Reference documentation for deal.II version Git 7e3e0f8 2017-12-13 08:28:15 -0500
Public Types | Public Member Functions | Protected Member Functions | Protected Attributes | Private Member Functions | Private Attributes | List of all members
MatrixFreeOperators::Base< dim, VectorType > Class Template Referenceabstract

#include <deal.II/matrix_free/operators.h>

Inheritance diagram for MatrixFreeOperators::Base< dim, VectorType >:
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Public Types

typedef VectorType::value_type value_type
 
typedef VectorType::size_type size_type
 

Public Member Functions

 Base ()
 
virtual ~Base ()=default
 
virtual void clear ()
 
void initialize (std::shared_ptr< const MatrixFree< dim, value_type > > data, const std::vector< unsigned int > &selected_row_blocks=std::vector< unsigned int >(), const std::vector< unsigned int > &selected_column_blocks=std::vector< unsigned int >())
 
void initialize (std::shared_ptr< const MatrixFree< dim, value_type > > data, const MGConstrainedDoFs &mg_constrained_dofs, const unsigned int level, const std::vector< unsigned int > &selected_row_blocks=std::vector< unsigned int >())
 
void initialize (std::shared_ptr< const MatrixFree< dim, value_type > > data_, const std::vector< MGConstrainedDoFs > &mg_constrained_dofs, const unsigned int level, const std::vector< unsigned int > &selected_row_blocks=std::vector< unsigned int >())
 
size_type m () const
 
size_type n () const
 
void vmult_interface_down (VectorType &dst, const VectorType &src) const
 
void vmult_interface_up (VectorType &dst, const VectorType &src) const
 
void vmult (VectorType &dst, const VectorType &src) const
 
void Tvmult (VectorType &dst, const VectorType &src) const
 
void vmult_add (VectorType &dst, const VectorType &src) const
 
void Tvmult_add (VectorType &dst, const VectorType &src) const
 
value_type el (const unsigned int row, const unsigned int col) const
 
virtual std::size_t memory_consumption () const
 
void initialize_dof_vector (VectorType &vec) const
 
virtual void compute_diagonal ()=0
 
std::shared_ptr< const MatrixFree< dim, value_type > > get_matrix_free () const
 
const std::shared_ptr< DiagonalMatrix< VectorType > > & get_matrix_diagonal_inverse () const
 
const std::shared_ptr< DiagonalMatrix< VectorType > > & get_matrix_diagonal () const
 
void precondition_Jacobi (VectorType &dst, const VectorType &src, const value_type omega) const
 
- Public Member Functions inherited from Subscriptor
 Subscriptor ()
 
 Subscriptor (const Subscriptor &)
 
 Subscriptor (Subscriptor &&)
 
virtual ~Subscriptor ()
 
Subscriptoroperator= (const Subscriptor &)
 
Subscriptoroperator= (Subscriptor &&)
 
void subscribe (const char *identifier=nullptr) const
 
void unsubscribe (const char *identifier=nullptr) const
 
unsigned int n_subscriptions () const
 
void list_subscribers () const
 
template<class Archive >
void serialize (Archive &ar, const unsigned int version)
 

Protected Member Functions

void preprocess_constraints (VectorType &dst, const VectorType &src) const
 
void postprocess_constraints (VectorType &dst, const VectorType &src) const
 
void set_constrained_entries_to_one (VectorType &dst) const
 
virtual void apply_add (VectorType &dst, const VectorType &src) const =0
 
virtual void Tapply_add (VectorType &dst, const VectorType &src) const
 

Protected Attributes

std::shared_ptr< const MatrixFree< dim, value_type > > data
 
std::shared_ptr< DiagonalMatrix< VectorType > > diagonal_entries
 
std::shared_ptr< DiagonalMatrix< VectorType > > inverse_diagonal_entries
 
std::vector< unsigned int > selected_rows
 
std::vector< unsigned int > selected_columns
 

Private Member Functions

void mult_add (VectorType &dst, const VectorType &src, const bool transpose) const
 
void adjust_ghost_range_if_necessary (const VectorType &vec, const bool is_row) const
 

Private Attributes

std::vector< std::vector< unsigned int > > edge_constrained_indices
 
std::vector< std::vector< std::pair< value_type, value_type > > > edge_constrained_values
 
bool have_interface_matrices
 

Additional Inherited Members

- Static Public Member Functions inherited from Subscriptor
static::ExceptionBase & ExcInUse (int arg1, char *arg2, std::string &arg3)
 
static::ExceptionBase & ExcNoSubscriber (char *arg1, char *arg2)
 

Detailed Description

template<int dim, typename VectorType = LinearAlgebra::distributed::Vector<double>>
class MatrixFreeOperators::Base< dim, VectorType >

Abstract base class for matrix-free operators which can be used both at the finest mesh or at a certain level in geometric multigrid.

