dolfin team mailing list archive

["Garth N. Wells" <gnw20@xxxxxxxxx>]

On 22 November 2011 21:30, Anders Logg <logg@xxxxxxxxx> wrote:
> 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?
>

I don't think that is ideal.

I building now with the constructors commented out to see how many
changes would be required.

Garth

> --
> Anders
>