#include <cmath>
#include <limits>
#include <set>
+#include <list>
DEAL_II_NAMESPACE_OPEN
// will be used
template <class DH,
template <int,int> class M_or_MC,
- int dim_>
+ int dim_>
static inline
void
do_interpolate_boundary_values (const M_or_MC<DH::dimension, DH::space_dimension> &mapping,
/**
* Add the constraint
- * $\vec n \cdot \vec u = 0$
+ * $\vec n \cdot \vec u = inhom$
* to the list of constraints.
*
* Here, $\vec u$ is represented
void
add_constraint (const VectorDoFTuple<dim> &dof_indices,
const Tensor<1,dim> &constraining_vector,
- ConstraintMatrix &constraints)
+ ConstraintMatrix &constraints,
+ const double inhomogeneity=0)
{
// choose the DoF that has the
constraints.add_entry (dof_indices.dof_indices[0],
dof_indices.dof_indices[1],
-constraining_vector[1]/constraining_vector[0]);
+
+ if (std::fabs (inhomogeneity/constraining_vector[0])
+ > std::numeric_limits<double>::epsilon())
+ constraints.set_inhomogeneity(dof_indices.dof_indices[0],
+ inhomogeneity/constraining_vector[0]);
}
}
else
constraints.add_entry (dof_indices.dof_indices[1],
dof_indices.dof_indices[0],
-constraining_vector[0]/constraining_vector[1]);
+
+ if (std::fabs (inhomogeneity/constraining_vector[1])
+ > std::numeric_limits<double>::epsilon())
+ constraints.set_inhomogeneity(dof_indices.dof_indices[1],
+ inhomogeneity/constraining_vector[1]);
}
}
break;
constraints.add_entry (dof_indices.dof_indices[0],
dof_indices.dof_indices[2],
-constraining_vector[2]/constraining_vector[0]);
+
+ if (std::fabs (inhomogeneity/constraining_vector[0])
+ > std::numeric_limits<double>::epsilon())
+ constraints.set_inhomogeneity(dof_indices.dof_indices[0],
+ inhomogeneity/constraining_vector[0]);
}
}
else if ((std::fabs(constraining_vector[1])+1e-10 >= std::fabs(constraining_vector[0]))
constraints.add_entry (dof_indices.dof_indices[1],
dof_indices.dof_indices[2],
-constraining_vector[2]/constraining_vector[1]);
+
+ if (std::fabs (inhomogeneity/constraining_vector[1])
+ > std::numeric_limits<double>::epsilon())
+ constraints.set_inhomogeneity(dof_indices.dof_indices[1],
+ inhomogeneity/constraining_vector[1]);
}
}
else
constraints.add_entry (dof_indices.dof_indices[2],
dof_indices.dof_indices[1],
-constraining_vector[1]/constraining_vector[2]);
+
+ if (std::fabs (inhomogeneity/constraining_vector[2])
+ > std::numeric_limits<double>::epsilon())
+ constraints.set_inhomogeneity(dof_indices.dof_indices[2],
+ inhomogeneity/constraining_vector[2]);
}
}
/**
- * Add the constraint $\vec u \|
+ * Add the constraint $(\vec u-\vec u_\Gamma) \|
* \vec t$ to the list of
* constraints. In 2d, this is a
* single constraint, in 3d these
*/
template <int dim>
void
- add_tangentiality_constraints (const VectorDoFTuple<dim> &dof_indices,
- const Tensor<1,dim> &tangent_vector,
- ConstraintMatrix &constraints)
+ add_tangentiality_constraints
+ (const VectorDoFTuple<dim> &dof_indices,
+ const Tensor<1,dim> &tangent_vector,
+ ConstraintMatrix &constraints,
+ const Vector<double> &b_values = Vector<double>(dim))
{
// choose the DoF that has the
// component 0 of the tangent
// vector t is largest by
// magnitude, then
- // x1=t[1]/t[0]*x_0, etc.
+ // x1=(b[1]*t[0]-b[0]*t[1])/t[0]+t[1]/t[0]*x_0, etc.
unsigned int largest_component = 0;
for (unsigned int d=1; d<dim; ++d)
if (std::fabs(tangent_vector[d]) > std::fabs(tangent_vector[largest_component]) + 1e-10)
constraints.add_entry (dof_indices.dof_indices[d],
dof_indices.dof_indices[largest_component],
tangent_vector[d]/tangent_vector[largest_component]);
+
+ const double inhomogeneity
+ = (b_values(d)*tangent_vector[largest_component]
+ -b_values(largest_component)*tangent_vector[d])
+ /tangent_vector[largest_component];
+
+ if (std::fabs(inhomogeneity)
+ > std::numeric_limits<double>::epsilon())
+ constraints.set_inhomogeneity(dof_indices.dof_indices[d],
+ inhomogeneity);
}
}
+ values[q_point] (first_vector_component + 1)
* tangentials[q_point] (1))
* (fe_values[vec].value (fe.face_to_cell_index (i, face), q_point)
- * tangentials[q_point]);
+ * tangentials[q_point])
+ / std::sqrt (jacobians[q_point][0][face_coordinate_direction[face]]
+ * jacobians[q_point][0][face_coordinate_direction[face]]
+ + jacobians[q_point][1][face_coordinate_direction[face]]
+ * jacobians[q_point][1][face_coordinate_direction[face]]);
if (q_point == 0)
dofs_processed[i] = true;
const std::set<types::boundary_id> &boundary_ids,
ConstraintMatrix &constraints,
const Mapping<dim, spacedim> &mapping)
+ {
+ ZeroFunction<dim>zero_function(dim);
+ typename FunctionMap<spacedim>::type function_map;
+ std::set<types::boundary_id>::const_iterator it
+ = boundary_ids.begin();
+ for (;it != boundary_ids.end(); ++it)
+ function_map[*it] = &zero_function;
+ compute_nonzero_normal_flux_constraints(dof_handler,
+ first_vector_component,
+ boundary_ids,
+ function_map,
+ constraints,
+ mapping);
+ }
+
+ template <int dim, template <int, int> class DH, int spacedim>
+ void
+ compute_nonzero_normal_flux_constraints (const DH<dim,spacedim> &dof_handler,
+ const unsigned int first_vector_component,
+ const std::set<types::boundary_id> &boundary_ids,
+ typename FunctionMap<spacedim>::type &function_map,
+ ConstraintMatrix &constraints,
+ const Mapping<dim, spacedim> &mapping)
{
