dolfin team mailing list archive

["Marie E. Rognes" <meg@xxxxxxxxx>]

On 11/22/2011 09:55 PM, Anders Logg wrote:
> On Tue, Nov 22, 2011 at 08:45:30PM +0000, Garth N. Wells wrote:
> > On 21 Nov 2011, at 21:53, "Marie E. Rognes"<meg@xxxxxxxxx>  wrote:
> >
> > > On 21. nov. 2011, at 21:52, Anders Logg<logg@xxxxxxxxx>  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()?
> > > Probably. However removing the constructor would be changing parts of the basic interface, which I think is a bad idea.
> > >
> > > Add a warning if you want to deprecate it later.
> > Isn't the time to make an interface change now rather than later?

I would say that the time to make an interface change before
1.0 has passed: I see more value in sticking to
to what we have claimed, than in fixing this single instance.

> True, but last time we discussed this was 1 hour or so before the
> release of 1.0-rc1. Now we have a whole week to 1.0-rc2... :-)
>
> Marie, can you check again if that constructor is necessary?

I'm typically using it for the same as the dolfin la/eigenvalue demo is 
using it for.
Do you have a replacement syntax available?

That said, I'm not going to lose any sleep over this.

--
Marie