dolfin team mailing list archive

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

Marie Rognes wrote:
> Garth N. Wells wrote:
> > Marie Rognes wrote:
> > > The following code gives r = 0.0. It is not supposed to be.
> > >
> > > The problem seems to be that f's vector is still all zeros at the call
> > > to interpolate. Could this be easily fixed?
> >
> > This example should have led to an error message since f is not a 
> > discrete function. I'll take a look.
>
> Ok, thanks!
>
> However,
>
> (a) Why is f not a discrete function? (It is defined on a finite element 
> space?)

On second thought, it may be a discrete function. I think that this is 
defined in the Python interface and not the C++ interface, so I'll take 
a look.

> (b) I would very much like this not to give an error, but rather work ;) 
> I would use something like this all the time when checking convergence.

Just do

  f.interpolate()

Garth

> --
> Marie
>
>
> > Garth
> >
> > > --
> > > from dolfin import *
> > >
> > > mesh = UnitSquare(1,1)
> > > V_h = FunctionSpace(mesh, "CG", 1)
> > > f = Function(V_h, "1.0")
> > >
> > > Q_h = FunctionSpace(mesh, "DG", 1)
> > > Pi_f = interpolate(f, Q_h)
> > >
> > > r = norm(Pi_f)
> > > print "r = ", r
> > > ---
> > >
> > > --
> > > Marie
> > >
> > >
> > > _______________________________________________
> > > DOLFIN-dev mailing list
> > > DOLFIN-dev@xxxxxxxxxx
> > > http://www.fenics.org/mailman/listinfo/dolfin-dev