dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

Just do the following:

Mesh mesh; Function f;

real* vertex_values = new real[mesh.numVertices()];
f.interpolate(vertex_values);

Then vertex_values will be an array with the values at all vertices.

For a scalar function, you simply get all the vertex values and for a 
vector (or in general tensor-valued) function, you first get all the 
values for component 0, then all values for component 1 etc.

/Anders


Alessio Quaglino wrote:
> > On Tue, Jun 26, 2007 at 02:56:52PM +0200, Alessio Quaglino wrote:
> > > I'm trying to get my code working with the new dolfin 0.7.0-1 but it
> > > seems
> > > there are a several problems. For example, a part of the
> > > dolfin::Function
> > > interface has disappeared. In particular, it is not possible to get the
> > > value corresponding to a vertex or the finite element space where the
> > > function is living. Have these functionalities been moved somewhere
> > > else?
> > >
> > > Regards,
> > > Alessio Quaglino
> > Use Function::interpolate() to access the values. Often, one can
> > avoid ever needing to access the values directly, but if they should
> > be needed, then it is possible to either interpolate the Function to a
> > given Cell (getting the expansion coefficients in the local finite
> > element basis) or get the values at all vertices.
> >
> > So, try to avoid accessing the values but if you really need the
> > values at vertices you can still get them.
> >
> > /Anders
> > _______________________________________________
> > DOLFIN-dev mailing list
> > DOLFIN-dev@xxxxxxxxxx
> > http://www.fenics.org/mailman/listinfo/dolfin-dev
>
> Ok I see, however with interpolate() I can either get all the Vertex
> values or the values at a given Cell. While the latter case is unefficient
> for my purpose  because I'd pass through the same Vertex several times, in
> the former I get a vector with the values at all vertices but no
> information about how to access such a vector.
>
> Regards,
> Alessio
>
>
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