dolfin team mailing list archive

[Andre Massing <massing@xxxxxxxxx>]

Den 22.11.10 20.44, skrev Anders Logg:
> The problem is you are calling the wrong assemble function. Look in
> assemble.h. You are calling this function:
>
>    double assemble(const Form&  a,
>                    bool reset_sparsity=true,
>                    bool add_values=false);
>
> and the pointer of the marker is interpreted as a boolean.
>
> You want this function:
>
>    double assemble(const Form&  a,
>                    const MeshFunction<uint>* cell_domains,
>                    const MeshFunction<uint>* exterior_facet_domains,
>                    const MeshFunction<uint>* interior_facet_domains,
>                    bool reset_sparsity=true,
>                    bool add_values=false);
>
> Change to
>
>    norm = assemble(one_norm,&half_space_marker, 0, 0);
>
> and it should work.
>
> --
> Anders
>
>
>
> On Mon, Nov 22, 2010 at 08:36:19PM +0100, Andre Massing wrote:
> > Den 22.11.10 18.39, skrev Anders Logg:
> > > On Mon, Nov 22, 2010 at 05:45:07PM +0100, Andre Massing wrote:
> > > > Den 22.11.10 17.40, skrev Johan Hake:
> > > > > On Monday November 22 2010 07:36:25 Andre Massing wrote:
> > > > > > Hi!
> > > > > >
> > > > > > I am not entirely sure, whether there was a similar discussion about that,
> > > > > >    but I just recognized that using a ufl file like
> > > > > >
> > > > > > element = FiniteElement("Lagrange","tetrahedron", 1)
> > > > > > w = Coefficient(element)
> > > > > > M = w*w*dx(0)
> > > > > >
> > > > > > and a meshfunction with 0, 1, 2 values
> > > > > > results into the assembly of a function on *entire* domain and not only
> > > > > > cells that a marked with 0.
> > > > > > Can anybody confirm this behaviour?
> > > Take a look in Assembler.cpp in the function assemble_cells. It should
> > > be quite easy to find what goes wrong with some suitable print
> > > statements. Look for the if-statements starting with
> > >
> > >    if (domain&&   domains->size()>   0)
> > I cannot really find the culprit code snippets. Either I am
> > completely blind right now, or it is rather strange...
> > I have an example where I use a subdomain directly (meaning a
> > SubDomain class instance) in the assemble
> > routine and then indirectly, via marking a meshfunction via
> > subdomain (which is the what the assemble function
> > does it internally). This gives different result and I cannot see why.
> > Code is attached...
> >
> > #Form to compile L^2.
> >
> > element = FiniteElement("Lagrange","tetrahedron", 1)
> > w = Coefficient(element)
> > M = w*w*dx(0)
> > element = FiniteElement("Lagrange", "tetrahedron", 1)
> >
> > v = TestFunction(element)
> > u = TrialFunction(element)
> > f = Coefficient(element)
> >
> > a = inner(grad(v), grad(u))*dx
> > L = v*f*dx
> > #include "L2_norm.h"
> > #include "Poisson.h"
> > #include<dolfin.h>
> >
> > using namespace dolfin;
> >
> > class HalfSpace : public SubDomain
> > {
> >    bool inside(const Array<double>&  x, bool on_boundary) const
> >    {
> >      return x[0]<  0.5 + DOLFIN_EPS;
> >    }
> > };
> >
> >
> > int main()
> > {
> >      UnitCube mesh0(5,5,5);
> >
> >      HalfSpace half_space;
> >      MeshFunction<uint>  half_space_marker(mesh0, mesh0.topology().dim(),1);
> >      half_space.mark(half_space_marker,0);
> >      info(half_space_marker.str(true));
> >
> >      Poisson::FunctionSpace V0(mesh0);
> >      Function one(V0);
> >      one.interpolate(Constant(1));
> >
> >      L2_norm::Functional one_norm(mesh0,one);
> >
> >      double norm;
> >      norm = assemble(one_norm,half_space);
> >      info("Integral of 1 is %e:", norm);
> >
> >      norm = assemble(one_norm,&half_space_marker);
> >      info("Integral of 1 is %e:", norm);
> >
> >
> >      return 0;
> > }
Yes, that was, thanks a lot, I was implicitly assuming default values 
for the mesh_function pointers, don't really know why..
BTW, can you see your emails you send to mailing lists you subscribe to ?
gmail does somehow filter out my messages :( very annoying...
--
Andre

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