Assert (dim > 1,
ExcMessage ("This function is not useful in 1d because it amounts "
// FE
hp::QCollection<dim-1> face_quadrature_collection;
for (unsigned int i=0; i<fe_collection.size(); ++i)
- {
-
const std::vector<Point<dim-1> > &
- unit_support_points = fe_collection[i].get_unit_face_support_points();
+ {
+ const std::vector<Point<dim-1> > &
+ unit_support_points = fe_collection[i].get_unit_face_support_points();
- Assert (unit_support_points.size() == fe_collection[i].dofs_per_face,
- ExcInternalError());
+ Assert (unit_support_points.size() == fe_collection[i].dofs_per_face,
+ ExcInternalError());
- face_quadrature_collection
- .push_back (Quadrature<dim-1> (unit_support_points));
- }
+ face_quadrature_collection.push_back (Quadrature<dim-1> (unit_support_points));
+ }
// now create the object with which we will generate the normal vectors
hp::FEFaceValues<dim,spacedim> x_fe_face_values (mapping_collection,
std::multimap<internal::VectorDoFTuple<dim>,
std::pair<Tensor<1,dim>, typename DH<dim,spacedim>::active_cell_iterator> >
DoFToNormalsMap;
+ std::map<internal::VectorDoFTuple<dim>, Vector<double> >
+ dof_vector_to_b_values;
DoFToNormalsMap dof_to_normals_map;
typename DH<dim,spacedim>::active_cell_iterator
cell = dof_handler.begin_active(),
endc = dof_handler.end();
+ std::set<types::boundary_id>::iterator b_id;
for (; cell!=endc; ++cell)
if (!cell->is_artificial())
for (unsigned int face_no=0; face_no < GeometryInfo<dim>::faces_per_cell;
++face_no)
- if (boundary_ids.find(cell->face(face_no)->boundary_indicator())
+ if ((b_id=boundary_ids.find(cell->face(face_no)->boundary_indicator()))
!= boundary_ids.end())
- {
- const FiniteElement<dim> &fe = cell->get_fe ();
- typename DH<dim,spacedim>::face_iterator face = cell->face(face_no);
+ {
+ const FiniteElement<dim> &fe = cell->get_fe ();
+ typename DH<dim,spacedim>::face_iterator face = cell->face(face_no);
- // get the indices of the dofs on this cell...
- face_dofs.resize (fe.dofs_per_face);
- face->get_dof_indices (face_dofs, cell->active_fe_index());
+ // get the indices of the dofs on this cell...
+ face_dofs.resize (fe.dofs_per_face);
+ face->get_dof_indices (face_dofs, cell->active_fe_index());
- x_fe_face_values.reinit (cell, face_no);
- const FEFaceValues<dim> &fe_values = x_fe_face_values.get_present_fe_values();
+ x_fe_face_values.reinit (cell, face_no);
+ const FEFaceValues<dim> &fe_values = x_fe_face_values.get_present_fe_values();
+
+ // then identify which of them correspond to the selected set of
+ // vector components
+ for (unsigned int i=0; i<face_dofs.size(); ++i)
+ if (fe.face_system_to_component_index(i).first ==
+ first_vector_component)
+ {
+ // find corresponding other components of vector
+ internal::VectorDoFTuple<dim> vector_dofs;
+ vector_dofs.dof_indices[0] = face_dofs[i];
+
+ Assert(first_vector_component+dim<=fe.n_components(),
+ ExcMessage("Error: the finite element does not have enough components "
+ "to define a normal direction."));
+
+ for (unsigned int k=0; k<fe.dofs_per_face; ++k)
+ if ((k != i)
+ &&
+ (face_quadrature_collection[cell->active_fe_index()].point(k) ==
+ face_quadrature_collection[cell->active_fe_index()].point(i))
+ &&
+ (fe.face_system_to_component_index(k).first >=
+ first_vector_component)
+ &&
+ (fe.face_system_to_component_index(k).first <
+ first_vector_component + dim))
+ vector_dofs.dof_indices[fe.face_system_to_component_index(k).first -
+ first_vector_component]
+ = face_dofs[k];
+
+ for (unsigned int d=0; d<dim; ++d)
+ Assert (vector_dofs.dof_indices[d] < dof_handler.n_dofs(),
+ ExcInternalError());
+
+ // we need the normal vector on this face. we know that it
+ // is a vector of length 1 but at least with higher order
+ // mappings it isn't always possible to guarantee that
+ // each component is exact up to zero tolerance. in
+ // particular, as shown in the deal.II/no_flux_06 test, if
+ // we just take the normal vector as given by the
+ // fe_values object, we can get entries in the normal
+ // vectors of the unit cube that have entries up to
+ // several times 1e-14.
+ //
+ // the problem with this is that this later yields
+ // constraints that are circular (e.g., in the testcase,
+ // we get constraints of the form
+ //
+ // x22 = 2.93099e-14*x21 + 2.93099e-14*x23
+ // x21 = -2.93099e-14*x22 + 2.93099e-14*x21
+ //
+ // in both of these constraints, the small numbers should
+ // be zero and the constraints should simply be
+ // x22 = x21 = 0
+ //
+ // to achieve this, we utilize that we know that the
+ // normal vector has (or should have) length 1 and that we
+ // can simply set small elements to zero (without having
+ // to check that they are small *relative to something
+ // else*). we do this and then normalize the length of the
+ // vector back to one, just to be on the safe side
+ //
+ // one more point: we would like to use the "real" normal
+ // vector here, as provided by the boundary description
+ // and as opposed to what we get from the FEValues object.
+ // we do this in the immediately next line, but as is
+ // obvious, the boundary only has a vague idea which side
+ // of a cell it is on -- indicated by the face number. in
+ // other words, it may provide the inner or outer normal.
