Reference documentation for deal.II version 9.4.0

#include <deal.II/dofs/dof_accessor.h>
Public Types  
using  AccessorData = DoFHandler< dimension_, space_dimension_ > 
using  BaseClass = DoFAccessor< dimension_, dimension_, space_dimension_, level_dof_access > 
using  Container = DoFHandler< dimension_, space_dimension_ > 
using  face_iterator = TriaIterator< DoFAccessor< dimension_  1, dimension_, space_dimension_, level_dof_access > > 
Public Member Functions  
TriaIterator< DoFCellAccessor< dimension_, space_dimension_, level_dof_access > >  parent () const 
void  set_dof_indices (const std::vector< types::global_dof_index > &dof_indices) 
void  set_mg_dof_indices (const std::vector< types::global_dof_index > &dof_indices) 
void  update_cell_dof_indices_cache () const 
const DoFHandler< dim, spacedim > &  get_dof_handler () const 
void  copy_from (const DoFAccessor< structdim, dim, spacedim, level_dof_access2 > &a) 
void  copy_from (const TriaAccessorBase< structdim, dim, spacedim > &da) 
bool  operator== (const DoFAccessor< structdim2, dim2, spacedim2, level_dof_access2 > &) const 
bool  operator!= (const DoFAccessor< structdim2, dim2, spacedim2, level_dof_access2 > &) const 
Constructors and initialization  
DoFCellAccessor (const Triangulation< dimension_, space_dimension_ > *tria, const int level, const int index, const AccessorData *local_data)  
template<int structdim2, int dim2, int spacedim2>  
DoFCellAccessor (const InvalidAccessor< structdim2, dim2, spacedim2 > &)  
template<int structdim2, int dim2, int spacedim2, bool level_dof_access2>  
DoFCellAccessor (const DoFAccessor< structdim2, dim2, spacedim2, level_dof_access2 > &)  
DoFCellAccessor (const DoFCellAccessor< dimension_, space_dimension_, level_dof_access > &)=default  
DoFCellAccessor (DoFCellAccessor< dimension_, space_dimension_, level_dof_access > &&)=default  
~DoFCellAccessor ()=default  
DoFCellAccessor< dimension_, space_dimension_, level_dof_access > &  operator= (const DoFCellAccessor< dimension_, space_dimension_, level_dof_access > &da)=delete 
DoFCellAccessor< dimension_, space_dimension_, level_dof_access > &  operator= (DoFCellAccessor< dimension_, space_dimension_, level_dof_access > &&)=default 
Accessing subobjects and neighbors  
TriaIterator< DoFCellAccessor< dimension_, space_dimension_, level_dof_access > >  neighbor (const unsigned int i) const 
TriaIterator< DoFCellAccessor< dimension_, space_dimension_, level_dof_access > >  periodic_neighbor (const unsigned int i) const 
TriaIterator< DoFCellAccessor< dimension_, space_dimension_, level_dof_access > >  neighbor_or_periodic_neighbor (const unsigned int i) const 
TriaIterator< DoFCellAccessor< dimension_, space_dimension_, level_dof_access > >  child (const unsigned int i) const 
boost::container::small_vector< TriaIterator< DoFCellAccessor< dimension_, space_dimension_, level_dof_access > >, GeometryInfo< dimension_ >::max_children_per_cell >  child_iterators () const 
face_iterator  face (const unsigned int i) const 
boost::container::small_vector< face_iterator, GeometryInfo< dimension_ >::faces_per_cell >  face_iterators () const 
TriaIterator< DoFCellAccessor< dimension_, space_dimension_, level_dof_access > >  neighbor_child_on_subface (const unsigned int face_no, const unsigned int subface_no) const 
TriaIterator< DoFCellAccessor< dimension_, space_dimension_, level_dof_access > >  periodic_neighbor_child_on_subface (const unsigned int face_no, const unsigned int subface_no) const 
Extracting values from global vectors  
template<class InputVector , typename number >  
void  get_dof_values (const InputVector &values, Vector< number > &local_values) const 
template<class InputVector , typename ForwardIterator >  
void  get_dof_values (const InputVector &values, ForwardIterator local_values_begin, ForwardIterator local_values_end) const 
template<class InputVector , typename ForwardIterator >  
void  get_dof_values (const AffineConstraints< typename InputVector::value_type > &constraints, const InputVector &values, ForwardIterator local_values_begin, ForwardIterator local_values_end) const 
template<class OutputVector , typename number >  
void  set_dof_values (const Vector< number > &local_values, OutputVector &values) const 
template<class InputVector , typename number >  
void  get_interpolated_dof_values (const InputVector &values, Vector< number > &interpolated_values, const unsigned int fe_index=DoFHandler< dimension_, space_dimension_ >::invalid_fe_index) const 
template<class OutputVector , typename number >  
void  set_dof_values_by_interpolation (const Vector< number > &local_values, OutputVector &values, const unsigned int fe_index=DoFHandler< dimension_, space_dimension_ >::invalid_fe_index, const bool perform_check=false) const 
template<class OutputVector , typename number >  
void  distribute_local_to_global_by_interpolation (const Vector< number > &local_values, OutputVector &values, const unsigned int fe_index=DoFHandler< dimension_, space_dimension_ >::invalid_fe_index) const 
template<typename number , typename OutputVector >  
void  distribute_local_to_global (const Vector< number > &local_source, OutputVector &global_destination) const 
template<typename ForwardIterator , typename OutputVector >  
void  distribute_local_to_global (ForwardIterator local_source_begin, ForwardIterator local_source_end, OutputVector &global_destination) const 
template<typename ForwardIterator , typename OutputVector >  
void  distribute_local_to_global (const AffineConstraints< typename OutputVector::value_type > &constraints, ForwardIterator local_source_begin, ForwardIterator local_source_end, OutputVector &global_destination) const 
template<typename number , typename OutputMatrix >  
void  distribute_local_to_global (const FullMatrix< number > &local_source, OutputMatrix &global_destination) const 
template<typename number , typename OutputMatrix , typename OutputVector >  
void  distribute_local_to_global (const FullMatrix< number > &local_matrix, const Vector< number > &local_vector, OutputMatrix &global_matrix, OutputVector &global_vector) const 
Accessing the DoF indices of this object  
void  get_active_or_mg_dof_indices (std::vector< types::global_dof_index > &dof_indices) const 
