static void GenerateMatrix (const FEL & bfel, const MIP & mip,
MAT & mat, LocalHeap & lh)
{
// must get the right elements, otherwise an exception is thrown.
const CompoundFiniteElement & cfel =
dynamic_cast<const CompoundFiniteElement&> (bfel);
// a scalar H1 element
const ScalarFiniteElement<2> & fel_u =
dynamic_cast<const ScalarFiniteElement<2>&> (cfel[0]);
const ScalarFiniteElement<2> & fel_p =
dynamic_cast<const ScalarFiniteElement<2>&> (cfel[2]);
int nd_u = fel_u.GetNDof();
int nd_p = fel_p.GetNDof();
// transformation of derivatives from reference element to general element:
FlatMatrixFixWidth<2> gradu(nd_u, lh);
fel_u.CalcMappedDShape (mip, gradu);
// the shape functions of the pressure
FlatVector<> vecp(nd_p, lh);
fel_p.CalcShape (mip.IP(), vecp);
mat = 0;
// the first nd_u shape functions belong to u_x, the next nd_u belong to u_y:
mat.Rows(0,2).Cols(cfel.GetRange(0)) = Trans (gradu);
mat.Rows(2,4).Cols(cfel.GetRange(1)) = Trans (gradu);
// ... and finally nd_p shape functions for the pressure:
mat.Row(4).Range(cfel.GetRange(2)) = vecp;
}
static void GenerateMatrix (const FEL & bfel, const MIP & mip,
MAT & mat, LocalHeap & lh)
{
const CompoundFiniteElement & cfel =
dynamic_cast<const CompoundFiniteElement&> (bfel);
const ScalarFiniteElement<2> & fel_u =
dynamic_cast<const ScalarFiniteElement<2>&> (cfel[0]);
int nd_u = fel_u.GetNDof();
FlatVector<> vecu(nd_u, lh);
fel_u.CalcShape (mip.IP(), vecu);
mat = 0;
mat.Row(0).Range(cfel.GetRange(0)) = vecu;
mat.Row(1).Range(cfel.GetRange(1)) = vecu;
}