+ // by and large, there is no harm from this, since the
+ // tangential vector we compute is still the same. however,
+ // we do average over normal vectors from adjacent cells
+ // and if they have recorded normal vectors from the inside
+ // once and from the outside the other time, then this
+ // averaging is going to run into trouble. as a consequence
+ // we ask the mapping after all for its normal vector,
+ // but we only ask it so that we can possibly correct the
+ // sign of the normal vector provided by the boundary
+ // if they should point in different directions. this is the
+ // case in tests/deal.II/no_flux_11.
+ Point<dim> normal_vector
+ = (cell->face(face_no)->get_boundary().normal_vector
+ (cell->face(face_no), fe_values.quadrature_point(i)));
+ if (normal_vector * fe_values.normal_vector(i) < 0)
+ normal_vector *= -1;
+ Assert (std::fabs(normal_vector.norm() - 1) < 1e-14,
+ ExcInternalError());
+ for (unsigned int d=0; d<dim; ++d)
+ if (std::fabs(normal_vector[d]) < 1e-13)
+ normal_vector[d] = 0;
+ normal_vector /= normal_vector.norm();
+
+ const Point<dim> point
+ = fe_values.quadrature_point(i);
+ Vector<double> b_values(dim);
+ function_map[*b_id]->vector_value(point, b_values);
+
+ // now enter the (dofs,(normal_vector,cell)) entry into
+ // the map
+ dof_to_normals_map.insert
+ (std::make_pair (vector_dofs,
+ std::make_pair (normal_vector,cell)));
+ dof_vector_to_b_values.insert
+ (std::make_pair(vector_dofs, b_values));
- // then identify which of them correspond to the selected set of
- // vector components
- for (unsigned int i=0; i<face_dofs.size(); ++i)
- if (fe.face_system_to_component_index(i).first ==
- first_vector_component)
- {
- // find corresponding other components of vector
- internal::VectorDoFTuple<dim> vector_dofs;
- vector_dofs.dof_indices[0] = face_dofs[i];
-
- Assert(first_vector_component+dim<=fe.n_components(),
- ExcMessage("Error: the finite element does not have enough components "
- "to define a normal direction."));
-
- for (unsigned int k=0; k<fe.dofs_per_face; ++k)
- if ((k != i)
- &&
- (face_quadrature_collection[cell->active_fe_index()].point(k) ==
- face_quadrature_collection[cell->active_fe_index()].point(i))
- &&
- (fe.face_system_to_component_index(k).first >=
- first_vector_component)
- &&
- (fe.face_system_to_component_index(k).first <
- first_vector_component + dim))
- vector_dofs.dof_indices[fe.face_system_to_component_index(k).first -
- first_vector_component]
- = face_dofs[k];
-
- for (unsigned int d=0; d<dim; ++d)
- Assert (vector_dofs.dof_indices[d] < dof_handler.n_dofs(),
- ExcInternalError());
-
- // we need the normal vector on this face. we know that it
- // is a vector of length 1 but at least with higher order
- // mappings it isn't always possible to guarantee that
- // each component is exact up to zero tolerance. in
- // particular, as shown in the deal.II/no_flux_06 test, if
- // we just take the normal vector as given by the
- // fe_values object, we can get entries in the normal
- // vectors of the unit cube that have entries up to
- // several times 1e-14.
- //
- // the problem with this is that this later yields
- // constraints that are circular (e.g., in the testcase,
- // we get constraints of the form
- //
- // x22 = 2.93099e-14*x21 + 2.93099e-14*x23
- // x21 = -2.93099e-14*x22 + 2.93099e-14*x21
- //
- // in both of these constraints, the small numbers should
- // be zero and the constraints should simply be
- // x22 = x21 = 0
- //
- // to achieve this, we utilize that we know that the
- // normal vector has (or should have) length 1 and that we
- // can simply set small elements to zero (without having
- // to check that they are small *relative to something
- // else*). we do this and then normalize the length of the
- // vector back to one, just to be on the safe side
- //
- // one more point: we would like to use the "real" normal
- // vector here, as provided by the boundary description
- // and as opposed to what we get from the FEValues object.
- // we do this in the immediately next line, but as is
- // obvious, the boundary only has a vague idea which side
- // of a cell it is on -- indicated by the face number. in
- // other words, it may provide the inner or outer normal.
- // by and large, there is no harm from this, since the
- // tangential vector we compute is still the same. however,
- // we do average over normal vectors from adjacent cells
- // and if they have recorded normal vectors from the inside
- // once and from the outside the other time, then this
- // averaging is going to run into trouble. as a consequence
- // we ask the mapping after all for its normal vector,
- // but we only ask it so that we can possibly correct the
- // sign of the normal vector provided by the boundary
- // if they should point in different directions. this is the
- // case in tests/deal.II/no_flux_11.
