Reference documentation for deal.II version Git 5a2787e538 2021-09-21 14:55:10 -0600
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Classes | Public Types | Public Member Functions | Static Public Member Functions | Protected Member Functions | Protected Attributes | Private Member Functions | Friends | List of all members
PETScWrappers::SparseMatrix Class Reference

#include <deal.II/lac/petsc_sparse_matrix.h>

Inheritance diagram for PETScWrappers::SparseMatrix:
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Classes

struct  Traits
 

Public Types

using const_iterator = MatrixIterators::const_iterator
 
using size_type = types::global_dof_index
 
using value_type = PetscScalar
 

Public Member Functions

 SparseMatrix ()
 
 SparseMatrix (const size_type m, const size_type n, const size_type n_nonzero_per_row, const bool is_symmetric=false)
 
 SparseMatrix (const size_type m, const size_type n, const std::vector< size_type > &row_lengths, const bool is_symmetric=false)
 
template<typename SparsityPatternType >
 SparseMatrix (const SparsityPatternType &sparsity_pattern, const bool preset_nonzero_locations=true)
 
SparseMatrixoperator= (const double d)
 
 SparseMatrix (const SparseMatrix &)=delete
 
SparseMatrixoperator= (const SparseMatrix &)=delete
 
void reinit (const size_type m, const size_type n, const size_type n_nonzero_per_row, const bool is_symmetric=false)
 
void reinit (const size_type m, const size_type n, const std::vector< size_type > &row_lengths, const bool is_symmetric=false)
 
template<typename SparsityPatternType >
void reinit (const SparsityPatternType &sparsity_pattern, const bool preset_nonzero_locations=true)
 
virtual const MPI_Commget_mpi_communicator () const override
 
size_t m () const
 
size_t n () const
 
void mmult (SparseMatrix &C, const SparseMatrix &B, const MPI::Vector &V=MPI::Vector()) const
 
void Tmmult (SparseMatrix &C, const SparseMatrix &B, const MPI::Vector &V=MPI::Vector()) const
 
void clear ()
 
void set (const size_type i, const size_type j, const PetscScalar value)
 
void set (const std::vector< size_type > &indices, const FullMatrix< PetscScalar > &full_matrix, const bool elide_zero_values=false)
 
void set (const std::vector< size_type > &row_indices, const std::vector< size_type > &col_indices, const FullMatrix< PetscScalar > &full_matrix, const bool elide_zero_values=false)
 
void set (const size_type row, const std::vector< size_type > &col_indices, const std::vector< PetscScalar > &values, const bool elide_zero_values=false)
 
void set (const size_type row, const size_type n_cols, const size_type *col_indices, const PetscScalar *values, const bool elide_zero_values=false)
 
void add (const size_type i, const size_type j, const PetscScalar value)
 
void add (const std::vector< size_type > &indices, const FullMatrix< PetscScalar > &full_matrix, const bool elide_zero_values=true)
 
void add (const std::vector< size_type > &row_indices, const std::vector< size_type > &col_indices, const FullMatrix< PetscScalar > &full_matrix, const bool elide_zero_values=true)
 
void add (const size_type row, const std::vector< size_type > &col_indices, const std::vector< PetscScalar > &values, const bool elide_zero_values=true)
 
void add (const size_type row, const size_type n_cols, const size_type *col_indices, const PetscScalar *values, const bool elide_zero_values=true, const bool col_indices_are_sorted=false)
 
MatrixBaseadd (const PetscScalar factor, const MatrixBase &other)
 
void clear_row (const size_type row, const PetscScalar new_diag_value=0)
 
void clear_rows (const std::vector< size_type > &rows, const PetscScalar new_diag_value=0)
 
void compress (const VectorOperation::values operation)
 
PetscScalar operator() (const size_type i, const size_type j) const
 
PetscScalar el (const size_type i, const size_type j) const
 
PetscScalar diag_element (const size_type i) const
 
size_type local_size () const
 
std::pair< size_type, size_typelocal_range () const
 
bool in_local_range (const size_type index) const
 
size_type n_nonzero_elements () const
 
size_type row_length (const size_type row) const
 
PetscReal l1_norm () const
 
PetscReal linfty_norm () const
 
PetscReal frobenius_norm () const
 
PetscScalar matrix_norm_square (const VectorBase &v) const
 
PetscScalar matrix_scalar_product (const VectorBase &u, const VectorBase &v) const
 
PetscScalar trace () const
 
MatrixBaseoperator*= (const PetscScalar factor)
 
MatrixBaseoperator/= (const PetscScalar factor)
 
void vmult (VectorBase &dst, const VectorBase &src) const
 
void Tvmult (VectorBase &dst, const VectorBase &src) const
 
void vmult_add (VectorBase &dst, const VectorBase &src) const
 
void Tvmult_add (VectorBase &dst, const VectorBase &src) const
 
PetscScalar residual (VectorBase &dst, const VectorBase &x, const VectorBase &b) const
 
const_iterator begin () const
 
const_iterator begin (const size_type r) const
 
const_iterator end () const
 
const_iterator end (const size_type r) const
 
 operator Mat () const
 
Mat & petsc_matrix ()
 
void transpose ()
 
PetscBool is_symmetric (const double tolerance=1.e-12)
 
PetscBool is_hermitian (const double tolerance=1.e-12)
 
void write_ascii (const PetscViewerFormat format=PETSC_VIEWER_DEFAULT)
 
void print (std::ostream &out, const bool alternative_output=false) const
 
std::size_t memory_consumption () const
 
template<class Archive >
void serialize (Archive &ar, const unsigned int version)
 
