dolfin team mailing list archive

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

Anders Logg wrote:
> On Mon, Feb 16, 2009 at 11:44:04AM +0000, Garth N. Wells wrote:
> > Anders Logg wrote:
> > > On Mon, Feb 16, 2009 at 11:30:46AM +0000, Garth N. Wells wrote:
> > > > Anders Logg wrote:
> > > > > On Mon, Feb 16, 2009 at 11:52:54AM +0100, Johan Hake wrote:
> > > > > > On Monday 16 February 2009 11:31:36 Anders Logg wrote:
> > > > > > > On Mon, Feb 16, 2009 at 10:12:21AM +0000, Garth N. Wells wrote:
> > > > > > > > Anders Logg wrote:
> > > > > > > > > On Mon, Feb 16, 2009 at 10:36:52AM +0100, Johan Hake wrote:
> > > > > > > > > > On Sunday 15 February 2009 21:23:44 DOLFIN wrote:
> > > > > > > > > > > One or more new changesets pushed to the primary dolfin repository.
> > > > > > > > > > > A short summary of the last three changesets is included below.
> > > > > > > > > > >
> > > > > > > > > > > changeset:   5701:d3661203791d9c7707695c59adbbd3a2e20a220c
> > > > > > > > > > > tag:         tip
> > > > > > > > > > > user:        Anders Logg <logg@xxxxxxxxx>
> > > > > > > > > > > date:        Sun Feb 15 21:23:36 2009 +0100
> > > > > > > > > > > files:       dolfin/function/Function.cpp
> > > > > > > > > > > description:
> > > > > > > > > > > Move code from Function copy constructor to assignment operator and
> > > > > > > > > > > call assignment operator from copy constructor
> > > > > > > > > > I liked Garth solution better.
> > > > > > > > > >
> > > > > > > > > >  1) A copy constructor that, just copies the Function if it has
> > > > > > > > > >     a FunctionSpace.
> > > > > > > > > >  2) The assignment operator works only for discrete Functions.
> > > > > > > > > >
> > > > > > > > > > We could add an interpolate() (or something) function that
> > > > > > > > > >
> > > > > > > > > >   v.interpolate(*_vector, *_function_space);
> > > > > > > > > We already have exactly such a function.
> > > > > > Do we?
> > > > > Yes:
> > > > >
> > > > >   /// Interpolate function to given function space
> > > > >   void interpolate(GenericVector& coefficients, const FunctionSpace& V) const;
> > > > >
> > > > > > > > > > Then the user can explicitly create a discrete function of its
> > > > > > > > > > user-defined Function. Now the user gets this as an implicitly result
> > > > > > > > > > of a function copy, which make litle sense to me.
> > > > > > > > > >
> > > > > > > > > > But that's just me :)
> > > > > > > > > I like it. Other opinions?
> > > > > > > > It is neat, but I would prefer any interpolation to be more explicit so
> > > > > > > > that it's clear what's going on. A copy should be a straight copy.
> > > > > > > >
> > > > > > > > Garth
> > > > > > > ok. I've changed it back. See if it looks ok.
> > > > > > Now a user cannot copy a Function that is not a discrete function, which was 
> > > > > > the case before we started all this. 
> > > > > Wasn't that the point? It's not possible to copy the eval() operator.
> > > > It is if a MyFunction object is copied to a MyFunction object, which we 
> > > > couldn't do before. My change made this possible.
> > > >
> > > > Garth
> > > What's the point of that? It's like copying half a Function.
> > No, it's a copy.
>
> Only when assigning between two MyFunction objects.
>
> > > If I do
> > >
> > >   v = w;
> > >
> > > I expect v to be in everything essential the same as w.
> > If you do
> >
> >    MyFuncion f0;
> >    MyFunction f1 = f0;
> >
> > f0 and and f1 will be the same. The assignment operator is a separate story.
>
> What if you do 
>
>   MyFunction f0;
>   MyOtherFunction f1 = f0;
>
> ?

I expect that you'll get an error when you try to call eval().

Garth

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