- Point<dim> normal_vector
- = (cell->face(face_no)->get_boundary()
- .normal_vector (cell->face(face_no),
- fe_values.quadrature_point(i)));
- if (normal_vector * fe_values.normal_vector(i) < 0)
- normal_vector *= -1;
- Assert (std::fabs(normal_vector.norm() - 1) < 1e-14,
- ExcInternalError());
- for (unsigned int d=0; d<dim; ++d)
- if (std::fabs(normal_vector[d]) < 1e-13)
- normal_vector[d] = 0;
- normal_vector /= normal_vector.norm();
-
- // now enter the (dofs,(normal_vector,cell)) entry into
- // the map
- dof_to_normals_map
- .insert (std::make_pair (vector_dofs,
- std::make_pair (normal_vector,
- cell)));
#ifdef DEBUG_NO_NORMAL_FLUX
- std::cout << "Adding normal vector:" << std::endl
- << " dofs=" << vector_dofs << std::endl
- << " cell=" << cell << " at " << cell->center() << std::endl
- << " normal=" << normal_vector << std::endl;
+ std::cout << "Adding normal vector:" << std::endl
+ << " dofs=" << vector_dofs << std::endl
+ << " cell=" << cell << " at " << cell->center() << std::endl
+ << " normal=" << normal_vector << std::endl;
#endif
- }
- }
+ }
+ }
// Now do something with the collected information. To this end, loop
// through all sets of pairs (dofs,normal_vector) and identify which
p = dof_to_normals_map.begin();
while (p != dof_to_normals_map.end())
- {
- // first find the range of entries in the multimap that corresponds to
- // the same vector-dof tuple. as usual, we define the range
- // half-open. the first entry of course is 'p'
- typename DoFToNormalsMap::const_iterator same_dof_range[2]
- = { p };
- for (++p; p != dof_to_normals_map.end(); ++p)
- if (p->first != same_dof_range[0]->first)
- {
- same_dof_range[1] = p;
- break;
- }
- if (p == dof_to_normals_map.end())
- same_dof_range[1] = dof_to_normals_map.end();
+ {
+ // first find the range of entries in the multimap that corresponds to
+ // the same vector-dof tuple. as usual, we define the range
+ // half-open. the first entry of course is 'p'
+ typename DoFToNormalsMap::const_iterator same_dof_range[2] = { p };
+ for (++p; p != dof_to_normals_map.end(); ++p)
+ if (p->first != same_dof_range[0]->first)
+ {
+ same_dof_range[1] = p;
+ break;
+ }
+ if (p == dof_to_normals_map.end())
+ same_dof_range[1] = dof_to_normals_map.end();
#ifdef DEBUG_NO_NORMAL_FLUX
- std::cout << "For dof indices <" << p->first << ">, found the following normals"
+ std::cout << "For dof indices <" << p->first << ">, found the following normals"
+ << std::endl;
+ for (typename DoFToNormalsMap::const_iterator
+ q = same_dof_range[0];
+ q != same_dof_range[1]; ++q)
+ std::cout << " " << q->second.first
+ << " from cell " << q->second.second
<< std::endl;
- for (typename DoFToNormalsMap::const_iterator
- q = same_dof_range[0];
- q != same_dof_range[1]; ++q)
- std::cout << " " << q->second.first
- << " from cell " << q->second.second
- << std::endl;
#endif
- // now compute the reverse mapping: for each of the cells that
- // contributed to the current set of vector dofs, add up the normal
- // vectors. the values of the map are pairs of normal vectors and
- // number of cells that have contributed
- typedef
- std::map
- <typename DH<dim,spacedim>::active_cell_iterator,
- std::pair<Tensor<1,dim>, unsigned int> >
+ // now compute the reverse mapping: for each of the cells that
+ // contributed to the current set of vector dofs, add up the normal
+ // vectors. the values of the map are pairs of normal vectors and
+ // number of cells that have contributed
+ typedef std::map<typename DH<dim,spacedim>::active_cell_iterator,
+ std::pair<Tensor<1,dim>, unsigned int> >
CellToNormalsMap;
- CellToNormalsMap cell_to_normals_map;
- for (typename DoFToNormalsMap::const_iterator
- q = same_dof_range[0];
- q != same_dof_range[1]; ++q)
- if (cell_to_normals_map.find (q->second.second)
+ CellToNormalsMap cell_to_normals_map;
+ for (typename DoFToNormalsMap::const_iterator
+ q = same_dof_range[0];
+ q != same_dof_range[1]; ++q)
+ if (cell_to_normals_map.find (q->second.second)
== cell_to_normals_map.end())
cell_to_normals_map[q->second.second]
= std::make_pair (q->second.first, 1U);
- else
- {
- const Tensor<1,dim> old_normal
+ else
+ {
+ const Tensor<1,dim> old_normal
= cell_to_normals_map[q->second.second].first;
- const unsigned int old_count
+ const unsigned int old_count
= cell_to_normals_map[q->second.second].second;
- Assert (old_count > 0, ExcInternalError());
+ Assert (old_count > 0, ExcInternalError());
- // in the same entry, store again the now averaged normal vector
- // and the new count
- cell_to_normals_map[q->second.second]
- = std::make_pair ((old_normal * old_count + q->second.first) / (old_count + 1),
- old_count + 1);
- }
- Assert (cell_to_normals_map.size() >= 1, ExcInternalError());
+ // in the same entry, store again the now averaged normal vector
+ // and the new count
+ cell_to_normals_map[q->second.second]
+ = std::make_pair ((old_normal * old_count + q->second.first) / (old_count + 1),
+ old_count + 1);
+ }
+ Assert (cell_to_normals_map.size() >= 1, ExcInternalError());
#ifdef DEBUG_NO_NORMAL_FLUX
- std::cout << " cell_to_normals_map:" << std::endl;
- for (typename CellToNormalsMap::const_iterator
- x = cell_to_normals_map.begin();
- x != cell_to_normals_map.end(); ++x)
- std::cout << " " << x->first << " -> ("
- << x->second.first << ',' << x->second.second << ')'
- << std::endl;
+ std::cout << " cell_to_normals_map:" << std::endl;
+ for (typename CellToNormalsMap::const_iterator
+ x = cell_to_normals_map.begin();
+ x != cell_to_normals_map.end(); ++x)
+ std::cout << " " << x->first << " -> ("
+ << x->second.first << ',' << x->second.second << ')'
+ << std::endl;
#endif
- // count the maximum number of contributions from each cell
- unsigned int max_n_contributions_per_cell = 1;
- for (typename CellToNormalsMap::const_iterator
- x = cell_to_normals_map.begin();
- x != cell_to_normals_map.end(); ++x)
+ // count the maximum number of contributions from each cell
+ unsigned int max_n_contributions_per_cell = 1;
+ for (typename CellToNormalsMap::const_iterator
+ x = cell_to_normals_map.begin();
+ x != cell_to_normals_map.end(); ++x)
max_n_contributions_per_cell
= std::max (max_n_contributions_per_cell,
x->second.second);
- // verify that each cell can have only contributed at most dim times,
- // since that is the maximum number of faces that come together at a
- // single place
- Assert (max_n_contributions_per_cell <= dim, ExcInternalError());
-
- switch (max_n_contributions_per_cell)
- {
- // first deal with the case that a number of cells all have
- // registered that they have a normal vector defined at the
- // location of a given vector dof, and that each of them have
- // encountered this vector dof exactly once while looping over all
- // their faces. as stated in the documentation, this is the case
- // where we want to simply average over all normal vectors
- //
- // the typical case is in 2d where multiple cells meet at one