Subscriptor functionality

Classes derived from Subscriptor provide a facility to subscribe to this object. This is mostly used by the SmartPointer class.

void subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const
 
void unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const
 
unsigned int n_subscriptions () const
 
template<typename StreamType >
void list_subscribers (StreamType &stream) const
 
void list_subscribers () const
 

Static Public Member Functions

static ::ExceptionBaseExcSourceEqualsDestination ()
 
static ::ExceptionBaseExcWrongMode (int arg1, int arg2)
 
static ::ExceptionBaseExcInUse (int arg1, std::string arg2, std::string arg3)
 
static ::ExceptionBaseExcNoSubscriber (std::string arg1, std::string arg2)
 

Protected Member Functions

void prepare_action (const VectorOperation::values new_action)
 
void assert_is_compressed ()
 
void prepare_add ()
 
void prepare_set ()
 
void mmult (MatrixBase &C, const MatrixBase &B, const VectorBase &V) const
 
void Tmmult (MatrixBase &C, const MatrixBase &B, const VectorBase &V) const
 

Protected Attributes

Mat matrix
 
VectorOperation::values last_action
 

Private Member Functions

void do_reinit (const size_type m, const size_type n, const size_type n_nonzero_per_row, const bool is_symmetric=false)
 
void do_reinit (const size_type m, const size_type n, const std::vector< size_type > &row_lengths, const bool is_symmetric=false)
 
template<typename SparsityPatternType >
void do_reinit (const SparsityPatternType &sparsity_pattern, const bool preset_nonzero_locations)
 

Friends

class BlockMatrixBase< SparseMatrix >
 

Detailed Description

Implementation of a sequential sparse matrix class based on PETSc. All the functionality is actually in the base class, except for the calls to generate a sequential sparse matrix. This is possible since PETSc only works on an abstract matrix type and internally distributes to functions that do the actual work depending on the actual matrix type (much like using virtual functions). Only the functions creating a matrix of specific type differ, and are implemented in this particular class.

Definition at line 51 of file petsc_sparse_matrix.h.

Member Typedef Documentation

◆ const_iterator

Declare an alias for the iterator class.

Definition at line 290 of file petsc_matrix_base.h.

◆ size_type

Declare type for container size.

Definition at line 295 of file petsc_matrix_base.h.

◆ value_type

using PETScWrappers::MatrixBase::value_type = PetscScalar
inherited

Declare an alias in analogy to all the other container classes.

Definition at line 300 of file petsc_matrix_base.h.

Constructor & Destructor Documentation

◆ SparseMatrix() [1/5]

SparseMatrix< number >::SparseMatrix ( )

Default constructor. Create an empty matrix.

Definition at line 30 of file petsc_sparse_matrix.cc.

◆ SparseMatrix() [2/5]

SparseMatrix< number >::SparseMatrix ( const size_type  m,
const size_type  n,
const size_type  n_nonzero_per_row,
const bool  is_symmetric = false 
)

Create a sparse matrix of dimensions m times n, with an initial guess of n_nonzero_per_row nonzero elements per row. PETSc is able to cope with the situation that more than this number of elements is later allocated for a row, but this involves copying data, and is thus expensive.

The is_symmetric flag determines whether we should tell PETSc that the matrix is going to be symmetric (as indicated by the call MatSetOption(mat, MAT_SYMMETRIC). Note that the PETSc documentation states that one cannot form an ILU decomposition of a matrix for which this flag has been set to true, only an ICC. The default value of this flag is false.

Definition at line 40 of file petsc_sparse_matrix.cc.

◆ SparseMatrix() [3/5]

SparseMatrix< number >::SparseMatrix ( const size_type  m,
const size_type  n,
const std::vector< size_type > &  row_lengths,
const bool  is_symmetric = false 
)

Initialize a rectangular matrix with m rows and n columns. The maximal number of nonzero entries for each row separately is given by the row_lengths array.

Just as for the other constructors: PETSc is able to cope with the situation that more than this number of elements is later allocated for a row, but this involves copying data, and is thus expensive.

The is_symmetric flag determines whether we should tell PETSc that the matrix is going to be symmetric (as indicated by the call MatSetOption(mat, MAT_SYMMETRIC). Note that the PETSc documentation states that one cannot form an ILU decomposition of a matrix for which this flag has been set to true, only an ICC. The default value of this flag is false.

Definition at line 50 of file petsc_sparse_matrix.cc.

◆ SparseMatrix() [4/5]

template<typename SparsityPatternType >
SparseMatrix< SparsityPatternType >::SparseMatrix ( const SparsityPatternType &  sparsity_pattern,
const bool  preset_nonzero_locations = true 
)
explicit

Initialize a sparse matrix using the given sparsity pattern.

Note that PETSc can be very slow if you do not provide it with a good estimate of the lengths of rows. Using the present function is a very efficient way to do this, as it uses the exact number of nonzero entries for each row of the matrix by using the given sparsity pattern argument. If the preset_nonzero_locations flag is true, this function in addition not only sets the correct row sizes up front, but also pre-allocated the correct nonzero entries in the matrix.

PETsc allows to later add additional nonzero entries to a matrix, by simply writing to these elements. However, this will then lead to additional memory allocations which are very inefficient and will greatly slow down your program. It is therefore significantly more efficient to get memory allocation right from the start.