void  get_dof_indices (std::vector< types::global_dof_index > &dof_indices) const 
void  get_mg_dof_indices (std::vector< types::global_dof_index > &dof_indices) const 
Accessing the finite element associated with this object  
const FiniteElement< dimension_, space_dimension_ > &  get_fe () const 
unsigned int  active_fe_index () const 
void  set_active_fe_index (const unsigned int i) const 
Dealing with refinement indicators  
const FiniteElement< dimension_, space_dimension_ > &  get_future_fe () const 
unsigned int  future_fe_index () const 
void  set_future_fe_index (const unsigned int i) const 
bool  future_fe_index_set () const 
void  clear_future_fe_index () const 
Accessing subobjects  
typename::internal::DoFHandlerImplementation::Iterators< dim, spacedim, level_dof_access >::line_iterator  line (const unsigned int i) const 
typename::internal::DoFHandlerImplementation::Iterators< dim, spacedim, level_dof_access >::quad_iterator  quad (const unsigned int i) const 
Accessing the DoF indices of this object  
void  get_dof_indices (std::vector< types::global_dof_index > &dof_indices, const unsigned int fe_index=DoFHandler< dim, spacedim >::invalid_fe_index) const 
void  get_mg_dof_indices (const int level, std::vector< types::global_dof_index > &dof_indices, const unsigned int fe_index=DoFHandler< dim, spacedim >::invalid_fe_index) const 
void  set_mg_dof_indices (const int level, const std::vector< types::global_dof_index > &dof_indices, const unsigned int fe_index=DoFHandler< dim, spacedim >::invalid_fe_index) 
types::global_dof_index  vertex_dof_index (const unsigned int vertex, const unsigned int i, const unsigned int fe_index=DoFHandler< dim, spacedim >::invalid_fe_index) const 
types::global_dof_index  mg_vertex_dof_index (const int level, const unsigned int vertex, const unsigned int i, const unsigned int fe_index=DoFHandler< dim, spacedim >::invalid_fe_index) const 
types::global_dof_index  dof_index (const unsigned int i, const unsigned int fe_index=DoFHandler< dim, spacedim >::invalid_fe_index) const 
types::global_dof_index  mg_dof_index (const int level, const unsigned int i) const 
Accessing the finite element associated with this object  
unsigned int  n_active_fe_indices () const 
unsigned int  nth_active_fe_index (const unsigned int n) const 
std::set< unsigned int >  get_active_fe_indices () const 
bool  fe_index_is_active (const unsigned int fe_index) const 
const FiniteElement< dim, spacedim > &  get_fe (const unsigned int fe_index) const 
Static Public Member Functions  
static bool  is_level_cell () 
static ::ExceptionBase &  ExcInvalidObject () 
static ::ExceptionBase &  ExcVectorNotEmpty () 
static ::ExceptionBase &  ExcVectorDoesNotMatch () 
static ::ExceptionBase &  ExcMatrixDoesNotMatch () 
static ::ExceptionBase &  ExcNotActive () 
static ::ExceptionBase &  ExcCantCompareIterators () 
Static Public Attributes  
static const unsigned int  dim = dimension_ 
static const unsigned int  spacedim = space_dimension_ 
static constexpr unsigned int  dimension 
static constexpr unsigned int  space_dimension 
Protected Member Functions  
void  set_dof_handler (DoFHandler< dim, spacedim > *dh) 
void  set_dof_index (const unsigned int i, const types::global_dof_index index, const unsigned int fe_index=DoFHandler< dim, spacedim >::invalid_fe_index) const 
void  set_mg_dof_index (const int level, const unsigned int i, const types::global_dof_index index) const 
void  set_mg_vertex_dof_index (const int level, const unsigned int vertex, const unsigned int i, const types::global_dof_index index, const unsigned int fe_index=DoFHandler< dim, spacedim >::invalid_fe_index) const 
Protected Attributes  
DoFHandler< dim, spacedim > *  dof_handler 
Friends  
template<int , int >  
class  DoFHandler 
struct  ::internal::DoFCellAccessorImplementation::Implementation 
Grant access to the degrees of freedom on a cell.
Note that since for the class we derive from, i.e. DoFAccessor<dim>
, the two template parameters are equal, the base class is actually derived from CellAccessor, which makes the functions of this class available to the DoFCellAccessor class as well.
Definition at line 1327 of file dof_accessor.h.
using DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::AccessorData = DoFHandler<dimension_, space_dimension_> 
Data type passed by the iterator class.
Definition at line 1347 of file dof_accessor.h.
using DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::BaseClass = DoFAccessor<dimension_, dimension_, space_dimension_, level_dof_access> 
Declare an alias to the base class to make accessing some of the exception classes simpler.
Definition at line 1353 of file dof_accessor.h.
using DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::Container = DoFHandler<dimension_, space_dimension_> 
Define the type of the container this is part of.
Definition at line 1359 of file dof_accessor.h.
using DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::face_iterator = TriaIterator<DoFAccessor<dimension_  1, dimension_, space_dimension_, level_dof_access> > 
A type for an iterator over the faces of a cell. This is what the face() function returns.
Definition at line 1365 of file dof_accessor.h.
DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::DoFCellAccessor  (  const Triangulation< dimension_, space_dimension_ > *  tria, 
const int  level,  
const int  index,  
const AccessorData *  local_data  
) 
Constructor
DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::DoFCellAccessor  (  const InvalidAccessor< structdim2, dim2, spacedim2 > &  ) 
Conversion constructor. This constructor exists to make certain constructs simpler to write in dimension independent code. For example, it allows assigning a face iterator to a line iterator, an operation that is useful in 2d but doesn't make any sense in 3d. The constructor here exists for the purpose of making the code conform to C++ but it will unconditionally abort; in other words, assigning a face iterator to a line iterator is better put into an ifstatement that checks that the dimension is two, and assign to a quad iterator in 3d (an operator that, without this constructor would be illegal if we happen to compile for 2d).