A derived class has to implement apply_add() method as well as compute_diagonal() to initialize the protected member inverse_diagonal_entries and/or diagonal_entries. In case of a non-symmetric operator, Tapply_add() should be additionally implemented.

Currently, the only supported vectors are LinearAlgebra::distributed::Vector and LinearAlgebra::distributed::BlockVector.

Selective use of blocks in MatrixFree

MatrixFree allows to use several DoFHandler/ConstraintMatrix combinations by passing an std::vector with pointers to the respective objects into the MatrixFree::reinit function. This class supports to select only some of the blocks in the underlying MatrixFree object by optional integer lists that specify the chosen blocks.

One application of constructing a matrix-free operator only on selected blocks would be the setting of the step-32 tutorial program: This problem has three blocks, one for the velocity, one for the pressure, and one for temperature. The time lag scheme used for temporal evolution splits the temperature equation away from the Stokes system in velocity and pressure. However, there are cross terms like the velocity that enters the temperature advection-diffusion equation or the temperature that enters the right hand side of the velocity. In order to be sure that MatrixFree uses the same integer indexing to the different blocks, one needs to put all the three blocks into the same MatrixFree object. However, when solving a linear system the operators involved either address the first two in the Stokes solver, or the last one for the temperature solver. In the former case, a BlockVector of two components would be selected with a vector selecting the blocks {0, 1} in MatrixFree, whereas in the latter, a non-block vector selecting the block {2} would be used.

A second application of selection is in problems with a Newton-type iteration or problems with inhomogeneous boundary conditions. In such a case, one has to deal with two different sets of constraints: One set of constraints applies to the solution vector which might include hanging node constraints or periodicity constraints but no constraints on inhomogeneous Dirichlet boundaries. Before the nonlinear iteration, the boundary values are set to the expected value in the vector, representing the initial guess. In each iteration of the Newton method, a linear system subject to zero Dirichlet boundary conditions is solved that is then added to the initial guess. This setup can be realized by using a vector of two pointers pointing to the same DoFHandler object and a vector of two pointers to the two ConstraintMatrix objects. If the first constraint matrix is the one including the zero Dirichlet constraints, one would give an std::vector<unsigned int>(1, 0) to the initialize() function, i.e., a vector of length 1 that selects exactly the first constraint matrix with index 0.

For systems of PDEs where the different blocks of MatrixFree are associated with different physical components of the equations, adding another block with a different ConstraintMatrix argument solely for the purpose of boundary conditions might lead to cumbersome index handling. Instead, one could set up a second MatrixFree instance with the different constraint matrix but the same interpretation of blocks, and use that for interpolating inhomogeneous boundary conditions (see also the discussion in the results section of the step-37 tutorial program):

matrix_free_inhomogeneous.reinit(dof_handler, constraints_no_dirichlet,
quadrature, additional_data);
operator_inhomogeneous.initialize(matrix_free_inhomogeneous, selected_blocks);
matrix_free_inhomogeneous.initialize_dof_vector(inhomogeneity);
constraints_with_dirichlet.distribute(inhomogeneity);
operator_inhomogeneous.vmult(system_rhs, inhomogeneity);
system_rhs *= -1.;
// proceed with other terms from right hand side...
Author
Denis Davydov, Daniel Arndt, Martin Kronbichler, 2016, 2017

Definition at line 185 of file operators.h.

Member Typedef Documentation

template<int dim, typename VectorType = LinearAlgebra::distributed::Vector<double>>
typedef VectorType::value_type MatrixFreeOperators::Base< dim, VectorType >::value_type

Number typedef.

Definition at line 191 of file operators.h.

template<int dim, typename VectorType = LinearAlgebra::distributed::Vector<double>>
typedef VectorType::size_type MatrixFreeOperators::Base< dim, VectorType >::size_type

size_type needed for preconditioner classes.

Definition at line 196 of file operators.h.

Constructor & Destructor Documentation

template<int dim, typename VectorType >
MatrixFreeOperators::Base< dim, VectorType >::Base ( )

Default constructor.