Definition at line 61 of file petsc_sparse_matrix.cc.

◆ SparseMatrix() [5/5]

PETScWrappers::SparseMatrix::SparseMatrix ( const SparseMatrix )
delete

The copy constructor is deleted.

Member Function Documentation

◆ operator=() [1/2]

SparseMatrix & SparseMatrix< number >::operator= ( const double  d)

This operator assigns a scalar to a matrix. Since this does usually not make much sense (should we set all matrix entries to this value? Only the nonzero entries of the sparsity pattern?), this operation is only allowed if the actual value to be assigned is zero. This operator only exists to allow for the obvious notation matrix=0, which sets all elements of the matrix to zero, but keep the sparsity pattern previously used.

Definition at line 70 of file petsc_sparse_matrix.cc.

◆ operator=() [2/2]

SparseMatrix& PETScWrappers::SparseMatrix::operator= ( const SparseMatrix )
delete

The copy assignment operator is deleted.

◆ reinit() [1/3]

void SparseMatrix< number >::reinit ( const size_type  m,
const size_type  n,
const size_type  n_nonzero_per_row,
const bool  is_symmetric = false 
)

Throw away the present matrix and generate one that has the same properties as if it were created by the constructor of this class with the same argument list as the present function.

Definition at line 79 of file petsc_sparse_matrix.cc.

◆ reinit() [2/3]

void SparseMatrix< number >::reinit ( const size_type  m,
const size_type  n,
const std::vector< size_type > &  row_lengths,
const bool  is_symmetric = false 
)

Throw away the present matrix and generate one that has the same properties as if it were created by the constructor of this class with the same argument list as the present function.

Definition at line 95 of file petsc_sparse_matrix.cc.

◆ reinit() [3/3]

template<typename SparsityPatternType >
void SparseMatrix< SparsityPatternType >::reinit ( const SparsityPatternType &  sparsity_pattern,
const bool  preset_nonzero_locations = true 
)

Initialize a sparse matrix using the given sparsity pattern.

Note that PETSc can be very slow if you do not provide it with a good estimate of the lengths of rows. Using the present function is a very efficient way to do this, as it uses the exact number of nonzero entries for each row of the matrix by using the given sparsity pattern argument. If the preset_nonzero_locations flag is true, this function in addition not only sets the correct row sizes up front, but also pre-allocated the correct nonzero entries in the matrix.

PETsc allows to later add additional nonzero entries to a matrix, by simply writing to these elements. However, this will then lead to additional memory allocations which are very inefficient and will greatly slow down your program. It is therefore significantly more efficient to get memory allocation right from the start.

Despite the fact that it would seem to be an obvious win, setting the preset_nonzero_locations flag to true doesn't seem to accelerate program. Rather on the contrary, it seems to be able to slow down entire programs somewhat. This is surprising, since we can use efficient function calls into PETSc that allow to create multiple entries at once; nevertheless, given the fact that it is inefficient, the respective flag has a default value equal to false.

Definition at line 112 of file petsc_sparse_matrix.cc.

◆ get_mpi_communicator()

const MPI_Comm & SparseMatrix< number >::get_mpi_communicator ( ) const
overridevirtual

Return a reference to the MPI communicator object in use with this matrix. Since this is a sequential matrix, it returns the MPI_COMM_SELF communicator.

Implements PETScWrappers::MatrixBase.

Definition at line 126 of file petsc_sparse_matrix.cc.

◆ m()

size_t SparseMatrix< number >::m ( ) const

Return the number of rows of this matrix.

Definition at line 248 of file petsc_sparse_matrix.cc.

◆ n()

size_t SparseMatrix< number >::n ( ) const

Return the number of columns of this matrix.

Definition at line 258 of file petsc_sparse_matrix.cc.

◆ mmult() [1/2]

void SparseMatrix< number >::mmult ( SparseMatrix C,
const SparseMatrix B,
const MPI::Vector V = MPI::Vector() 
) const

Perform the matrix-matrix multiplication \(C = AB\), or, \(C = A \text{diag}(V) B\) given a compatible vector \(V\).

This function calls MatrixBase::mmult() to do the actual work.

Definition at line 268 of file petsc_sparse_matrix.cc.

◆ Tmmult() [1/2]

void SparseMatrix< number >::Tmmult ( SparseMatrix C,
const SparseMatrix B,
const MPI::Vector V = MPI::Vector() 
) const

Perform the matrix-matrix multiplication with the transpose of this, i.e., \(C = A^T B\), or, \(C = A^T \text{diag}(V) B\) given a compatible vector \(V\).

This function calls MatrixBase::Tmmult() to do the actual work.

Definition at line 279 of file petsc_sparse_matrix.cc.

◆ do_reinit() [1/3]

void SparseMatrix< number >::do_reinit ( const size_type  m,
const size_type  n,
const size_type  n_nonzero_per_row,
const bool  is_symmetric = false 
)
private

Do the actual work for the respective reinit() function and the matching constructor, i.e. create a matrix. Getting rid of the previous matrix is left to the caller.

Definition at line 138 of file petsc_sparse_matrix.cc.

◆ do_reinit() [2/3]

void SparseMatrix< number >::do_reinit ( const size_type  m,
const size_type  n,
const std::vector< size_type > &  row_lengths,
const bool  is_symmetric = false 
)
private

Same as previous function.

Definition at line 160 of file petsc_sparse_matrix.cc.