explicit 
Another conversion operator between objects that don't make sense, just like the previous one.

default 
Copy constructor.

default 
Move constructor.

default 
Destructor

delete 
Copy operator. These operators are usually used in a context like iterator a,b; *a=*b;
. Presumably, the intent here is to copy the object pointed to by b
to the object pointed to by a
. However, the result of dereferencing an iterator is not an object but an accessor; consequently, this operation is not useful for iterators on DoF handler objects. Consequently, this operator is declared as deleted and can not be used.

default 
Move assignment operator.
TriaIterator< DoFCellAccessor< dimension_, space_dimension_, level_dof_access > > DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::parent  (  )  const 
Return the parent of this cell as a DoF cell iterator. If the parent does not exist (i.e., if the object is at the coarsest level of the mesh hierarchy), an exception is generated.
This function is needed since the parent function of the base class CellAccessor returns a triangulation cell accessor without access to the DoF data.
TriaIterator< DoFCellAccessor< dimension_, space_dimension_, level_dof_access > > DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::neighbor  (  const unsigned int  i  )  const 
Return the ith
neighbor as a DoF cell iterator. This function is needed since the neighbor function of the base class returns a cell accessor without access to the DoF data.

inline 
Return the ith
periodic neighbor as a DoF cell iterator. This function is needed since the neighbor function of the base class returns a cell accessor without access to the DoF data.
Definition at line 172 of file dof_accessor.cc.

