PETScMatrix.h¶

Note

The documentation on this page was automatically extracted from the DOLFIN C++ code and may need to be edited or expanded.

class PETScMatrix¶

Parent class(es)

GenericMatrix

PETScBaseMatrix

This class provides a simple matrix class based on PETSc. It is a wrapper for a PETSc matrix pointer (Mat) implementing the GenericMatrix interface.

The interface is intentionally simple. For advanced usage, access the PETSc Mat pointer using the function mat() and use the standard PETSc interface.

PETScMatrix()¶: Create empty matrix (on MPI_COMM_WORLD)

explicit PETScMatrix(MPI_Comm comm)¶: Create empty matrix

explicit PETScMatrix(Mat A)¶: Create a wrapper around a PETSc Mat pointer. The Mat object should have been created, e.g. via PETSc MatrCreate.

PETScMatrix(const PETScMatrix &A)¶: Copy constructor

void init(const TensorLayout &tensor_layout)¶: Initialize zero tensor using tensor layout

bool empty() const¶: Return true if empty

std::size_t size(std::size_t dim) const¶: Return size of given dimension

std::pair<std::int64_t, std::int64_t> local_range(std::size_t dim) const¶: Return local ownership range

std::size_t nnz() const¶: Return number of non-zero entries in matrix (collective)

void zero()¶: Set all entries to zero and keep any sparse structure

void apply(std::string mode)¶: Finalize assembly of tensor. The following values are recognized for the mode parameter:

add - corresponds to PETSc MatAssemblyBegin+End(MAT_FINAL_ASSEMBLY) insert - corresponds to PETSc MatAssemblyBegin+End(MAT_FINAL_ASSEMBLY) flush - corresponds to PETSc MatAssemblyBegin+End(MAT_FLUSH_ASSEMBLY)

MPI_Comm mpi_comm() const¶: Return MPI communicator

std::string str(bool verbose) const¶: Return informal string representation (pretty-print)

std::shared_ptr<GenericMatrix> copy() const¶: Return copy of matrix

void init_vector(GenericVector &z, std::size_t dim) const¶

Initialize vector z to be compatible with the matrix-vector product y = Ax. In the parallel case, both size and layout are important.

Arguments

dim (std::size_t): The dimension (axis): dim = 0 –> z = y, dim = 1 –> z = x

void get(double *block, std::size_t m, const dolfin::la_index *rows, std::size_t n, const dolfin::la_index *cols) const¶: Get block of values

void set(const double *block, std::size_t m, const dolfin::la_index *rows, std::size_t n, const dolfin::la_index *cols)¶: Set block of values using global indices

void set_local(const double *block, std::size_t m, const dolfin::la_index *rows, std::size_t n, const dolfin::la_index *cols)¶: Set block of values using local indices

void add(const double *block, std::size_t m, const dolfin::la_index *rows, std::size_t n, const dolfin::la_index *cols)¶: Add block of values using global indices

void add_local(const double *block, std::size_t m, const dolfin::la_index *rows, std::size_t n, const dolfin::la_index *cols)¶: Add block of values using local indices

void axpy(double a, const GenericMatrix &A, bool same_nonzero_pattern)¶: Add multiple of given matrix (AXPY operation)

double norm(std::string norm_type) const¶: Return norm of matrix

void getrow(std::size_t row, std::vector<std::size_t> &columns, std::vector<double> &values) const¶: Get non-zero values of given row

void setrow(std::size_t row, const std::vector<std::size_t> &columns, const std::vector<double> &values)¶: Set values for given row

void zero(std::size_t m, const dolfin::la_index *rows)¶: Set given rows (global row indices) to zero

void zero_local(std::size_t m, const dolfin::la_index *rows)¶: Set given rows (local row indices) to zero

void ident(std::size_t m, const dolfin::la_index *rows)¶: Set given rows (global row indices) to identity matrix

void ident_local(std::size_t m, const dolfin::la_index *rows)¶: Set given rows (local row indices) to identity matrix

void get_diagonal(GenericVector &x) const¶: Get diagonal of a matrix

void set_diagonal(const GenericVector &x)¶: Set diagonal of a matrix

const PETScMatrix &operator*=(double a)¶: Multiply matrix by given number

const PETScMatrix &operator/=(double a)¶: Divide matrix by given number

const GenericMatrix &operator=(const GenericMatrix &A)¶: Assignment operator

bool is_symmetric(double tol) const¶: Test if matrix is symmetric

GenericLinearAlgebraFactory &factory() const¶: Return linear algebra backend factory

void set_options_prefix(std::string options_prefix)¶: Sets the prefix used by PETSc when searching the options database

std::string get_options_prefix() const¶: Returns the prefix used by PETSc when searching the options database

void set_from_options()¶: Call PETSc function MatSetFromOptions on the PETSc Mat object

const PETScMatrix &operator=(const PETScMatrix &A)¶: Assignment operator

void set_nullspace(const VectorSpaceBasis &nullspace)¶: Attach nullspace to matrix (typically used by Krylov solvers when solving singular systems)

void set_near_nullspace(const VectorSpaceBasis &nullspace)¶: Attach near nullspace to matrix (used by preconditioners, such as smoothed aggregation algerbraic multigrid)

void binary_dump(std::string file_name) const¶: Dump matrix to PETSc binary format