◆ do_reinit() [3/3]

template<typename SparsityPatternType >
void SparseMatrix< SparsityPatternType >::do_reinit ( const SparsityPatternType &  sparsity_pattern,
const bool  preset_nonzero_locations 
)
private

Same as previous function.

Definition at line 194 of file petsc_sparse_matrix.cc.

◆ clear()

void PETScWrappers::MatrixBase::clear ( )
inherited

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

Definition at line 92 of file petsc_matrix_base.cc.

◆ set() [1/5]

void PETScWrappers::MatrixBase::set ( const size_type  i,
const size_type  j,
const PetscScalar  value 
)
inherited

Set the element (i,j) to value.

If the present object (from a derived class of this one) happens to be a sparse matrix, then this function adds a new entry to the matrix if it didn't exist before, very much in contrast to the SparseMatrix class which throws an error if the entry does not exist. If value is not a finite number an exception is thrown.

◆ set() [2/5]

void PETScWrappers::MatrixBase::set ( const std::vector< size_type > &  indices,
const FullMatrix< PetscScalar > &  full_matrix,
const bool  elide_zero_values = false 
)
inherited

Set all elements given in a FullMatrix<double> into the sparse matrix locations given by indices. In other words, this function writes the elements in full_matrix into the calling matrix, using the local-to-global indexing specified by indices for both the rows and the columns of the matrix. This function assumes a quadratic sparse matrix and a quadratic full_matrix, the usual situation in FE calculations.

If the present object (from a derived class of this one) happens to be a sparse matrix, then this function adds some new entries to the matrix if they didn't exist before, very much in contrast to the SparseMatrix class which throws an error if the entry does not exist.

The optional parameter elide_zero_values can be used to specify whether zero values should be inserted anyway or they should be filtered away. The default value is false, i.e., even zero values are inserted/replaced.

◆ set() [3/5]

void PETScWrappers::MatrixBase::set ( const std::vector< size_type > &  row_indices,
const std::vector< size_type > &  col_indices,
const FullMatrix< PetscScalar > &  full_matrix,
const bool  elide_zero_values = false 
)
inherited

Same function as before, but now including the possibility to use rectangular full_matrices and different local-to-global indexing on rows and columns, respectively.

◆ set() [4/5]

void PETScWrappers::MatrixBase::set ( const size_type  row,
const std::vector< size_type > &  col_indices,
const std::vector< PetscScalar > &  values,
const bool  elide_zero_values = false 
)
inherited

Set several elements in the specified row of the matrix with column indices as given by col_indices to the respective value.

If the present object (from a derived class of this one) happens to be a sparse matrix, then this function adds some new entries to the matrix if they didn't exist before, very much in contrast to the SparseMatrix class which throws an error if the entry does not exist.

The optional parameter elide_zero_values can be used to specify whether zero values should be inserted anyway or they should be filtered away. The default value is false, i.e., even zero values are inserted/replaced.

◆ set() [5/5]

void PETScWrappers::MatrixBase::set ( const size_type  row,
const size_type  n_cols,
const size_type col_indices,
const PetscScalar *  values,
const bool  elide_zero_values = false 
)
inherited

Set several elements to values given by values in a given row in columns given by col_indices into the sparse matrix.

If the present object (from a derived class of this one) happens to be a sparse matrix, then this function adds some new entries to the matrix if they didn't exist before, very much in contrast to the SparseMatrix class which throws an error if the entry does not exist.

The optional parameter elide_zero_values can be used to specify whether zero values should be inserted anyway or they should be filtered away. The default value is false, i.e., even zero values are inserted/replaced.

◆ add() [1/6]

void PETScWrappers::MatrixBase::add ( const size_type  i,
const size_type  j,
const PetscScalar  value 
)
inherited

Add value to the element (i,j).

If the present object (from a derived class of this one) happens to be a sparse matrix, then this function adds a new entry to the matrix if it didn't exist before, very much in contrast to the SparseMatrix class which throws an error if the entry does not exist. If value is not a finite number an exception is thrown.

◆ add() [2/6]

void PETScWrappers::MatrixBase::add ( const std::vector< size_type > &  indices,
const FullMatrix< PetscScalar > &  full_matrix,
const bool  elide_zero_values = true 
)
inherited

Add all elements given in a FullMatrix<double> into sparse matrix locations given by indices. In other words, this function adds the elements in full_matrix to the respective entries in calling matrix, using the local-to-global indexing specified by indices for both the rows and the columns of the matrix. This function assumes a quadratic sparse matrix and a quadratic full_matrix, the usual situation in FE calculations.

If the present object (from a derived class of this one) happens to be a sparse matrix, then this function adds some new entries to the matrix if they didn't exist before, very much in contrast to the SparseMatrix class which throws an error if the entry does not exist.

The optional parameter elide_zero_values can be used to specify whether zero values should be added anyway or these should be filtered away and only non-zero data is added. The default value is true, i.e., zero values won't be added into the matrix.

◆ add() [3/6]

void PETScWrappers::MatrixBase::add ( const std::vector< size_type > &  row_indices,
const std::vector< size_type > &  col_indices,
const FullMatrix< PetscScalar > &  full_matrix,
const bool  elide_zero_values = true 
)
inherited

Same function as before, but now including the possibility to use rectangular full_matrices and different local-to-global indexing on rows and columns, respectively.

◆ add() [4/6]

void PETScWrappers::MatrixBase::add ( const size_type  row,
const std::vector< size_type > &  col_indices,
const std::vector< PetscScalar > &  values,
const bool  elide_zero_values = true 
)
inherited

Set several elements in the specified row of the matrix with column indices as given by col_indices to the respective value.