inline 
Return the ith
neighbor or periodic neighbor as a DoF cell iterator. This function is needed since the neighbor function of the base class returns a cell accessor without access to the DoF data.
Definition at line 185 of file dof_accessor.cc.
TriaIterator< DoFCellAccessor< dimension_, space_dimension_, level_dof_access > > DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::child  (  const unsigned int  i  )  const 
Return the ith
child as a DoF cell iterator. This function is needed since the child function of the base class returns a cell accessor without access to the DoF data.
boost::container::small_vector< TriaIterator< DoFCellAccessor< dimension_, space_dimension_, level_dof_access > >, GeometryInfo< dimension_ >::max_children_per_cell > DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::child_iterators  (  )  const 
Return an array of iterators to all children of this cell.
face_iterator DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::face  (  const unsigned int  i  )  const 
Return an iterator to the ith
face of this cell.
This function returns a DoFAccessor with structdim == 0
in 1D, a DoFAccessor::line in 2D, and a DoFAccessor::quad in 3d.
boost::container::small_vector< face_iterator, GeometryInfo< dimension_ >::faces_per_cell > DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::face_iterators  (  )  const 
Return an array of iterators to all faces of this cell.
TriaIterator< DoFCellAccessor< dim, spacedim, lda > > DoFCellAccessor< dim, spacedim, lda >::neighbor_child_on_subface  (  const unsigned int  face_no, 
const unsigned int  subface_no  
)  const 
Return the result of the neighbor_child_on_subface
function of the base class, but convert it so that one can also access the DoF data (the function in the base class only returns an iterator with access to the triangulation data).
Definition at line 143 of file dof_accessor.cc.
TriaIterator< DoFCellAccessor< dim, spacedim, lda > > DoFCellAccessor< dim, spacedim, lda >::periodic_neighbor_child_on_subface  (  const unsigned int  face_no, 
const unsigned int  subface_no  
)  const 
Return the result of the periodic_neighbor_child_on_subface
function of the base class, but convert it so that one can also access the DoF data (the function in the base class only returns an iterator with access to the triangulation data).
Definition at line 157 of file dof_accessor.cc.
void DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::get_dof_values  (  const InputVector &  values, 
Vector< number > &  local_values  
)  const 
Collect the values of the given vector restricted to the dofs of this cell in the standard ordering: dofs on vertex 0, dofs on vertex 1, etc, dofs on line 0, dofs on line 1, etc, dofs on quad 0, etc. In other words, this function implements a gather operation.
The vector has to have the right size before being passed to this function. This function is only callable for active cells.
The input vector may be either a Vector<float>
, Vector<double>, or a BlockVector<double>, or a PETSc or Trilinos vector if deal.II is compiled to support these libraries. It is in the responsibility of the caller to assure that the types of the numbers stored in input and output vectors are compatible and with similar accuracy.
void DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::get_dof_values  (  const InputVector &  values, 
ForwardIterator  local_values_begin,  
ForwardIterator  local_values_end  
)  const 
Collect the values of the given vector restricted to the dofs of this cell in the standard ordering: dofs on vertex 0, dofs on vertex 1, etc, dofs on line 0, dofs on line 1, etc, dofs on quad 0, etc. In other words, this function implements a gather operation.
The vector has to have the right size before being passed to this function. This function is only callable for active cells.
The input vector may be either a Vector<float>
, Vector<double>, or a BlockVector<double>, or a PETSc or Trilinos vector if deal.II is compiled to support these libraries. It is in the responsibility of the caller to assure that the types of the numbers stored in input and output vectors are compatible and with similar accuracy.
void DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::get_dof_values  (  const AffineConstraints< typename InputVector::value_type > &  constraints, 
const InputVector &  values,  
ForwardIterator  local_values_begin,  
ForwardIterator  local_values_end  
)  const 
Collect the values of the given vector restricted to the dofs of this cell in the standard ordering: dofs on vertex 0, dofs on vertex 1, etc, dofs on line 0, dofs on line 1, etc, dofs on quad 0, etc. In other words, this function implements a gather operation.
The vector has to have the right size before being passed to this function. This function is only callable for active cells.
The input vector may be either a Vector<float>
, Vector<double>, or a BlockVector<double>, or a PETSc or Trilinos vector if deal.II is compiled to support these libraries. It is in the responsibility of the caller to assure that the types of the numbers stored in input and output vectors are compatible and with similar accuracy. The AffineConstraints object passed as an argument to this function makes sure that constraints are correctly distributed when the dof values are calculated.
void DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::set_dof_values  (  const Vector< number > &  local_values, 
OutputVector &  values  
)  const 
This function is the counterpart to get_dof_values(): it takes a vector of values for the degrees of freedom of the cell pointed to by this iterator and writes these values into the global data vector values
. In other words, this function implements a scatter operation. This function is only callable for active cells.
Note that for continuous finite elements, calling this function affects the dof values on neighboring cells as well. It may also violate continuity requirements for hanging nodes, if neighboring cells are less refined than the present one. These requirements are not taken care of and must be enforced by the user afterwards.
The vector has to have the right size before being passed to this function.
The output vector may be either a Vector<float>, Vector<double>, or a BlockVector<double>, or a PETSc vector if deal.II is compiled to support these libraries. It is in the responsibility of the caller to assure that the types of the numbers stored in input and output vectors are compatible and with similar accuracy.
void DoFCellAccessor< dim, spacedim, lda >::get_interpolated_dof_values  (  const InputVector &  values, 
Vector< number > &  interpolated_values,  
const unsigned int  fe_index = DoFHandler<dimension_, space_dimension_>::invalid_fe_index 

)  const 
Return the interpolation of the given finite element function to the present cell. In the simplest case, the cell is a terminal one, i.e., it has no children; then, the returned value is the vector of nodal values on that cell. You could as well get the desired values through the get_dof_values
function. In the other case, when the cell has children, we use the restriction matrices provided by the finite element class to compute the interpolation from the children to the present cell.
If the cell is part of a DoFHandler with hpcapabilities, cells only have an associated finite element space if they are active. However, this function is supposed to also provide information on inactive cells with children. Consequently, it carries a third argument that can be used in the hpcontext that denotes the finite element space we are supposed to interpolate onto. If the cell is active, this function then obtains the finite element function from the values
vector on this cell and interpolates it onto the space described by the fe_index
th element of the hp::FECollection associated with the DoFHandler of which this cell is a part of. If the cell is not active, then we first perform this interpolation on all of its terminal children and then interpolate this function down to the cell requested keeping the function space the same.
It is assumed that both input vectors already have the right size beforehand.
Definition at line 48 of file dof_accessor_get.cc.
void DoFCellAccessor< dim, spacedim, lda >::set_dof_values_by_interpolation  (  const Vector< number > &  local_values, 
OutputVector &  values,  
const unsigned int  fe_index = DoFHandler<dimension_, space_dimension_>::invalid_fe_index , 

