dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Mon, Nov 21, 2011 at 09:52:53PM +0100, Anders Logg wrote:
> On Mon, Nov 21, 2011 at 08:46:13PM +0000, Garth N. Wells wrote:
> > On 21 November 2011 13:07, Anders Logg <logg@xxxxxxxxx> wrote:
> > > On Sun, Nov 20, 2011 at 11:55:43PM +0100, Anders Logg wrote:
> > >> On Sun, Nov 20, 2011 at 11:49:42PM +0100, Marie E. Rognes wrote:
> > >> >
> > >> >
> > >> > On 20. nov. 2011, at 23:31, Anders Logg <logg@xxxxxxxxx> wrote:
> > >> >
> > >> > > Is anyone using the Function constructor that takes a vector as input
> > >> > > argument?
> > >> > >
> > >> > >  Function u(V, x);
> > >> > >
> > >> >
> > >> > Yes.
> > >>
> > >> Does it work? In parallel?
> > >>
> > >> Does it not work to instead use
> > >>
> > >>   x = u.vector()
> > >>
> > >> ?
> > >>
> > >> If you need it, we should keep it but add an error message that it
> > >> doesn't work in parallel, unless it does...
> > >
> > > Any more input on this? There are several options:
> > >
> > > 1. Remove this constructor
> > >
> > > 2. Throw an error when running in parallel
> > >
> > > 3. Check that the input vector makes sense
> > >
> > > The last one is problematic since I don't see an easy way to perform
> > > the check, other than calling get_local and having it fail.
> > >
> >
> > I haven't heard any reason why it can't be removed. We may need to fix
> > assignment (re earlier discussion on assign) to just copy values and
> > not the whole object so that a user can get the vector and then assign
> > values to it without messing up the ghosting.
>
> Sounds good, but I want to wait for Marie to comment before I remove
> it. She is using it.
>
> Marie? Does it work for you to use x = u.vector()?

I'm thinking now that it's a bit late to change the interface of the
Function class, so I suggest we keep that constructor and later either
make sure to fix it (check that the incoming vector is correct), or
disable it in parallel or just slap a warning that the user (Marie) is
on her own if deciding to supply the vector herself.

--
Anders