If the present object (from a derived class of this one) happens to be a sparse matrix, then this function adds some new entries to the matrix if they didn't exist before, very much in contrast to the SparseMatrix class which throws an error if the entry does not exist.

The optional parameter elide_zero_values can be used to specify whether zero values should be added anyway or these should be filtered away and only non-zero data is added. The default value is true, i.e., zero values won't be added into the matrix.

◆ add() [5/6]

void PETScWrappers::MatrixBase::add ( const size_type  row,
const size_type  n_cols,
const size_type col_indices,
const PetscScalar *  values,
const bool  elide_zero_values = true,
const bool  col_indices_are_sorted = false 
)
inherited

Add an array of values given by values in the given global matrix row at columns specified by col_indices in the sparse matrix.

If the present object (from a derived class of this one) happens to be a sparse matrix, then this function adds some new entries to the matrix if they didn't exist before, very much in contrast to the SparseMatrix class which throws an error if the entry does not exist.

The optional parameter elide_zero_values can be used to specify whether zero values should be added anyway or these should be filtered away and only non-zero data is added. The default value is true, i.e., zero values won't be added into the matrix.

◆ add() [6/6]

MatrixBase & PETScWrappers::MatrixBase::add ( const PetscScalar  factor,
const MatrixBase other 
)
inherited

Add the matrix other scaled by the factor factor to the current matrix.

Definition at line 430 of file petsc_matrix_base.cc.

◆ clear_row()

void PETScWrappers::MatrixBase::clear_row ( const size_type  row,
const PetscScalar  new_diag_value = 0 
)
inherited

Remove all elements from this row by setting them to zero. The function does not modify the number of allocated nonzero entries, it only sets some entries to zero. It may drop them from the sparsity pattern, though (but retains the allocated memory in case new entries are again added later).

This operation is used in eliminating constraints (e.g. due to hanging nodes) and makes sure that we can write this modification to the matrix without having to read entries (such as the locations of non-zero elements) from it – without this operation, removing constraints on parallel matrices is a rather complicated procedure.

The second parameter can be used to set the diagonal entry of this row to a value different from zero. The default is to set it to zero.

Definition at line 127 of file petsc_matrix_base.cc.

◆ clear_rows()

void PETScWrappers::MatrixBase::clear_rows ( const std::vector< size_type > &  rows,
const PetscScalar  new_diag_value = 0 
)
inherited

Same as clear_row(), except that it works on a number of rows at once.

The second parameter can be used to set the diagonal entries of all cleared rows to something different from zero. Note that all of these diagonal entries get the same value – if you want different values for the diagonal entries, you have to set them by hand.

Definition at line 136 of file petsc_matrix_base.cc.

◆ compress()

void PETScWrappers::MatrixBase::compress ( const VectorOperation::values  operation)
inherited

PETSc matrices store their own sparsity patterns. So, in analogy to our own SparsityPattern class, this function compresses the sparsity pattern and allows the resulting matrix to be used in all other operations where before only assembly functions were allowed. This function must therefore be called once you have assembled the matrix.

See Compressing distributed objects for more information.

Definition at line 193 of file petsc_matrix_base.cc.

◆ operator()()

PetscScalar PETScWrappers::MatrixBase::operator() ( const size_type  i,
const size_type  j 
) const
inherited

Return the value of the entry (i,j). This may be an expensive operation and you should always take care where to call this function. In contrast to the respective function in the MatrixBase class, we don't throw an exception if the respective entry doesn't exist in the sparsity pattern of this class, since PETSc does not transmit this information.

This function is therefore exactly equivalent to the el() function.

◆ el()

PetscScalar PETScWrappers::MatrixBase::el ( const size_type  i,
const size_type  j 
) const
inherited

Return the value of the matrix entry (i,j). If this entry does not exist in the sparsity pattern, then zero is returned. While this may be convenient in some cases, note that it is simple to write algorithms that are slow compared to an optimal solution, since the sparsity of the matrix is not used.

Definition at line 165 of file petsc_matrix_base.cc.

◆ diag_element()

PetscScalar PETScWrappers::MatrixBase::diag_element ( const size_type  i) const
inherited

Return the main diagonal element in the ith row. This function throws an error if the matrix is not quadratic.

Since we do not have direct access to the underlying data structure, this function is no faster than the elementwise access using the el() function. However, we provide this function for compatibility with the SparseMatrix class.

Definition at line 181 of file petsc_matrix_base.cc.

◆ local_size()

MatrixBase::size_type PETScWrappers::MatrixBase::local_size ( ) const
inherited

Return the local dimension of the matrix, i.e. the number of rows stored on the present MPI process. For sequential matrices, this number is the same as m(), but for parallel matrices it may be smaller.

To figure out which elements exactly are stored locally, use local_range().

Definition at line 263 of file petsc_matrix_base.cc.

◆ local_range()

std::pair< MatrixBase::size_type, MatrixBase::size_type > PETScWrappers::MatrixBase::local_range ( ) const
inherited

Return a pair of indices indicating which rows of this matrix are stored locally. The first number is the index of the first row stored, the second the index of the one past the last one that is stored locally. If this is a sequential matrix, then the result will be the pair (0,m()), otherwise it will be a pair (i,i+n), where n=local_size().

Definition at line 276 of file petsc_matrix_base.cc.

◆ in_local_range()

bool PETScWrappers::MatrixBase::in_local_range ( const size_type  index) const
inherited

Return whether index is in the local range or not, see also local_range().