const bool  perform_check = false 

)  const 
This function is the counterpart to get_interpolated_dof_values(): you specify the dof values on a cell and these are interpolated to the children of the present cell and set on the terminal cells.
In principle, it works as follows: if the cell pointed to by this object is terminal (i.e., has no children), then the dof values are set in the global data vector by calling the set_dof_values() function; otherwise, the values are prolonged to each of the children and this function is called for each of them.
Using the get_interpolated_dof_values() and this function, you can compute the interpolation of a finite element function to a coarser grid by first getting the interpolated solution on a cell of the coarse grid and afterwards redistributing it using this function.
Note that for continuous finite elements, calling this function affects the dof values on neighboring cells as well. It may also violate continuity requirements for hanging nodes, if neighboring cells are less refined than the present one, or if their children are less refined than the children of this cell. These requirements are not taken care of and must be enforced by the user afterward.
If the cell is part of a DoFHandler with hpcapabilities, cells only have an associated finite element space if they are active. However, this function is supposed to also work on inactive cells with children. Consequently, it carries a third argument that can be used in the hp context that denotes the finite element space we are supposed to interpret the input vector of this function in. If the cell is active, this function then interpolates the input vector interpreted as an element of the space described by the fe_index
th element of the hp::FECollection associated with the DoFHandler of which this cell is a part of, and interpolates it into the space that is associated with this cell. On the other hand, if the cell is not active, then we first perform this interpolation from this cell to its children using the given fe_index
until we end up on an active cell, at which point we follow the procedure outlined at the beginning of the paragraph.
It is assumed that both vectors already have the right size beforehand. This function relies on the existence of a natural interpolation property of finite element spaces of a cell to its children, denoted by the prolongation matrices of finite element classes. For some elements, the spaces on coarse and fine grids are not nested, in which case the interpolation to a child is not the identity; refer to the documentation of the respective finite element class for a description of what the prolongation matrices represent in this case.
perform_check
, you can enable a check that the previous value and the one to be set here are at least roughly the same. In practice, they might be slightly different because they are computed in a way that theoretically ensures that they are the same, but in practice they are only equal up to roundoff.Definition at line 273 of file dof_accessor_set.cc.
void DoFCellAccessor< dim, spacedim, lda >::distribute_local_to_global_by_interpolation  (  const Vector< number > &  local_values, 
OutputVector &  values,  
const unsigned int  fe_index = DoFHandler<dimension_, space_dimension_>::invalid_fe_index 

