dolfin team mailing list archive

[Ola Skavhaug <skavhaug@xxxxxxxxx>]

Anders Logg skrev den 10/04-2008 følgende:
> On Thu, Apr 10, 2008 at 06:19:59PM +0200, Martin Sandve Alnæs wrote:
> > I've been debugging some boundary condition trouble with the
> > syfi/pydolfin combination and vector elements, and narrowed it down to
> > the interpolate function which is used prior to plotting.
> > 
> > The bug is in the assumed numbering of the vertex_values array as
> > returned by ufc::finite_element::interpolate_vertex_values:
> > 
> > void DiscreteFunction::interpolate(real* values) const
> > {
> > ...
> > 
> >     // Copy values to array of vertex values
> >     for (VertexIterator vertex(*cell); !vertex.end(); ++vertex)
> >       for (uint i = 0; i < scratch->size; ++i)
> >         values[i*mesh.numVertices() + vertex->index()] =
> > vertex_values[i*num_cell_vertices + vertex.pos()];
> > 
> > 
> > By the UFC definition this should've been:
> > 
> > vertex_values[vertex.pos()*scratch->size + i];
> > 
> > i.e. the vector components are collected together in memory for each
> > vertex. This bug must be mirrored in FFC, and should be fixed both
> > places at once.
> > 
> > I'll let someone with write access to FFC and DOLFIN fix it.
> 
> Then should we also change the order Viper expects to receive the
> values?

Sure. You update stuff, I'll make it work with Viper later.

Ola
 
> It would be good to have the same order everywhere.
> 
> -- 
> Anders
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