◆ n_nonzero_elements()

MatrixBase::size_type PETScWrappers::MatrixBase::n_nonzero_elements ( ) const
inherited

Return the number of nonzero elements of this matrix. Actually, it returns the number of entries in the sparsity pattern; if any of the entries should happen to be zero, it is counted anyway.

Definition at line 290 of file petsc_matrix_base.cc.

◆ row_length()

MatrixBase::size_type PETScWrappers::MatrixBase::row_length ( const size_type  row) const
inherited

Number of entries in a specific row.

Definition at line 302 of file petsc_matrix_base.cc.

◆ l1_norm()

PetscReal PETScWrappers::MatrixBase::l1_norm ( ) const
inherited

Return the l1-norm of the matrix, that is \(|M|_1=max_{all columns j}\sum_{all rows i} |M_ij|\), (max. sum of columns). This is the natural matrix norm that is compatible to the l1-norm for vectors, i.e. \(|Mv|_1\leq |M|_1 |v|_1\). (cf. Haemmerlin-Hoffmann: Numerische Mathematik)

Definition at line 338 of file petsc_matrix_base.cc.

◆ linfty_norm()

PetscReal PETScWrappers::MatrixBase::linfty_norm ( ) const
inherited

Return the linfty-norm of the matrix, that is \(|M|_infty=max_{all rows i}\sum_{all columns j} |M_ij|\), (max. sum of rows). This is the natural matrix norm that is compatible to the linfty-norm of vectors, i.e. \(|Mv|_infty \leq |M|_infty |v|_infty\). (cf. Haemmerlin-Hoffmann: Numerische Mathematik)

Definition at line 351 of file petsc_matrix_base.cc.

◆ frobenius_norm()

PetscReal PETScWrappers::MatrixBase::frobenius_norm ( ) const
inherited

Return the frobenius norm of the matrix, i.e. the square root of the sum of squares of all entries in the matrix.

Definition at line 364 of file petsc_matrix_base.cc.

◆ matrix_norm_square()

PetscScalar PETScWrappers::MatrixBase::matrix_norm_square ( const VectorBase v) const
inherited

Return the square of the norm of the vector \(v\) with respect to the norm induced by this matrix, i.e. \(\left(v,Mv\right)\). This is useful, e.g. in the finite element context, where the \(L_2\) norm of a function equals the matrix norm with respect to the mass matrix of the vector representing the nodal values of the finite element function.

Obviously, the matrix needs to be quadratic for this operation.

The implementation of this function is not as efficient as the one in the MatrixBase class used in deal.II (i.e. the original one, not the PETSc wrapper class) since PETSc doesn't support this operation and needs a temporary vector.

Note that if the current object represents a parallel distributed matrix (of type PETScWrappers::MPI::SparseMatrix), then the given vector has to be a distributed vector as well. Conversely, if the matrix is not distributed, then neither may the vector be.

Definition at line 376 of file petsc_matrix_base.cc.

◆ matrix_scalar_product()

PetscScalar PETScWrappers::MatrixBase::matrix_scalar_product ( const VectorBase u,
const VectorBase v 
) const
inherited

Compute the matrix scalar product \(\left(u,Mv\right)\).

The implementation of this function is not as efficient as the one in the MatrixBase class used in deal.II (i.e. the original one, not the PETSc wrapper class) since PETSc doesn't support this operation and needs a temporary vector.

Note that if the current object represents a parallel distributed matrix (of type PETScWrappers::MPI::SparseMatrix), then both vectors have to be distributed vectors as well. Conversely, if the matrix is not distributed, then neither of the vectors may be.

Definition at line 385 of file petsc_matrix_base.cc.

◆ trace()

PetscScalar PETScWrappers::MatrixBase::trace ( ) const
inherited

Return the trace of the matrix, i.e. the sum of all diagonal entries in the matrix.

Definition at line 395 of file petsc_matrix_base.cc.

◆ operator*=()

MatrixBase & PETScWrappers::MatrixBase::operator*= ( const PetscScalar  factor)
inherited

Multiply the entire matrix by a fixed factor.

Definition at line 408 of file petsc_matrix_base.cc.

◆ operator/=()

MatrixBase & PETScWrappers::MatrixBase::operator/= ( const PetscScalar  factor)
inherited

Divide the entire matrix by a fixed factor.

Definition at line 419 of file petsc_matrix_base.cc.

◆ vmult()

void PETScWrappers::MatrixBase::vmult ( VectorBase dst,
const VectorBase src 
) const
inherited

Matrix-vector multiplication: let dst = M*src with M being this matrix.

Source and destination must not be the same vector.

Note that if the current object represents a parallel distributed matrix (of type PETScWrappers::MPI::SparseMatrix), then both vectors have to be distributed vectors as well. Conversely, if the matrix is not distributed, then neither of the vectors may be.

Definition at line 441 of file petsc_matrix_base.cc.

◆ Tvmult()

void PETScWrappers::MatrixBase::Tvmult ( VectorBase dst,
const VectorBase src 
) const
inherited

Matrix-vector multiplication: let dst = MT*src with M being this matrix. This function does the same as vmult() but takes the transposed matrix.

Source and destination must not be the same vector.

Note that if the current object represents a parallel distributed matrix (of type PETScWrappers::MPI::SparseMatrix), then both vectors have to be distributed vectors as well. Conversely, if the matrix is not distributed, then neither of the vectors may be.

