dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Tue, Nov 22, 2011 at 10:16:54PM +0100, Marie E. Rognes wrote:
> 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.

Is everyone ok with throwing an error that it doesn't work in
parallel?

--
Anders