Definition at line 932 of file operators.h.

template<int dim, typename VectorType = LinearAlgebra::distributed::Vector<double>>
virtual MatrixFreeOperators::Base< dim, VectorType >::~Base ( )
virtualdefault

Virtual destructor.

Member Function Documentation

template<int dim, typename VectorType >
void MatrixFreeOperators::Base< dim, VectorType >::clear ( )
virtual

Release all memory and return to a state just like after having called the default constructor.

Reimplemented in MatrixFreeOperators::LaplaceOperator< dim, fe_degree, n_q_points_1d, n_components, VectorType >.

Definition at line 970 of file operators.h.

template<int dim, typename VectorType = LinearAlgebra::distributed::Vector<double>>
void MatrixFreeOperators::Base< dim, VectorType >::initialize ( std::shared_ptr< const MatrixFree< dim, value_type > >  data,
const std::vector< unsigned int > &  selected_row_blocks = std::vector< unsigned int >(),
const std::vector< unsigned int > &  selected_column_blocks = std::vector< unsigned int >() 
)

Initialize operator on fine scale.

The optional selection vector allows to choose only some components from the underlying MatrixFree object, e.g. just a single one. The entry selected_row_blocks[i] in the vector chooses the DoFHandler and ConstraintMatrix object that was given as the selected_row_blocks[i]-th argument to the MatrixFree::reinit() call. Different arguments for rows and columns also make it possible to select non-diagonal blocks or rectangular blocks. If the row vector is empty, all components are selected, otherwise its size must be smaller or equal to MatrixFree::n_components() and all indices need to be unique and within the range of 0 and MatrixFree::n_components(). If the column selection vector is empty, it is taken the same as the row selection, defining a diagonal block.

template<int dim, typename VectorType = LinearAlgebra::distributed::Vector<double>>
void MatrixFreeOperators::Base< dim, VectorType >::initialize ( std::shared_ptr< const MatrixFree< dim, value_type > >  data,
const MGConstrainedDoFs mg_constrained_dofs,
const unsigned int  level,
const std::vector< unsigned int > &  selected_row_blocks = std::vector< unsigned int >() 
)

Initialize operator on a level level for a single FiniteElement.

The optional selection vector allows to choose only some components from the underlying MatrixFree object, e.g. just a single one. The entry selected_row_blocks[i] in the vector chooses the DoFHandler and ConstraintMatrix object that was given as the selected_row_blocks[i]-th argument to the MatrixFree::reinit() call. Since a multigrid operator is always associated to inverting a matrix and thus represents a diagonal block, the same vector for rows and columns is used as opposed to the non-level initialization function. If empty, all components are selected.

template<int dim, typename VectorType >
void MatrixFreeOperators::Base< dim, VectorType >::initialize ( std::shared_ptr< const MatrixFree< dim, value_type > >  data_,
const std::vector< MGConstrainedDoFs > &  mg_constrained_dofs,
const unsigned int  level,
const std::vector< unsigned int > &  selected_row_blocks = std::vector<unsigned int>() 
)

Initialize operator on a level level for multiple FiniteElement objects.

The optional selection vector allows to choose only some components from the underlying MatrixFree object, e.g. just a single one. The entry selected_row_blocks[i] in the vector chooses the DoFHandler and ConstraintMatrix object that was given as the selected_row_blocks[i]-th argument to the MatrixFree::reinit() call. Since a multigrid operator is always associated to inverting a matrix and thus represents a diagonal block, the same vector for rows and columns is used as opposed to the non-level initialization function. If empty, all components are selected.

Definition at line 1084 of file operators.h.

template<int dim, typename VectorType >
Base< dim, VectorType >::size_type MatrixFreeOperators::Base< dim, VectorType >::m ( ) const

Return the dimension of the codomain (or range) space.

Definition at line 942 of file operators.h.

template<int dim, typename VectorType >
Base< dim, VectorType >::size_type MatrixFreeOperators::Base< dim, VectorType >::n ( ) const

Return the dimension of the domain space.

Definition at line 956 of file operators.h.

template<int dim, typename VectorType>
void MatrixFreeOperators::Base< dim, VectorType >::vmult_interface_down ( VectorType &  dst,
const VectorType &  src 
) const

vmult operator for interface.

Definition at line 1309 of file operators.h.

template<int dim, typename VectorType>
void MatrixFreeOperators::Base< dim, VectorType >::vmult_interface_up ( VectorType &  dst,
const VectorType &  src 
) const

vmult operator for interface.