Definition at line 452 of file petsc_matrix_base.cc.

◆ vmult_add()

void PETScWrappers::MatrixBase::vmult_add ( VectorBase dst,
const VectorBase src 
) const
inherited

Adding Matrix-vector multiplication. Add M*src on dst with M being this matrix.

Source and destination must not be the same vector.

Note that if the current object represents a parallel distributed matrix (of type PETScWrappers::MPI::SparseMatrix), then both vectors have to be distributed vectors as well. Conversely, if the matrix is not distributed, then neither of the vectors may be.

Definition at line 463 of file petsc_matrix_base.cc.

◆ Tvmult_add()

void PETScWrappers::MatrixBase::Tvmult_add ( VectorBase dst,
const VectorBase src 
) const
inherited

Adding Matrix-vector multiplication. Add MT*src to dst with M being this matrix. This function does the same as vmult_add() but takes the transposed matrix.

Source and destination must not be the same vector.

Note that if the current object represents a parallel distributed matrix (of type PETScWrappers::MPI::SparseMatrix), then both vectors have to be distributed vectors as well. Conversely, if the matrix is not distributed, then neither of the vectors may be.

Definition at line 474 of file petsc_matrix_base.cc.

◆ residual()

PetscScalar PETScWrappers::MatrixBase::residual ( VectorBase dst,
const VectorBase x,
const VectorBase b 
) const
inherited

Compute the residual of an equation Mx=b, where the residual is defined to be r=b-Mx. Write the residual into dst. The l2 norm of the residual vector is returned.

Source x and destination dst must not be the same vector.

Note that if the current object represents a parallel distributed matrix (of type PETScWrappers::MPI::SparseMatrix), then all vectors have to be distributed vectors as well. Conversely, if the matrix is not distributed, then neither of the vectors may be.

Definition at line 574 of file petsc_matrix_base.cc.

◆ begin() [1/2]

const_iterator PETScWrappers::MatrixBase::begin ( ) const
inherited

Iterator starting at the first entry. This can only be called on a processor owning the entire matrix. In all other cases refer to the version of begin() taking a row number as an argument.

◆ begin() [2/2]

const_iterator PETScWrappers::MatrixBase::begin ( const size_type  r) const
inherited

Iterator starting at the first entry of row r.

Note that if the given row is empty, i.e. does not contain any nonzero entries, then the iterator returned by this function equals end(r). Note also that the iterator may not be dereferenceable in that case.

◆ end() [1/2]

const_iterator PETScWrappers::MatrixBase::end ( ) const
inherited

Final iterator. This can only be called on a processor owning the entire matrix. In all other cases refer to the version of end() taking a row number as an argument.

◆ end() [2/2]

const_iterator PETScWrappers::MatrixBase::end ( const size_type  r) const
inherited

Final iterator of row r. It points to the first element past the end of line r, or past the end of the entire sparsity pattern.

Note that the end iterator is not necessarily dereferenceable. This is in particular the case if it is the end iterator for the last row of a matrix.

◆ operator Mat()

PETScWrappers::MatrixBase::operator Mat ( ) const
inherited

Conversion operator to gain access to the underlying PETSc type. If you do this, you cut this class off some information it may need, so this conversion operator should only be used if you know what you do. In particular, it should only be used for read-only operations into the matrix.

Definition at line 590 of file petsc_matrix_base.cc.

◆ petsc_matrix()

Mat & PETScWrappers::MatrixBase::petsc_matrix ( )
inherited

Return a reference to the underlying PETSc type. It can be used to modify the underlying data, so use it only when you know what you are doing.

Definition at line 596 of file petsc_matrix_base.cc.

◆ transpose()

void PETScWrappers::MatrixBase::transpose ( )
inherited

Make an in-place transpose of a matrix.

Definition at line 602 of file petsc_matrix_base.cc.

◆ is_symmetric()

PetscBool PETScWrappers::MatrixBase::is_symmetric ( const double  tolerance = 1.e-12)
inherited

Test whether a matrix is symmetric. Default tolerance is \(1000\times32\)-bit machine precision.

Definition at line 614 of file petsc_matrix_base.cc.

◆ is_hermitian()

PetscBool PETScWrappers::MatrixBase::is_hermitian ( const double  tolerance = 1.e-12)
inherited

Test whether a matrix is Hermitian, i.e. it is the complex conjugate of its transpose. Default tolerance is \(1000\times32\)-bit machine precision.

Definition at line 624 of file petsc_matrix_base.cc.

◆ write_ascii()

void PETScWrappers::MatrixBase::write_ascii ( const PetscViewerFormat  format = PETSC_VIEWER_DEFAULT)
inherited

Print the PETSc matrix object values using PETSc internal matrix viewer function MatView. The default format prints the non- zero matrix elements. For other valid view formats, consult http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Mat/MatView.html

Definition at line 636 of file petsc_matrix_base.cc.

◆ print()

void PETScWrappers::MatrixBase::print ( std::ostream &  out,
const bool  alternative_output = false 
) const
inherited

Print the elements of a matrix to the given output stream.

Parameters
[in,out]outThe output stream to which to write.
[in]alternative_outputThis argument is ignored. It exists for compatibility with similar functions in other matrix classes.

Definition at line 651 of file petsc_matrix_base.cc.

◆ memory_consumption()

std::size_t PETScWrappers::MatrixBase::memory_consumption ( ) const
inherited

Return the number bytes consumed by this matrix on this CPU.

Definition at line 682 of file petsc_matrix_base.cc.