)  const 
Similar to set_dof_values_by_interpolation() with the difference that values are added into the vector.
Definition at line 295 of file dof_accessor_set.cc.
void DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::distribute_local_to_global  (  const Vector< number > &  local_source, 
OutputVector &  global_destination  
)  const 
Distribute a local (cell based) vector to a global one by mapping the local numbering of the degrees of freedom to the global one and entering the local values into the global vector. In other words, this function implements a scatter operation.
The elements are added to the existing elements in the global vector, rather than just set, since this is usually what one wants. You may also want to take a look at the AffineConstraints::distribute_local_to_global() function if you need to deal with constraints.
void DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::distribute_local_to_global  (  ForwardIterator  local_source_begin, 
ForwardIterator  local_source_end,  
OutputVector &  global_destination  
)  const 
Distribute a local (cell based) vector in iterator format to a global one by mapping the local numbering of the degrees of freedom to the global one and entering the local values into the global vector. In other words, this function implements a scatter operation.
The elements are added to the existing elements in the global vector, rather than just set, since this is usually what one wants. You may also want to take a look at the AffineConstraints::distribute_local_to_global() function if you need to deal with constraints.
void DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::distribute_local_to_global  (  const AffineConstraints< typename OutputVector::value_type > &  constraints, 
ForwardIterator  local_source_begin,  
ForwardIterator  local_source_end,  
OutputVector &  global_destination  
)  const 
Distribute a local (cell based) vector in iterator format to a global one by mapping the local numbering of the degrees of freedom to the global one and entering the local values into the global vector. In other words, this function implements a scatter operation.
The elements are added up to the elements in the global vector, rather than just set, since this is usually what one wants. Moreover, the AffineConstraints object passed to this function makes sure that also constraints are eliminated in this process.
void DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::distribute_local_to_global  (  const FullMatrix< number > &  local_source, 
OutputMatrix &  global_destination  
)  const 
This function does much the same as the distribute_local_to_global(Vector,Vector)
function, but operates on matrices instead of vectors. If the matrix type is a sparse matrix then it is supposed to have nonzero entry slots where required.
void DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::distribute_local_to_global  (  const FullMatrix< number > &  local_matrix, 
const Vector< number > &  local_vector,  
OutputMatrix &  global_matrix,  
OutputVector &  global_vector  
)  const 
This function does what the two distribute_local_to_global
functions with vector and matrix argument do, but all at once.
void DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::get_active_or_mg_dof_indices  (  std::vector< types::global_dof_index > &  dof_indices  )  const 
Obtain the global indices of the local degrees of freedom on this cell.
If this object accesses a level cell (indicated by the third template argument or is_level_cell), then return the result of get_mg_dof_indices(), else return get_dof_indices().
You will get a level_cell_iterator when calling begin_mg() and a normal one otherwise.
Examples for this use are in the implementation of DoFRenumbering.
void DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::get_dof_indices  (  std::vector< types::global_dof_index > &  dof_indices  )  const 
Return the global indices of the degrees of freedom located on this object in the standard ordering defined by the finite element (i.e., dofs on vertex 0, dofs on vertex 1, etc, dofs on line 0, dofs on line 1, etc, dofs on quad 0, etc.) This function is only available on active objects (see this glossary entry).
[out]  dof_indices  The vector into which the indices will be written. It has to have the right size (namely, fe.n_dofs_per_cell() , fe.dofs_per_face , or fe.dofs_per_line , depending on which kind of object this function is called) before being passed to this function. 
This function reimplements the same function in the base class. In contrast to the function in the base class, we do not need the fe_index
here because there is always a unique finite element index on cells.
This is a function which requires that the cell is active.
Also see get_active_or_mg_dof_indices().
local_dof_indices
by convention. The name is not meant to indicate the local numbers of degrees of freedom (which are always between zero and fe.n_dofs_per_cell()
) but instead that the returned values are the global indices of those degrees of freedom that are located locally on the current cell. void DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::get_mg_dof_indices  (  std::vector< types::global_dof_index > &  dof_indices  )  const 
Retrieve the global indices of the degrees of freedom on this cell in the level vector associated to the level of the cell.
const FiniteElement< dimension_, space_dimension_ > & DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::get_fe  (  )  const 
Return the finite element that is used on the cell pointed to by this iterator. For DoFHandler objects without hpcapabilities, this is of course always the same element, independent of the cell we are presently on, but for hpDoFHandler objects this may change from cell to cell.
unsigned int DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::active_fe_index  (  )  const 
Return the index inside the hp::FECollection of the FiniteElement used for this cell. This function is only useful if the DoFHandler object associated with the current cell has hpcapabilities enabled.
active_fe_index
information is only exchanged from locally owned cells on one processor to other processors where they may be ghost cells, during the call to DoFHandler::set_fe() and DoFHandler::distribute_dofs(). Be aware that if you call set_active_fe_index() on a cell after calling one of these functions, then this information will not be propagated to other processors who may have this cell as a ghost cell. See the documentation of DoFHandler for more information. void DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::set_active_fe_index  (  const unsigned int  i  )  const 
Set the index of the FiniteElement used for this cell. This determines which element in an hp::FECollection to use. This function is only useful if the DoF handler object associated with the current cell has hp capabilities enabled.
active_fe_index
information is only exchanged from locally owned cells on one processor to other processors where they may be ghost cells, during the call to DoFHandler::set_fe() and DoFHandler::distribute_dofs(). Be aware that if you call set_active_fe_index() on a cell after calling one of these functions, then this information will not be propagated to other processors who may have this cell as a ghost cell. See the documentation of DoFHandler for more information. void DoFCellAccessor< dim, spacedim, lda >::set_dof_indices  (  const std::vector< types::global_dof_index > &  dof_indices  ) 
Set the DoF indices of this cell to the given values. This function bypasses the DoF cache, if one exists for the given DoF handler class.
Definition at line 124 of file dof_accessor.cc.
void DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::set_mg_dof_indices  (  const std::vector< types::global_dof_index > &  dof_indices  ) 
Set the Level DoF indices of this cell to the given values.
void DoFCellAccessor< dim, spacedim, lda >::update_cell_dof_indices_cache 
Update the cache in which we store the dof indices of this cell.
Definition at line 108 of file dof_accessor.cc.
const FiniteElement< dimension_, space_dimension_ > & DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::get_future_fe  (  )  const 
Return the finite element that will be assigned to this cell next time the triangulation gets refined and coarsened. If no future finite element has been specified for this cell via the set_future_fe_index() function, the active one will remain unchanged, in which case the active finite element will be returned.
For DoFHandlers without hpcapabilities enabled, this is of course always the same element, independent of the cell we are presently on, but for hp DoFHandler objects this may change from cell to cell.
unsigned int DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::future_fe_index  (  )  const 
Return the fe_index of the finite element that will be assigned to this cell next time the triangulation gets refined and coarsened. If no future finite element has been specified for this cell via the set_future_fe_index() function, the active one will remain unchanged, in which case the fe_index of the active finite element will be returned.
void DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::set_future_fe_index  (  const unsigned int  i  )  const 
Set the fe_index of the finite element that will be assigned to this cell next time the triangulation gets refined and coarsened. A previously assigned future finite element will be overwritten.
See notes of future_fe_index() for information about restrictions on this functionality.
bool DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::future_fe_index_set  (  )  const 
Return whether a future finite element has been set.
See notes of future_fe_index() for information about restrictions on this functionality.
void DoFCellAccessor< dimension_, space_dimension_, level_dof_access >::clear_future_fe_index  (  )  const 
Revoke the future finite element assigned. Thus, the active finite element will remain unchanged next time the triangulation gets refined and coarsened.
See notes on future_fe_index() for information about restrictions on this functionality.