- // vertex sitting on the boundary. same in 3d for a vertex that
- // is associated with only one of the boundary indicators passed
- // to this function
- case 1:
- {
-
- // compute the average normal vector from all the ones that have
- // the same set of dofs. we could add them up and divide them by
- // the number of additions, or simply normalize them right away
- // since we want them to have unit length anyway
- Tensor<1,dim> normal;
- for (typename CellToNormalsMap::const_iterator
- x = cell_to_normals_map.begin();
- x != cell_to_normals_map.end(); ++x)
- normal += x->second.first;
- normal /= normal.norm();
-
- // normalize again
- for (unsigned int d=0; d<dim; ++d)
- if (std::fabs(normal[d]) < 1e-13)
- normal[d] = 0;
- normal /= normal.norm();
-
- // then construct constraints from this:
- const internal::VectorDoFTuple<dim> &
- dof_indices = same_dof_range[0]->first;
- internal::add_constraint (dof_indices, normal,
- constraints);
+ // verify that each cell can have only contributed at most dim times,
+ // since that is the maximum number of faces that come together at a
+ // single place
+ Assert (max_n_contributions_per_cell <= dim, ExcInternalError());
- break;
- }
+ switch (max_n_contributions_per_cell)
+ {
+ // first deal with the case that a number of cells all have
+ // registered that they have a normal vector defined at the
+ // location of a given vector dof, and that each of them have
+ // encountered this vector dof exactly once while looping over all
+ // their faces. as stated in the documentation, this is the case
+ // where we want to simply average over all normal vectors
+ //
+ // the typical case is in 2d where multiple cells meet at one
+ // vertex sitting on the boundary. same in 3d for a vertex that
+ // is associated with only one of the boundary indicators passed
+ // to this function
+ case 1:
+ {
+ // compute the average normal vector from all the ones that have
+ // the same set of dofs. we could add them up and divide them by
+ // the number of additions, or simply normalize them right away
+ // since we want them to have unit length anyway
+ Tensor<1,dim> normal;
+ for (typename CellToNormalsMap::const_iterator
+ x = cell_to_normals_map.begin();
+ x != cell_to_normals_map.end(); ++x)
+ normal += x->second.first;
+ normal /= normal.norm();
+
+ // normalize again
+ for (unsigned int d=0; d<dim; ++d)
+ if (std::fabs(normal[d]) < 1e-13)
+ normal[d] = 0;
+ normal /= normal.norm();
+
+ // then construct constraints from this:
+ const internal::VectorDoFTuple<dim> &
+ dof_indices = same_dof_range[0]->first;
+ double normal_value = 0.;
+ const Vector<double> b_values = dof_vector_to_b_values[dof_indices];
+ for (unsigned int i=0; i<dim; ++i)
+ normal_value += b_values[i]*normal[i];
+ internal::add_constraint (dof_indices, normal,
+ constraints, normal_value);
+
+ break;
+ }
+ // this is the slightly more complicated case that a single cell has
+ // contributed with exactly DIM normal vectors to the same set of
+ // vector dofs. this is what happens in a corner in 2d and 3d (but
+ // not on an edge in 3d, where we have only 2, i.e. <DIM,
+ // contributions. Here we do not want to average the normal
+ // vectors. Since we have DIM contributions, let's assume (and
+ // verify) that they are in fact all linearly independent; in that
+ // case, all vector components are constrained and we need to solve
+ // a linear equation
+ case dim:
+ {
+ // assert that indeed only a single cell has contributed
+ Assert (cell_to_normals_map.size() == 1,
+ ExcInternalError());
- // this is the slightly more complicated case that a single cell has
- // contributed with exactly DIM normal vectors to the same set of
- // vector dofs. this is what happens in a corner in 2d and 3d (but
- // not on an edge in 3d, where we have only 2, i.e. <DIM,
- // contributions. Here we do not want to average the normal
- // vectors. Since we have DIM contributions, let's assume (and
- // verify) that they are in fact all linearly independent; in that
- // case, all vector components are constrained and we need to set
- // them to zero
- case dim:
+ // check linear independence by computing the determinant of the
+ // matrix created from all the normal vectors. if they are
+ // linearly independent, then the determinant is nonzero. if they
+ // are orthogonal, then the matrix is in fact equal to 1 (since
+ // they are all unit vectors); make sure the determinant is larger
+ // than 1e-3 to avoid cases where cells are degenerate
{
- // assert that indeed only a single cell has contributed
- Assert (cell_to_normals_map.size() == 1,
- ExcInternalError());
+ Tensor<2,dim> t;
+
+ typename DoFToNormalsMap::const_iterator x = same_dof_range[0];
+ for (unsigned int i=0; i<dim; ++i, ++x)
+ for (unsigned int j=0; j<dim; ++j)
+ t[i][j] = x->second.first[j];
+
+ Assert (std::fabs(determinant (t)) > 1e-3,
+ ExcMessage("Found a set of normal vectors that are nearly collinear."));
+ }
- // check linear independence by computing the determinant of the
- // matrix created from all the normal vectors. if they are
- // linearly independent, then the determinant is nonzero. if they
- // are orthogonal, then the matrix is in fact equal to 1 (since
- // they are all unit vectors); make sure the determinant is larger
- // than 1e-3 to avoid cases where cells are degenerate
+ // so all components of this vector dof are constrained. enter
+ // this into the constraint matrix
+ //
+ // ignore dofs already constrained
+ const internal::VectorDoFTuple<dim> &
+ dof_indices = same_dof_range[0]->first;
+ const Vector<double> b_values = dof_vector_to_b_values[dof_indices];
+ for (unsigned int i=0; i<dim; ++i)
+ if (!constraints.is_constrained(same_dof_range[0]->first.dof_indices[i])
+ &&
+ constraints.can_store_line(same_dof_range[0]->first.dof_indices[i]))
{
- Tensor<2,dim> t;
-
- typename DoFToNormalsMap::const_iterator x = same_dof_range[0];
- for (unsigned int i=0; i<dim; ++i, ++x)
- for (unsigned int j=0; j<dim; ++j)
- t[i][j] = x->second.first[j];
-
- Assert (std::fabs(determinant (t)) > 1e-3,
- ExcMessage("Found a set of normal vectors that are nearly collinear."));
+ const types::global_dof_index line
+ = dof_indices.dof_indices[i];
+ constraints.add_line (line);
+ if (std::fabs(b_values[i])
+ > std::numeric_limits<double>::epsilon())
+ constraints.set_inhomogeneity(line, b_values[i]);
+ // no add_entries here
}
- // so all components of this vector dof are constrained. enter
- // this into the constraint matrix
- //
- // ignore dofs already constrained
- for (unsigned int i=0; i<dim; ++i)
- if (!constraints.is_constrained (same_dof_range[0]
- ->first.dof_indices[i])
- &&
- constraints.can_store_line(
- same_dof_range[0]->first.dof_indices[i]))
- {
- constraints.add_line (same_dof_range[0]->first.dof_indices[i]);
- // no add_entries here
- }
-
break;
}
-
- // this is the case of an edge contribution in 3d, i.e. the vector
- // is constrained in two directions but not the third.
