.py", line 101, in __init__ >>>>>> self._ufl_element = eval(cppV.element().signature(), >>>>>> ufl.__dict__) File "<string>", line 1 >>>>>> FiniteElement('Lagrange', 'triangle', 1)|_{<interval of degree >>>>>> 1>} >>>>>> >>>>>>> changeset: 7377:40cca61143c6 >>>>>>> user: "Garth N. Wells <gn...@cam.ac.uk>" >>>>>>> date: Sat Oct 17 13:24:47 2009 +0100 >>>>>>> files: dolfin/mesh/SubDomain.h >>>>>>> description: >>>>>>> Small formatting fix. >>>>>>> >>>>>>> >>>>>>> changeset: 7376:8ee974ed5f7e >>>>>>> user: Anders Logg <l...@simula.no> >>>>>>> date: Sat Oct 17 00:05:34 2009 +0200 >>>>>>> files: dolfin/function/Function.cpp >>>>>>> description: >>>>>>> Remove unnecessary lines in Function::eval noted by Marc S. >>>>>>> >>>>>>> --------------------------------------------------------------------- >>>>>>> - For more details, visit http://www.fenics.org/hg/dolfin >>>>>>> _______________________________________________ >>>>>>> DOLFIN-dev mailing list >>>>>>> DOLFIN-dev@fenics.org >>>>>>> http://www.fenics.org/mailman/listinfo/dolfin-dev >>>>>> _______________________________________________ >>>>>> DOLFIN-dev mailing list >>>>>> DOLFIN-dev@fenics.org >>>>>> http://www.fenics.org/mailman/listinfo/dolfin-dev >>>>> _______________________________________________ >>>>> DOLFIN-dev mailing list >>>>> DOLFIN-dev@fenics.org >>>>> http://www.fenics.org/mailman/listinfo/dolfin-dev _______________________________________________ DOLFIN-dev mailing list DOLFIN-dev@fenics.org http://www.fenics.org/mailman/listinfo/dolfin-dev