inherited 
Return a handle on the DoFHandler object which we are using.

inherited 
Implement the copy operator needed for the iterator classes.

inherited 
Copy operator used by the iterator class. Keeps the previously set dof handler, but sets the object coordinates of the TriaAccessor.

inlinestaticinherited 
Tell the caller whether get_active_or_mg_dof_indices() accesses active or level dofs.
Definition at line 369 of file dof_accessor.h.

inherited 
Pointer to the ith
line bounding this object. If the current object is a line itself, then the only valid index is i
equals to zero, and the function returns an iterator to itself.

inherited 
Pointer to the ith
quad bounding this object. If the current object is a quad itself, then the only valid index is i
equals to zero, and the function returns an iterator to itself.

inherited 
Return the global indices of the degrees of freedom located on this object in the standard ordering defined by the finite element (i.e., dofs on vertex 0, dofs on vertex 1, etc, dofs on line 0, dofs on line 1, etc, dofs on quad 0, etc.) This function is only available on active objects (see this glossary entry).
The cells needs to be an active cell (and not artificial in a parallel distributed computation).
The vector has to have the right size before being passed to this function.
The last argument denotes the finite element index. For the standard DoFHandler class, this value must be equal to its default value since that class only supports the same finite element on all cells anyway.
However, when the relevant DoFHandler object has hpcapabilities enabled, different finite element objects may be used on different cells. On faces between two cells, as well as vertices, there may therefore be two sets of degrees of freedom, one for each of the finite elements used on the adjacent cells. In order to specify which set of degrees of freedom to work on, the last argument is used to disambiguate. Finally, if this function is called for a cell object, there can only be a single set of degrees of freedom, and fe_index has to match the result of active_fe_index().
For cells, there is only a single possible finite element index (namely the one for that cell, returned by cell>active_fe_index
. Consequently, the derived DoFCellAccessor class has an overloaded version of this function that calls the present function with cell>active_fe_index
as last argument.

inherited 
Return the global multilevel indices of the degrees of freedom that live on the current object with respect to the given level within the multigrid hierarchy. The indices refer to the local numbering for the level this line lives on.

inherited 
Set the level DoF indices that are returned by get_mg_dof_indices.

inherited 
Global DoF index of the i degree associated with the vertexth
vertex of the present cell.
The last argument denotes the finite element index. For the standard DoFHandler class, this value must be equal to its default value since that class only supports the same finite element on all cells anyway.
However, when hpcapabilities are enabled, different finite element objects may be used on different cells. On faces between two cells, as well as vertices, there may therefore be two sets of degrees of freedom, one for each of the finite elements used on the adjacent cells. In order to specify which set of degrees of freedom to work on, the last argument is used to disambiguate. Finally, if this function is called for a cell object, there can only be a single set of degrees of freedom, and fe_index
has to match the result of cell>active_fe_index()
. Alternatively, if fe_index
is left to its default value when this function is called on a cell, then this is interpreted as equal to cell>active_fe_index()
.

inherited 
Return the global DoF index of the i
th degree of freedom associated with the vertex
th vertex on level level
. Also see vertex_dof_index().

inherited 
Index of the ith degree of freedom of this object.
The last argument denotes the finite element index. For the standard DoFHandler class, this value must be equal to its default value since that class only supports the same finite element on all cells anyway.
However, when hpcapabilities are enabled, different finite element objects may be used on different cells. On faces between two cells, as well as vertices, there may therefore be two sets of degrees of freedom, one for each of the finite elements used on the adjacent cells. In order to specify which set of degrees of freedom to work on, the last argument is used to disambiguate. Finally, if this function is called for a cell object, there can only be a single set of degrees of freedom, and fe_index has to match the result of active_fe_index().

inherited 
Return the dof_index on the given level. Also see dof_index.

inherited 
Return the number of finite elements that are active on a given object.
When hpcapabilities are disabled the answer is, of course, always one. However, when hpcapabilities are enabled, this isn't the case: If this is a cell, the answer is of course one. If it is a face, the answer may be one or two, depending on whether the two adjacent cells use the same finite element or not. If it is an edge in 3d, the possible return value may be one or any other value larger than that.

inherited 
Return the nth
active FE index on this object. For cells and all non hpobjects, there is only a single active FE index, so the argument must be equal to zero. For lowerdimensional hpobjects, there are n_active_fe_indices() active finite elements, and this function can be queried for their indices.

inherited 
Returns all active FE indices on this object.
The size of the returned set equals the number of finite elements that are active on this object.

inherited 
Return true if the finite element with given index is active on the present object. When the current DoFHandler does not have hp capabilities, this is of course the case only if fe_index
equals zero. For cells, it is the case if fe_index
equals active_fe_index() of this cell. For faces and other lower dimensional objects, there may be more than one fe_index
that are active on any given object (see n_active_fe_indices()).

