Reference documentation for deal.II version 9.1.1
PETScWrappers::PreconditionParaSails Class Reference

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

Inheritance diagram for PETScWrappers::PreconditionParaSails:
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## Public Member Functions

PreconditionParaSails ()=default

Public Member Functions inherited from PETScWrappers::PreconditionerBase
PreconditionerBase ()

virtual ~PreconditionerBase ()

void clear ()

void vmult (VectorBase &dst, const VectorBase &src) const

const PC & get_pc () const

## Private Attributes

Protected Member Functions inherited from PETScWrappers::PreconditionerBase
void create_pc ()

operator Mat () const

Protected Attributes inherited from PETScWrappers::PreconditionerBase
PC pc

Mat matrix

## Detailed Description

A class that implements the interface to use the ParaSails sparse approximate inverse preconditioner from the HYPRE suite. Note that PETSc has to be configured with HYPRE (e.g. with –download-hypre=1).

ParaSails uses least-squares minimization to compute a sparse approximate inverse. The sparsity pattern used is the pattern of a power of a sparsified matrix. ParaSails also uses a post-filtering technique to reduce the cost of applying the preconditioner.

ParaSails solves symmetric positive definite (SPD) problems using a factorized SPD preconditioner and can also solve general (nonsymmetric and/or indefinite) problems with a nonfactorized preconditioner. The problem type has to be set in AdditionalData.

The preconditioner does support parallel distributed computations.

Definition at line 812 of file petsc_precondition.h.

## ◆ PreconditionParaSails() [1/2]

 PETScWrappers::PreconditionParaSails::PreconditionParaSails ( )
default

Empty Constructor. You need to call initialize() before using this object.

## ◆ PreconditionParaSails() [2/2]

 PETScWrappers::PreconditionParaSails::PreconditionParaSails ( 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 565 of file petsc_precondition.cc.

## ◆ initialize()

 void PETScWrappers::PreconditionParaSails::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 574 of file petsc_precondition.cc.