dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Wed, Jun 15, 2011 at 01:51:08PM +0200, Anders Logg wrote:
> On Wed, Jun 15, 2011 at 01:50:07PM +0200, Martin Sandve Alnæs wrote:
> > Not sure, will have to get back to that.
>
> ok.
>
> > But wether we can use (a==L), (J==-F), (F==0) or just (a, L), (J, -F), (F, 0)
> > is basically a purely aestetic difference with no functional difference.
> > So the rest of the discussion can continue independently of this.
>
> Yes.

Martin,

Any more thoughts on whether a == L and F == 0 can work with UFL?

To sum up, I think we are looking at the following two options:

1. fancy

Solver classes:

  solver = LinearVariationalSolver(a, L, ...)
  solver.solve()

  solver = NonlinearVariational(F, J, ...)
  solver.solve()

Free functions:

  solve(a == L, ...)
  solve(F == 0, J, ...)

The free functions call the solver classes.

2. less fancy

Solver classes: same as above

Free functions:

  solve(a, L, ...)
  solve(F, 0, J, ...)

Note that in both cases, we specify lhs = rhs which means the
distinction is no longer the order of arguments. One always specifies
first lhs, then rhs. And one can easily check for the expected rank of
the arguments and give sensible error messages.

--
Anders