inherited 
Return a reference to the finite element used on this object with the given fe_index
. fe_index
must be used on this object, i.e. fe_index_is_active(fe_index)
must return true.

staticinherited 
Exceptions for child classes

staticinherited 
Exception

staticinherited 
Exception

staticinherited 
Exception

staticinherited 
A function has been called for a cell which should be active, but is refined.

staticinherited 
Exception

inherited 
Compare for equality. Return true
if the two accessors refer to the same object.
The template parameters of this function allow for a comparison of very different objects. Therefore, some of them are disabled. Namely, if the dimension, or the dof handler of the two objects differ, an exception is generated. It can be expected that this is an unwanted comparison.
The template parameter level_dof_access2
is ignored, such that an iterator with level access can be equal to one with access to the active degrees of freedom.

inherited 
Compare for inequality. The boolean not of operator==().

protectedinherited 
Reset the DoF handler pointer.

protectedinherited 
Set the index of the ith degree of freedom of this object to index
.
The last argument denotes the finite element index. For the standard DoFHandler class, this value must be equal to its default value since that class only supports the same finite element on all cells anyway.
However, when the relevant DoFHandler has hpcapabilities, different finite element objects may be used on different cells. On faces between two cells, as well as vertices, there may therefore be two sets of degrees of freedom, one for each of the finite elements used on the adjacent cells. In order to specify which set of degrees of freedom to work on, the last argument is used to disambiguate. Finally, if this function is called for a cell object, there can only be a single set of degrees of freedom, and fe_index has to match the result of active_fe_index().

protectedinherited 

protectedinherited 

friend 
Manage the distribution and numbering of the degrees of freedom for hp FEM algorithms. This class satisfies the MeshType concept requirements.
The purpose of this class is to allow for an enumeration of degrees of freedom in the same way as the DoFHandler class, but it allows to use a different finite element on every cell. To this end, one assigns an active_fe_index
to every cell that indicates which element within a collection of finite elements (represented by an object of type hp::FECollection) is the one that lives on this cell. The class then enumerates the degree of freedom associated with these finite elements on each cell of a triangulation and, if possible, identifies degrees of freedom at the interfaces of cells if they match. If neighboring cells have degrees of freedom along the common interface that do not immediate match (for example, if you have \(Q_2\) and \(Q_3\) elements meeting at a common face), then one needs to compute constraints to ensure that the resulting finite element space on the mesh remains conforming.
The whole process of working with objects of this type is explained in step27. Many of the algorithms this class implements are described in the hppaper.
The typical workflow for using this class is to create a mesh, assign an active FE index to every active cell, calls hp::DoFHandler::distribute_dofs(), and then assemble a linear system and solve a problem on this finite element space. However, one can skip assigning active FE indices upon mesh refinement in certain circumstances. In particular, the following rules apply:
When this class is used with either a parallel::shared::Triangulation or a parallel::distributed::Triangulation, you can only set active FE indices on cells that are locally owned, using a call such as cell>set_active_fe_index(...)
. On the other hand, setting the active FE index on ghost or artificial cells is not allowed.
Ghost cells do acquire the information what element is active on them, however: whenever you call hp::DoFHandler::distribute_dofs(), all processors that participate in the parallel mesh exchange information in such a way that the active FE index on ghost cells equals the active FE index that was set on that processor that owned that particular ghost cell. Consequently, one can query the active_fe_index
on ghost cells, just not set it by hand.
On artificial cells, no information is available about the active_fe_index
used there. That's because we don't even know whether these cells exist at all, and even if they did, the current processor does not know anything specific about them. See the glossary entry on artificial cells for more information.
During refinement and coarsening, information about the active_fe_index
of each cell will be automatically transferred.
However, using a parallel::distributed::Triangulation with an hp::DoFHandler requires additional attention during serialization, since no information on active FE indices will be automatically transferred. This has to be done manually using the prepare_for_serialization_of_active_fe_indices() and deserialize_active_fe_indices() functions. The former has to be called before parallel::distributed::Triangulation::save() is invoked, and the latter needs to be run after parallel::distributed::Triangulation::load(). If further data will be attached to the triangulation via the parallel::distributed::CellDataTransfer, parallel::distributed::SolutionTransfer, or Particles::ParticleHandler classes, all corresponding preparation and deserialization function calls need to happen in the same order. Consult the documentation of parallel::distributed::SolutionTransfer for more information.
Definition at line 2131 of file dof_accessor.h.

friend 
Definition at line 2132 of file dof_accessor.h.

static 
Extract dimension from DoFHandler.
Definition at line 1336 of file dof_accessor.h.

static 
Extract space dimension from DoFHandler.
Definition at line 1341 of file dof_accessor.h.

staticconstexprinherited 
A static variable that allows users of this class to discover the value of the second template argument.
Definition at line 220 of file dof_accessor.h.

staticconstexprinherited 
A static variable that allows users of this class to discover the value of the third template argument.
Definition at line 226 of file dof_accessor.h.

protectedinherited 
Store the address of the DoFHandler object to be accessed.
Definition at line 662 of file dof_accessor.h.