Definition at line 1361 of file operators.h.

template<int dim, typename VectorType>
void MatrixFreeOperators::Base< dim, VectorType >::vmult ( VectorType &  dst,
const VectorType &  src 
) const

Matrix-vector multiplication.

Definition at line 1167 of file operators.h.

template<int dim, typename VectorType>
void MatrixFreeOperators::Base< dim, VectorType >::Tvmult ( VectorType &  dst,
const VectorType &  src 
) const

Transpose matrix-vector multiplication.

Definition at line 1399 of file operators.h.

template<int dim, typename VectorType>
void MatrixFreeOperators::Base< dim, VectorType >::vmult_add ( VectorType &  dst,
const VectorType &  src 
) const

Adding Matrix-vector multiplication.

Definition at line 1179 of file operators.h.

template<int dim, typename VectorType>
void MatrixFreeOperators::Base< dim, VectorType >::Tvmult_add ( VectorType &  dst,
const VectorType &  src 
) const

Adding transpose matrix-vector multiplication.

Definition at line 1189 of file operators.h.

template<int dim, typename VectorType >
Base< dim, VectorType >::value_type MatrixFreeOperators::Base< dim, VectorType >::el ( const unsigned int  row,
const unsigned int  col 
) const

Return the value of the matrix entry (row,col). In matrix-free context this function is valid only for row==col when diagonal is initialized.

Definition at line 980 of file operators.h.

template<int dim, typename VectorType >
std::size_t MatrixFreeOperators::Base< dim, VectorType >::memory_consumption ( ) const
virtual

Determine an estimate for the memory consumption (in bytes) of this object.

Definition at line 1411 of file operators.h.

template<int dim, typename VectorType>
void MatrixFreeOperators::Base< dim, VectorType >::initialize_dof_vector ( VectorType &  vec) const

A wrapper for initialize_dof_vector() of MatrixFree object.

Definition at line 994 of file operators.h.

template<int dim, typename VectorType = LinearAlgebra::distributed::Vector<double>>
virtual void MatrixFreeOperators::Base< dim, VectorType >::compute_diagonal ( )
pure virtual

Compute diagonal of this operator.

A derived class needs to implement this function and resize and fill the protected member inverse_diagonal_entries and/or diagonal_entries accordingly.

Implemented in MatrixFreeOperators::LaplaceOperator< dim, fe_degree, n_q_points_1d, n_components, VectorType >, and MatrixFreeOperators::MassOperator< dim, fe_degree, n_q_points_1d, n_components, VectorType >.

template<int dim, typename VectorType >
std::shared_ptr< const MatrixFree< dim, typename Base< dim, VectorType >::value_type > > MatrixFreeOperators::Base< dim, VectorType >::get_matrix_free ( ) const

Get read access to the MatrixFree object stored with this operator.

Definition at line 1421 of file operators.h.

template<int dim, typename VectorType >
const std::shared_ptr< DiagonalMatrix< VectorType > > & MatrixFreeOperators::Base< dim, VectorType >::get_matrix_diagonal_inverse ( ) const

Get read access to the inverse diagonal of this operator.

Definition at line 1430 of file operators.h.

template<int dim, typename VectorType >
const std::shared_ptr< DiagonalMatrix< VectorType > > & MatrixFreeOperators::Base< dim, VectorType >::get_matrix_diagonal ( ) const

Get read access to the diagonal of this operator.

Definition at line 1441 of file operators.h.

template<int dim, typename VectorType = LinearAlgebra::distributed::Vector<double>>
void MatrixFreeOperators::Base< dim, VectorType >::precondition_Jacobi ( VectorType &  dst,
const VectorType &  src,
const value_type  omega 
) const

Apply the Jacobi preconditioner, which multiplies every element of the src vector by the inverse of the respective diagonal element and multiplies the result with the relaxation factor omega.

Definition at line 1462 of file operators.h.

template<int dim, typename VectorType>
void MatrixFreeOperators::Base< dim, VectorType >::preprocess_constraints ( VectorType &  dst,
const VectorType &  src 
) const
protected

Perform necessary operations related to constraints before calling apply_add() or Tapply_add() inside mult_add().

Definition at line 1231 of file operators.h.

template<int dim, typename VectorType>
void MatrixFreeOperators::Base< dim, VectorType >::postprocess_constraints ( VectorType &  dst,
const VectorType &  src 
) const
protected

Perform necessary operations related to constraints after calling apply_add() or Tapply_add() inside mult_add().