◆ prepare_action()

void PETScWrappers::MatrixBase::prepare_action ( const VectorOperation::values  new_action)
protectedinherited

Ensure that the add/set mode that is required for actions following this call is compatible with the current mode. Should be called from all internal functions accessing matrix elements.

◆ assert_is_compressed()

void PETScWrappers::MatrixBase::assert_is_compressed ( )
protectedinherited

Internal function that checks that there are no pending insert/add operations. Throws an exception otherwise. Useful before calling any PETSc internal functions modifying the matrix.

◆ prepare_add()

void PETScWrappers::MatrixBase::prepare_add ( )
protectedinherited

For some matrix storage formats, in particular for the PETSc distributed blockmatrices, set and add operations on individual elements can not be freely mixed. Rather, one has to synchronize operations when one wants to switch from setting elements to adding to elements. BlockMatrixBase automatically synchronizes the access by calling this helper function for each block. This function ensures that the matrix is in a state that allows adding elements; if it previously already was in this state, the function does nothing.

◆ prepare_set()

void PETScWrappers::MatrixBase::prepare_set ( )
protectedinherited

Same as prepare_add() but prepare the matrix for setting elements if the representation of elements in this class requires such an operation.

◆ mmult() [2/2]

void PETScWrappers::MatrixBase::mmult ( MatrixBase C,
const MatrixBase B,
const VectorBase V 
) const
protectedinherited

Base function to perform the matrix-matrix multiplication \(C = AB\), or, if a vector \(V\) whose size is compatible with B is given, \(C = A \text{diag}(V) B\), where \(\text{diag}(V)\) defines a diagonal matrix with the vector entries.

This function assumes that the calling matrix \(A\) and \(B\) have compatible sizes. The size of \(C\) will be set within this function.

The content as well as the sparsity pattern of the matrix \(C\) will be reset by this function, so make sure that the sparsity pattern is not used somewhere else in your program. This is an expensive operation, so think twice before you use this function.

Definition at line 558 of file petsc_matrix_base.cc.

◆ Tmmult() [2/2]

void PETScWrappers::MatrixBase::Tmmult ( MatrixBase C,
const MatrixBase B,
const VectorBase V 
) const
protectedinherited

Base function to perform the matrix-matrix multiplication with the transpose of this, i.e., \(C = A^T B\), or, if an optional vector \(V\) whose size is compatible with \(B\) is given, \(C = A^T \text{diag}(V) B\), where \(\text{diag}(V)\) defines a diagonal matrix with the vector entries.

This function assumes that the calling matrix \(A\) and \(B\) have compatible sizes. The size of \(C\) will be set within this function.

The content as well as the sparsity pattern of the matrix \(C\) will be changed by this function, so make sure that the sparsity pattern is not used somewhere else in your program. This is an expensive operation, so think twice before you use this function.

Definition at line 566 of file petsc_matrix_base.cc.

◆ subscribe()

void Subscriptor::subscribe ( std::atomic< bool > *const  validity,
const std::string &  identifier = "" 
) const
inherited

Subscribes a user of the object by storing the pointer validity. The subscriber may be identified by text supplied as identifier.

Definition at line 136 of file subscriptor.cc.

◆ unsubscribe()

void Subscriptor::unsubscribe ( std::atomic< bool > *const  validity,
const std::string &  identifier = "" 
) const
inherited

Unsubscribes a user from the object.

Note
The identifier and the validity pointer must be the same as the one supplied to subscribe().

Definition at line 156 of file subscriptor.cc.

◆ n_subscriptions()

unsigned int Subscriptor::n_subscriptions ( ) const
inlineinherited

Return the present number of subscriptions to this object. This allows to use this class for reference counted lifetime determination where the last one to unsubscribe also deletes the object.

Definition at line 301 of file subscriptor.h.

◆ list_subscribers() [1/2]

template<typename StreamType >
void Subscriptor::list_subscribers ( StreamType &  stream) const
inlineinherited

List the subscribers to the input stream.

Definition at line 318 of file subscriptor.h.

◆ list_subscribers() [2/2]

void Subscriptor::list_subscribers ( ) const
inherited

List the subscribers to deallog.

Definition at line 204 of file subscriptor.cc.

◆ serialize()

template<class Archive >
void Subscriptor::serialize ( Archive &  ar,
const unsigned int  version 
)
inlineinherited

Read or write the data of this object to or from a stream for the purpose of serialization using the BOOST serialization library.

This function does not actually serialize any of the member variables of this class. The reason is that what this class stores is only who subscribes to this object, but who does so at the time of storing the contents of this object does not necessarily have anything to do with who subscribes to the object when it is restored. Consequently, we do not want to overwrite the subscribers at the time of restoring, and then there is no reason to write the subscribers out in the first place.

Definition at line 310 of file subscriptor.h.

Friends And Related Function Documentation

◆ BlockMatrixBase< SparseMatrix >

friend class BlockMatrixBase< SparseMatrix >
friend

Definition at line 284 of file petsc_sparse_matrix.h.

Member Data Documentation

◆ matrix

Mat PETScWrappers::MatrixBase::matrix
protectedinherited

A generic matrix object in PETSc. The actual type, a sparse matrix, is set in the constructor.

Definition at line 958 of file petsc_matrix_base.h.

◆ last_action

VectorOperation::values PETScWrappers::MatrixBase::last_action
protectedinherited

Store whether the last action was a write or add operation.

Definition at line 963 of file petsc_matrix_base.h.


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