Reference documentation for deal.II version Git 803d21ff95 20201001 11:19:45 0600

#include <deal.II/lac/petsc_precondition.h>
Classes  
struct  AdditionalData 
Public Member Functions  
PreconditionBlockJacobi ()=default  
PreconditionBlockJacobi (const MatrixBase &matrix, const AdditionalData &additional_data=AdditionalData())  
PreconditionBlockJacobi (const MPI_Comm communicator, const AdditionalData &additional_data=AdditionalData())  
void  initialize (const MatrixBase &matrix, const AdditionalData &additional_data=AdditionalData()) 
void  clear () 
void  vmult (VectorBase &dst, const VectorBase &src) const 
void  Tvmult (VectorBase &dst, const VectorBase &src) const 
const PC &  get_pc () const 
Protected Member Functions  
void  initialize () 
void  create_pc () 
operator Mat () const  
Protected Attributes  
AdditionalData  additional_data 
PC  pc 
Mat  matrix 
A class that implements the interface to use the PETSc Block Jacobi preconditioner. PETSc defines the term "block Jacobi" as a preconditioner in which it looks at a number of diagonal blocks of the matrix and then defines a preconditioner in which the preconditioner matrix has the same block structure as only these diagonal blocks, and each diagonal block of the preconditioner is an approximation of the inverse of the corresponding block of the original matrix. The blocking structure of the matrix is determined by the association of degrees of freedom to the individual processors in an MPIparallel job. If you use this preconditioner on a sequential job (or an MPI job with only one process) then the entire matrix is the only block.
By default, PETSc uses an ILU(0) decomposition of each diagonal block of the matrix for preconditioning. This can be changed, as is explained in the relevant section of the PETSc manual, but is not implemented here.
See the comment in the base class PreconditionerBase for when this preconditioner may or may not work.
Definition at line 220 of file petsc_precondition.h.

default 
Empty Constructor. You need to call initialize() before using this object.
PreconditionBlockJacobi< MatrixType, inverse_type >::PreconditionBlockJacobi  (  const MatrixBase &  matrix, 
const AdditionalData &  additional_data = AdditionalData() 

) 
Constructor. Take the matrix which is used to form the preconditioner, and additional flags if there are any.
Definition at line 189 of file petsc_precondition.cc.
PreconditionBlockJacobi< MatrixType, inverse_type >::PreconditionBlockJacobi  (  const MPI_Comm  communicator, 
const AdditionalData &  additional_data = AdditionalData() 

) 
Same as above but without setting a matrix to form the preconditioner. Intended to be used with SLEPc objects.
Definition at line 175 of file petsc_precondition.cc.
void PreconditionBlockJacobi< MatrixType, inverse_type >::initialize  (  const MatrixBase &  matrix, 
const AdditionalData &  additional_data = AdditionalData() 

) 
Initialize the preconditioner object and calculate all data that is necessary for applying it in a solver. This function is automatically called when calling the constructor with the same arguments and is only used if you create the preconditioner without arguments.
Definition at line 208 of file petsc_precondition.cc.

protected 
Initialize the preconditioner object without knowing a particular matrix. This function sets up appropriate parameters to the underlying PETSc object after it has been created.
Definition at line 197 of file petsc_precondition.cc.

inherited 
Destroys the preconditioner, leaving an object like just after having called the constructor.
Definition at line 52 of file petsc_precondition.cc.

inherited 
Apply the preconditioner once to the given src vector.
Definition at line 66 of file petsc_precondition.cc.

inherited 
Apply the transpose preconditioner once to the given src vector.
Definition at line 76 of file petsc_precondition.cc.

inherited 
Give access to the underlying PETSc object.
Definition at line 113 of file petsc_precondition.cc.

protectedinherited 
Internal function to create the PETSc preconditioner object. Fails if called twice.
Definition at line 86 of file petsc_precondition.cc.

protectedinherited 
Conversion operator to get a representation of the matrix that represents this preconditioner. We use this inside the actual solver, where we need to pass this matrix to the PETSc solvers.
Definition at line 119 of file petsc_precondition.cc.

protected 
Store a copy of the flags for this particular preconditioner.
Definition at line 267 of file petsc_precondition.h.

protectedinherited 
the PETSc preconditioner object
Definition at line 99 of file petsc_precondition.h.

protectedinherited 
A pointer to the matrix that acts as a preconditioner.
Definition at line 104 of file petsc_precondition.h.