- default:
- {
- Assert (dim >= 3, ExcNotImplemented());
- Assert (max_n_contributions_per_cell == 2, ExcInternalError());
-
- // as described in the documentation, let us first collect what
- // each of the cells contributed at the current point. we use a
- // std::list instead of a std::set (which would be more natural)
- // because std::set requires that the stored elements are
- // comparable with operator<
- typedef
- std::map<typename DH<dim,spacedim>::active_cell_iterator, std::list<Tensor<1,dim> > >
+ // this is the case of an edge contribution in 3d, i.e. the vector
+ // is constrained in two directions but not the third.
+ default:
+ {
+ Assert (dim >= 3, ExcNotImplemented());
+ Assert (max_n_contributions_per_cell == 2, ExcInternalError());
+
+ // as described in the documentation, let us first collect what
+ // each of the cells contributed at the current point. we use a
+ // std::list instead of a std::set (which would be more natural)
+ // because std::set requires that the stored elements are
+ // comparable with operator<
+ typedef std::map<typename DH<dim,spacedim>::active_cell_iterator,
+ std::list<Tensor<1,dim> > >
CellContributions;
- CellContributions cell_contributions;
-
- for (typename DoFToNormalsMap::const_iterator
- q = same_dof_range[0];
- q != same_dof_range[1]; ++q)
- cell_contributions[q->second.second].push_back (q->second.first);
- Assert (cell_contributions.size() >= 1, ExcInternalError());
-
- // now for each cell that has contributed determine the number of
- // normal vectors it has contributed. we currently only implement
- // if this is dim-1 for all cells (if a single cell has
- // contributed dim, or if all adjacent cells have contributed 1
- // normal vector, this is already handled above).
- //
- // we only implement the case that all cells contribute
- // dim-1 because we assume that we are following an edge
- // of the domain (think: we are looking at a vertex
- // located on one of the edges of a refined cube where the
- // boundary indicators of the two adjacent faces of the
- // cube are both listed in the set of boundary indicators
- // passed to this function). in that case, all cells along
- // that edge of the domain are assumed to have contributed
- // dim-1 normal vectors. however, there are cases where
- // this assumption is not justified (see the lengthy
- // explanation in test no_flux_12.cc) and in those cases
- // we simply ignore the cell that contributes only
- // once. this is also discussed at length in the
- // documentation of this function.
- //
- // for each contributing cell compute the tangential vector that
- // remains unconstrained
- std::list<Tensor<1,dim> > tangential_vectors;
- for (typename CellContributions::const_iterator
- contribution = cell_contributions.begin();
- contribution != cell_contributions.end();
- ++contribution)
- {
+ CellContributions cell_contributions;
+
+ for (typename DoFToNormalsMap::const_iterator
+ q = same_dof_range[0];
+ q != same_dof_range[1]; ++q)
+ cell_contributions[q->second.second].push_back (q->second.first);
+ Assert (cell_contributions.size() >= 1, ExcInternalError());
+
+ // now for each cell that has contributed determine the number of
+ // normal vectors it has contributed. we currently only implement
+ // if this is dim-1 for all cells (if a single cell has
+ // contributed dim, or if all adjacent cells have contributed 1
+ // normal vector, this is already handled above).
+ //
+ // we only implement the case that all cells contribute
+ // dim-1 because we assume that we are following an edge
+ // of the domain (think: we are looking at a vertex
+ // located on one of the edges of a refined cube where the
+ // boundary indicators of the two adjacent faces of the
+ // cube are both listed in the set of boundary indicators
+ // passed to this function). in that case, all cells along
+ // that edge of the domain are assumed to have contributed
+ // dim-1 normal vectors. however, there are cases where
+ // this assumption is not justified (see the lengthy
+ // explanation in test no_flux_12.cc) and in those cases
+ // we simply ignore the cell that contributes only
+ // once. this is also discussed at length in the
+ // documentation of this function.