Definition at line 1276 of file operators.h.

template<int dim, typename VectorType>
void MatrixFreeOperators::Base< dim, VectorType >::set_constrained_entries_to_one ( VectorType &  dst) const
protected

Set constrained entries (both from hanging nodes and edge constraints) of dst to one.

Definition at line 1150 of file operators.h.

template<int dim, typename VectorType = LinearAlgebra::distributed::Vector<double>>
virtual void MatrixFreeOperators::Base< dim, VectorType >::apply_add ( VectorType &  dst,
const VectorType &  src 
) const
protectedpure virtual
template<int dim, typename VectorType>
void MatrixFreeOperators::Base< dim, VectorType >::Tapply_add ( VectorType &  dst,
const VectorType &  src 
) const
protectedvirtual

Apply transpose operator to src and add result in dst.

Default implementation is to call apply_add().

Definition at line 1452 of file operators.h.

template<int dim, typename VectorType>
void MatrixFreeOperators::Base< dim, VectorType >::mult_add ( VectorType &  dst,
const VectorType &  src,
const bool  transpose 
) const
private

Function which implements vmult_add (transpose = false) and Tvmult_add (transpose = true).

Definition at line 1257 of file operators.h.

template<int dim, typename VectorType>
void MatrixFreeOperators::Base< dim, VectorType >::adjust_ghost_range_if_necessary ( const VectorType &  vec,
const bool  is_row 
) const
private

Adjust the ghost range of the vectors to the storage requirements of the underlying MatrixFree class. This is used inside the mult_add() as well as vmult_interface_up() and vmult_interface_down() methods in order to ensure that the cell loops will be able to access the ghost indices with the correct local indices.

Definition at line 1199 of file operators.h.

Member Data Documentation

template<int dim, typename VectorType = LinearAlgebra::distributed::Vector<double>>
std::shared_ptr<const MatrixFree<dim,value_type> > MatrixFreeOperators::Base< dim, VectorType >::data
protected

MatrixFree object to be used with this operator.

Definition at line 408 of file operators.h.

template<int dim, typename VectorType = LinearAlgebra::distributed::Vector<double>>
std::shared_ptr<DiagonalMatrix<VectorType > > MatrixFreeOperators::Base< dim, VectorType >::diagonal_entries
protected

A shared pointer to a diagonal matrix that stores the diagonal elements as a vector.

Definition at line 414 of file operators.h.

template<int dim, typename VectorType = LinearAlgebra::distributed::Vector<double>>
std::shared_ptr<DiagonalMatrix<VectorType > > MatrixFreeOperators::Base< dim, VectorType >::inverse_diagonal_entries
protected

A shared pointer to a diagonal matrix that stores the inverse of diagonal elements as a vector.

Definition at line 420 of file operators.h.

template<int dim, typename VectorType = LinearAlgebra::distributed::Vector<double>>
std::vector<unsigned int> MatrixFreeOperators::Base< dim, VectorType >::selected_rows
protected

A vector which defines the selection of sub-components of MatrixFree for the rows of the matrix representation.

Definition at line 426 of file operators.h.

template<int dim, typename VectorType = LinearAlgebra::distributed::Vector<double>>
std::vector<unsigned int> MatrixFreeOperators::Base< dim, VectorType >::selected_columns
protected

A vector which defines the selection of sub-components of MatrixFree for the columns of the matrix representation.

Definition at line 432 of file operators.h.

template<int dim, typename VectorType = LinearAlgebra::distributed::Vector<double>>
std::vector<std::vector<unsigned int> > MatrixFreeOperators::Base< dim, VectorType >::edge_constrained_indices
private

Indices of DoFs on edge in case the operator is used in GMG context.

Definition at line 439 of file operators.h.

template<int dim, typename VectorType = LinearAlgebra::distributed::Vector<double>>
std::vector<std::vector<std::pair<value_type,value_type> > > MatrixFreeOperators::Base< dim, VectorType >::edge_constrained_values
mutableprivate

Auxiliary vector.

Definition at line 445 of file operators.h.

template<int dim, typename VectorType = LinearAlgebra::distributed::Vector<double>>
bool MatrixFreeOperators::Base< dim, VectorType >::have_interface_matrices
private

A flag which determines whether or not this operator has interface matrices in GMG context.

Definition at line 451 of file operators.h.


The documentation for this class was generated from the following file: