dolfin team mailing list archive

[Dag Lindbo <dag@xxxxxxxxxx>]

Hello Dolfin!

Currently, one may not initialize a DiscreteFunction with something like 
init(Mesh&, Form&, uint). All init-methods involve also a 
GenericVector&. I think it would be useful to have a init-method that 
uses only the form and mesh, which then allocates a vector for itself 
(so that the DiscreteFunction actually "owns" its own dofs). Or is there 
a particular reason not to allow this?

Why do I care? I'm looking at the current state of the LinearPDE class. 
Here, the solution vector is a member function, and the solution 
Function is initialized with a reference to this vector. I.e. the 
LinearPDE (not the DiscreteFunction) owns the solution vector. This is 
of course a problem if the LinearPDE goes out of scope before the 
solution function (bug 24). It is also a bit counter-intuitive.

If it was possible to do an initialization like above, then the solve() 
method would simply do
u.init(mesh, form, 1);
GenericVector& x = u.vector();
<solve>

/Dag