On Tuesday 04 November 2008 19:59:35 Johan Hake wrote: > On Tuesday 04 November 2008 19:45:10 Martin Sandve Alnæs wrote: > > 2008/11/4 Johan Hake <[EMAIL PROTECTED]>: > > > On Tuesday 04 November 2008 15:00:42 Martin Sandve Alnæs wrote: > > >> 2008/11/4 Johan Hake <[EMAIL PROTECTED]>: > > >> > On Tuesday 04 November 2008 13:59:22 Martin Sandve Alnæs wrote: > > >> >> 2008/11/4 Johan Hake <[EMAIL PROTECTED]>: > > >> >> > On Tuesday 04 November 2008 13:07:07 Martin Sandve Alnæs wrote: > > >> >> >> 2008/11/4 Johan Hake <[EMAIL PROTECTED]>: > > >> >> >> > Hello! > > >> >> >> > > > >> >> >> > I have started the work on the PyDOLFIN. We can now define the > > >> >> >> > forms in the poisson demo, using the syntax previously > > >> >> >> > discussed, see python poisson demo. > > >> >> >> > > > >> >> >> > A FunctionSpace now inherits both dolfin::FunctionSpace and > > >> >> >> > ffc.FiniteElement, and it can be used to instantiate user > > >> >> >> > defined Functions which can be used to define forms. > > >> >> >> > > > >> >> >> > We need to discuss how to implement a discrete function. This > > >> >> >> > is a bit complicated using the metaclass magic that is > > >> >> >> > implemented now. Now we cannot do: > > >> >> >> > > > >> >> >> > u = Function(V) > > >> >> >> > x = u.vector() > > >> >> >> > > > >> >> >> > as Function is just a dummy class for creation of userdefined > > >> >> >> > functions. > > >> >> > > >> >> I don't quite understand the problem here. > > >> >> Are you saying that type(u) is not a subclass of cpp_Function or > > >> >> what? > > >> > > > >> > With the metaclass implementation, Function cannot inherit > > >> > cpp_Function or ffc.Function. A derived class of Function will > > >> > inherit Function, cpp_Function and ffc.Function though. Function is > > >> > as it is now, only an more or less empty class that can be > > >> > inherited. > > >> > > > >> > The syntax above can be valid with some __new__ magic in Function, > > >> > probably much in line with what you had in mind. > > >> > > >> But in the metaclass __new__ function you have explicit control of the > > >> bases of the new class you're building, so where's the problem? > > >> Just set bases = (cpp_Function, ufl.Function). > > > > > > Of course. When I wrote the code I never intended Function to be > > > instantiated. > > > > Sure. With the new Function design that will of course happen all the > > time. > > > > > Would it make sense to always create a Function that is discrete when > > > we just write, u = Function(V)? > > > > Yes, just like cpp_Function(V). Anything else would be insane :-) > > > > By the way, this gives a segmentation fault: > > > > from dolfin import * > > mesh = UnitSquare(2,2) > > V = FunctionSpace(mesh, "CG", 1) > > u = cpp_Function(V) > > v = u.vector() > > > > Happy debugging :-/ > > The same to you ;) > > Urgh... I used two hours to track a similare bug yesterday. It was a > forgotten NoDeleter to a shared pointer that caused the havoc.
Ok, this one also took some time... The local dolfin::DofMap, dolfin::FiniteElement, ufc::DofMap and ufc::FiniteElement are all destroyed by python when FunctionSpace.__init__ is left. Is it safe to set thisown = 0? It fixes the problem, but will it be destroyed when the pyhton program end? We could also store a reference to them locally a la, FunctionSpace.__dofmap or we could also store them in a global list in the function.py module. Any comments? Johan _______________________________________________ DOLFIN-dev mailing list [email protected] http://www.fenics.org/mailman/listinfo/dolfin-dev