+ //
+ // for each contributing cell compute the tangential vector that
+ // remains unconstrained
+ std::list<Tensor<1,dim> > tangential_vectors;
+ for (typename CellContributions::const_iterator
+ contribution = cell_contributions.begin();
+ contribution != cell_contributions.end();
+ ++contribution)
+ {
#ifdef DEBUG_NO_NORMAL_FLUX
- std::cout << " Treating edge case with dim-1 contributions." << std::endl
- << " Looking at cell " << contribution->first
- << " which has contributed these normal vectors:"
- << std::endl;
- for (typename std::list<Tensor<1,dim> >::const_iterator
- t = contribution->second.begin();
- t != contribution->second.end();
- ++t)
- std::cout << " " << *t << std::endl;
+ std::cout << " Treating edge case with dim-1 contributions." << std::endl
+ << " Looking at cell " << contribution->first
+ << " which has contributed these normal vectors:"
+ << std::endl;
+ for (typename std::list<Tensor<1,dim> >::const_iterator
+ t = contribution->second.begin();
+ t != contribution->second.end();
+ ++t)
+ std::cout << " " << *t << std::endl;
#endif
- // as mentioned above, simply ignore cells that only
- // contribute once
- if (contribution->second.size() < dim-1)
- continue;
-
- Tensor<1,dim> normals[dim-1];
- {
- unsigned int index=0;
- for (typename std::list<Tensor<1,dim> >::const_iterator
- t = contribution->second.begin();
- t != contribution->second.end();
- ++t, ++index)
- normals[index] = *t;
- Assert (index == dim-1, ExcInternalError());
- }
-
- // calculate the tangent as the outer product of the normal
- // vectors. since these vectors do not need to be orthogonal
- // (think, for example, the case of the deal.II/no_flux_07
- // test: a sheared cube in 3d, with Q2 elements, where we have
- // constraints from the two normal vectors of two faces of the
- // sheared cube that are not perpendicular to each other), we
- // have to normalize the outer product
- Tensor<1,dim> tangent;
- switch (dim)
- {
- case 3:
- // take cross product between normals[0] and
- // normals[1]. write it in the current form (with [dim-2])
- // to make sure that compilers don't warn about
- // out-of-bounds accesses -- the warnings are bogus since
- // we get here only for dim==3, but at least one isn't
- // quite smart enough to notice this and warns when
- // compiling the function in 2d
- cross_product (tangent, normals[0], normals[dim-2]);
- break;
- default:
- Assert (false, ExcNotImplemented());
- }
-
- Assert (std::fabs (tangent.norm()) > 1e-12,
- ExcMessage("Two normal vectors from adjacent faces are almost "
- "parallel."));
- tangent /= tangent.norm();
-
- tangential_vectors.push_back (tangent);
- }
+ // as mentioned above, simply ignore cells that only
+ // contribute once
+ if (contribution->second.size() < dim-1)
+ continue;
+
+ Tensor<1,dim> normals[dim-1];
+ {
+ unsigned int index=0;
+ for (typename std::list<Tensor<1,dim> >::const_iterator
+ t = contribution->second.begin();
+ t != contribution->second.end();
+ ++t, ++index)
+ normals[index] = *t;
+ Assert (index == dim-1, ExcInternalError());
+ }
- // go through the list of tangents and make sure that they all
- // roughly point in the same direction as the first one (i.e. have
- // an angle less than 90 degrees); if they don't then flip their
- // sign
+ // calculate the tangent as the outer product of the normal
+ // vectors. since these vectors do not need to be orthogonal
+ // (think, for example, the case of the deal.II/no_flux_07
+ // test: a sheared cube in 3d, with Q2 elements, where we have
+ // constraints from the two normal vectors of two faces of the
+ // sheared cube that are not perpendicular to each other), we
+ // have to normalize the outer product
+ Tensor<1,dim> tangent;
+ switch (dim)
{
- const Tensor<1,dim> first_tangent = tangential_vectors.front();
- typename std::list<Tensor<1,dim> >::iterator
- t = tangential_vectors.begin();
- ++t;
- for (; t != tangential_vectors.end(); ++t)
- if (*t * first_tangent < 0)
- *t *= -1;
+ case 3:
+ // take cross product between normals[0] and
+ // normals[1]. write it in the current form (with [dim-2])
+ // to make sure that compilers don't warn about
+ // out-of-bounds accesses -- the warnings are bogus since
+ // we get here only for dim==3, but at least one isn't
+ // quite smart enough to notice this and warns when
+ // compiling the function in 2d
+ cross_product (tangent, normals[0], normals[dim-2]);
+ break;
+ default:
+ Assert (false, ExcNotImplemented());
}
- // now compute the average tangent and normalize it
- Tensor<1,dim> average_tangent;
- for (typename std::list<Tensor<1,dim> >::const_iterator
- t = tangential_vectors.begin();
- t != tangential_vectors.end();
- ++t)
- average_tangent += *t;
- average_tangent /= average_tangent.norm();
+ Assert (std::fabs (tangent.norm()) > 1e-12,
+ ExcMessage("Two normal vectors from adjacent faces are almost "
+ "parallel."));
+ tangent /= tangent.norm();
- // now all that is left is that we add the constraints that the
- // vector is parallel to the tangent
- const internal::VectorDoFTuple<dim> &
- dof_indices = same_dof_range[0]->first;
- internal::add_tangentiality_constraints (dof_indices,
- average_tangent,
- constraints);
+ tangential_vectors.push_back (tangent);
}
+
+ // go through the list of tangents and make sure that they all
+ // roughly point in the same direction as the first one (i.e. have
+ // an angle less than 90 degrees); if they don't then flip their
+ // sign
+ {
+ const Tensor<1,dim> first_tangent = tangential_vectors.front();
+ typename std::list<Tensor<1,dim> >::iterator
+ t = tangential_vectors.begin();
+ ++t;
+ for (; t != tangential_vectors.end(); ++t)
+ if (*t * first_tangent < 0)
+ *t *= -1;
}
+
+ // now compute the average tangent and normalize it
+ Tensor<1,dim> average_tangent;
+ for (typename std::list<Tensor<1,dim> >::const_iterator
+ t = tangential_vectors.begin();
+ t != tangential_vectors.end();
+ ++t)
+ average_tangent += *t;
+ average_tangent /= average_tangent.norm();
+
+ // now all that is left is that we add the constraints that the
+ // vector is parallel to the tangent
+ const internal::VectorDoFTuple<dim> &
+ dof_indices = same_dof_range[0]->first;
+ const Vector<double> b_values = dof_vector_to_b_values[dof_indices];
