dolfin team mailing list archive

[Ola Skavhaug <skavhaug@xxxxxxxxx>]

Martin Sandve Alnæs skrev den 10/04-2008 følgende:
> 2008/4/10, 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
> 
> What does VTK expect?
 
In general, it is described here:
www.vtk.org/pdf/file-formats.pdf 

Ola

> --
> Martin