+ internal::add_tangentiality_constraints (dof_indices,
+ average_tangent,
+ constraints,
+ b_values);
+ }
}
+ }
}
const std::set<types::boundary_id> &boundary_ids,
ConstraintMatrix &constraints,
const Mapping<dim, spacedim> &mapping)
+ {
+ ZeroFunction<dim>zero_function(dim);
+ typename FunctionMap<spacedim>::type function_map;
+ std::set<types::boundary_id>::const_iterator it
+ = boundary_ids.begin();
+ for (;it != boundary_ids.end(); ++it)
+ function_map[*it] = &zero_function;
+ compute_nonzero_tangential_flux_constraints(dof_handler,
+ first_vector_component,
+ boundary_ids,
+ function_map,
+ constraints,
+ mapping);
+ }
+
+ template <int dim, template <int, int> class DH, int spacedim>
+ void
+ compute_nonzero_tangential_flux_constraints (const DH<dim,spacedim> &dof_handler,
+ const unsigned int first_vector_component,
+ const std::set<types::boundary_id> &boundary_ids,
+ typename FunctionMap<spacedim>::type &function_map,
+ ConstraintMatrix &constraints,
+ const Mapping<dim, spacedim> &mapping)
{
ConstraintMatrix no_normal_flux_constraints(constraints.get_local_lines());
- compute_no_normal_flux_constraints (dof_handler,
- first_vector_component,
- boundary_ids,
- no_normal_flux_constraints,
- mapping);
+ compute_nonzero_normal_flux_constraints (dof_handler,
+ first_vector_component,
+ boundary_ids,
+ function_map,
+ no_normal_flux_constraints,
+ mapping);
+
+ hp::FECollection<dim,spacedim> fe_collection (dof_handler.get_fe());
+ hp::MappingCollection<dim,spacedim> mapping_collection;
+ for (unsigned int i=0; i<fe_collection.size(); ++i)
+ mapping_collection.push_back (mapping);
+
+ // now also create a quadrature collection for the faces of a cell. fill
+ // it with a quadrature formula with the support points on faces for each
+ // FE
+ hp::QCollection<dim-1> face_quadrature_collection;
+ for (unsigned int i=0; i<fe_collection.size(); ++i)
+ {
+ const std::vector<Point<dim-1> > &
+ unit_support_points = fe_collection[i].get_unit_face_support_points();
+
+ Assert (unit_support_points.size() == fe_collection[i].dofs_per_face,
+ ExcInternalError());
+
+ face_quadrature_collection.push_back (Quadrature<dim-1> (unit_support_points));
+ }
+
+ // now create the object with which we will generate the normal vectors
+ hp::FEFaceValues<dim,spacedim> x_fe_face_values (mapping_collection,
+ fe_collection,
+ face_quadrature_collection,
+ update_q_points |
+ update_normal_vectors);
// Extract a list that collects all vector components that belong to the
// same node (scalar basis function). When creating that list, we use an
std::set<std_cxx1x::array<types::global_dof_index,dim>, PointComparator<dim> > vector_dofs;
std::vector<types::global_dof_index> face_dofs;
+ std::map<std_cxx1x::array<types::global_dof_index,dim>, Vector<double> >
+ dof_vector_to_b_values;
+
+ std::set<types::boundary_id>::iterator b_id;
std::vector<std_cxx1x::array<types::global_dof_index,dim> > cell_vector_dofs;
for (typename DH<dim,spacedim>::active_cell_iterator cell =
dof_handler.begin_active(); cell != dof_handler.end(); ++cell)
if (!cell->is_artificial())
for (unsigned int face_no=0; face_no < GeometryInfo<dim>::faces_per_cell;
++face_no)
- if (boundary_ids.find(cell->face(face_no)->boundary_indicator())
+ if ((b_id=boundary_ids.find(cell->face(face_no)->boundary_indicator()))
!= boundary_ids.end())
{
const FiniteElement<dim> &fe = cell->get_fe();
face_dofs.resize (fe.dofs_per_face);
face->get_dof_indices (face_dofs, cell->active_fe_index());
+ x_fe_face_values.reinit (cell, face_no);
+ const FEFaceValues<dim> &fe_values = x_fe_face_values.get_present_fe_values();
+
+ std::map<types::global_dof_index, double> dof_to_b_value;
+
unsigned int n_scalar_indices = 0;
cell_vector_dofs.resize(fe.dofs_per_face);
for (unsigned int i=0; i<fe.dofs_per_face; ++i)
+ {
if (fe.face_system_to_component_index(i).first >= first_vector_component &&
fe.face_system_to_component_index(i).first < first_vector_component + dim)
- {
- n_scalar_indices =
- std::max(n_scalar_indices,
- fe.face_system_to_component_index(i).second+1);
- cell_vector_dofs[fe.face_system_to_component_index(i).second]
- [fe.face_system_to_component_index(i).first-first_vector_component]
- = face_dofs[i];
- }
+ {
+ const unsigned int component
+ = fe.face_system_to_component_index(i).first
+ -first_vector_component;
+ n_scalar_indices =
+ std::max(n_scalar_indices,
+ fe.face_system_to_component_index(i).second+1);
+ cell_vector_dofs[fe.face_system_to_component_index(i).second]
+ [component]
+ = face_dofs[i];
+
+ const Point<dim> point
+ = fe_values.quadrature_point(i);
+ const double b_value
+ = function_map[*b_id]->value(point, component);
+ dof_to_b_value.insert
+ (std::make_pair(face_dofs[i], b_value));
+ }
+ }
// now we identified the vector indices on the cell, so next
// insert them into the set (it would be expensive to directly
// insert incomplete points into the set)
for (unsigned int i=0; i<n_scalar_indices; ++i)
+ {
vector_dofs.insert(cell_vector_dofs[i]);
+ Vector<double> b_values(dim);
+ for (unsigned int j=0; j<dim; ++j)
+ b_values[j]=dof_to_b_value[cell_vector_dofs[i][j]];
+ dof_vector_to_b_values.insert
+ (std::make_pair(cell_vector_dofs[i], b_values));
+ }
+
}
// iterate over the list of all vector components we found and see if we
// if more than one no-flux constraint is present, we need to
// constrain all vector degrees of freedom (we are in a corner
// where several faces meet and to get a continuous FE solution we
- // need to set all conditions to zero).
+ // need to set all conditions corresponding to the boundary function.).
if (n_constraints > 1)
{
+ const Vector<double> b_value = dof_vector_to_b_values[*it];
for (unsigned int d=0; d<dim; ++d)
+ {
constraints.add_line((*it)[d]);
+ constraints.set_inhomogeneity((*it)[d], b_value(d));
+ }
continue;
}
Assert (index != -1, ExcInternalError());
normal[index] = (*constrained)[c].second;
}
+ Vector<double> boundary_value = dof_vector_to_b_values[*it];
for (unsigned int d=0; d<dim; ++d)
{
if (is_constrained[d])
if (std::abs(normal[d]) > 1e-13)
constraints.add_entry(new_index, (*it)[constrained_index],
-normal[d]);
+ constraints.set_inhomogeneity(new_index, boundary_value[d]);
}
}
}
projects / dealii-svn.git / commitdiff