Reference documentation for deal.II version Git 98e0067 2016-08-28 17:25:43 -0400

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

Inheritance diagram for SparseDirectUMFPACK:
[legend]

## Public Types

typedef types::global_dof_index size_type

## Public Member Functions

SparseDirectUMFPACK ()

~SparseDirectUMFPACK ()

Setting up a sparse factorization
void initialize (const SparsityPattern &sparsity_pattern)

template<class Matrix >
void factorize (const Matrix &matrix)

template<class Matrix >

Functions that represent the inverse of a matrix
void vmult (Vector< double > &dst, const Vector< double > &src) const

void vmult (BlockVector< double > &dst, const BlockVector< double > &src) const

void Tvmult (Vector< double > &dst, const Vector< double > &src) const

void Tvmult (BlockVector< double > &dst, const BlockVector< double > &src) const

size_type m () const

size_type n () const

Functions that solve linear systems
void solve (Vector< double > &rhs_and_solution, bool transpose=false) const

void solve (BlockVector< double > &rhs_and_solution, bool transpose=false) const

template<class Matrix >
void solve (const Matrix &matrix, Vector< double > &rhs_and_solution, bool transpose=false)

template<class Matrix >
void solve (const Matrix &matrix, BlockVector< double > &rhs_and_solution, bool transpose=false)

Public Member Functions inherited from Subscriptor
Subscriptor ()

Subscriptor (const Subscriptor &)

Subscriptor (Subscriptor &&)

virtual ~Subscriptor ()

Subscriptoroperator= (const Subscriptor &)

Subscriptoroperator= (Subscriptor &&)

void subscribe (const char *identifier=0) const

void unsubscribe (const char *identifier=0) const

unsigned int n_subscriptions () const

void list_subscribers () const

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

## Static Public Member Functions

static::ExceptionBase & ExcUMFPACKError (char *arg1, int arg2)

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

static::ExceptionBase & ExcNoSubscriber (char *arg1, char *arg2)

## Private Member Functions

void clear ()

template<typename number >
void sort_arrays (const SparseMatrixEZ< number > &)

## Private Attributes

size_type _m

size_type _n

void * symbolic_decomposition

std::vector< SuiteSparse_long > Ap

std::vector< double > control

## Detailed Description

This class provides an interface to the sparse direct solver UMFPACK, which is part of the SuiteSparse library (see this link). UMFPACK is a set of routines for solving non-symmetric sparse linear systems, Ax=b, using the Unsymmetric-pattern MultiFrontal method and direct sparse LU factorization. Matrices may have symmetric or unsymmetric sparsity patterns, and may have unsymmetric entries. The use of this class is explained in the step-22 and step-29 tutorial programs.

This matrix class implements the usual interface of preconditioners, that is a function initialize(const SparseMatrix<double>&matrix,const AdditionalData) for initializing and the whole set of vmult() functions common to all matrices. Implemented here are only vmult() and vmult_add(), which perform multiplication with the inverse matrix. Furthermore, this class provides an older interface, consisting of the functions factorize() and solve(). Both interfaces are interchangeable.

Note
This class exists if the UMFPACK interface was not explicitly disabled during configuration.
UMFPACK has its own license, independent of that of deal.II. If you want to use the UMFPACK you have to accept that license. It is linked to from the deal.II ReadMe file. UMFPACK is included courtesy of its author, Timothy A. Davis.

#### Instantiations

There are instantiations of this class for SparseMatrix<double>, SparseMatrix<float>, SparseMatrixEZ<float>, SparseMatrixEZ<double>, BlockSparseMatrix<double>, and BlockSparseMatrix<float>.

Definition at line 82 of file sparse_direct.h.

## Member Typedef Documentation

Declare type for container size.

Definition at line 88 of file sparse_direct.h.

## Constructor & Destructor Documentation

 SparseDirectUMFPACK::SparseDirectUMFPACK ( )

Constructor. See the documentation of this class for the meaning of the parameters to this function.

Definition at line 54 of file sparse_direct.cc.

 SparseDirectUMFPACK::~SparseDirectUMFPACK ( )

Destructor.

Definition at line 40 of file sparse_direct.cc.

## Member Function Documentation

 void SparseDirectUMFPACK::initialize ( const SparsityPattern & sparsity_pattern )

This function does nothing. It is only here to provide a interface consistent with other sparse direct solvers.

Definition at line 48 of file sparse_direct.cc.

template<class Matrix >
 void SparseDirectUMFPACK::factorize ( const Matrix & matrix )

Factorize the matrix. This function may be called multiple times for different matrices, after the object of this class has been initialized for a certain sparsity pattern. You may therefore save some computing time if you want to invert several matrices with the same sparsity pattern. However, note that the bulk of the computing time is actually spent in the factorization, so this functionality may not always be of large benefit.

In contrast to the other direct solver classes, the initialisation method does nothing. Therefore initialise is not automatically called by this method, when the initialization step has not been performed yet.

This function copies the contents of the matrix into its own storage; the matrix can therefore be deleted after this operation, even if subsequent solves are required.

Definition at line 205 of file sparse_direct.cc.

template<class Matrix >
 void SparseDirectUMFPACK::initialize ( const Matrix & matrix, const AdditionalData additional_data = AdditionalData() )

Initialize memory and call SparseDirectUMFPACK::factorize.

Definition at line 428 of file sparse_direct.cc.

 void SparseDirectUMFPACK::vmult ( Vector< double > & dst, const Vector< double > & src ) const

Preconditioner interface function. Usually, given the source vector, this method returns an approximate solution of Ax = b. As this class provides a wrapper to a direct solver, here it is actually the exact solution (exact within the range of numerical accuracy of course).

In other words, this function actually multiplies with the exact inverse of the matrix, $$A^{-1}$$.

Definition at line 436 of file sparse_direct.cc.

 void SparseDirectUMFPACK::vmult ( BlockVector< double > & dst, const BlockVector< double > & src ) const

Same as before, but for block vectors.

Definition at line 447 of file sparse_direct.cc.

 void SparseDirectUMFPACK::Tvmult ( Vector< double > & dst, const Vector< double > & src ) const

Same as before, but uses the transpose of the matrix, i.e. this function multiplies with $$A^{-T}$$.

Definition at line 457 of file sparse_direct.cc.

 void SparseDirectUMFPACK::Tvmult ( BlockVector< double > & dst, const BlockVector< double > & src ) const

Same as before, but for block vectors

Definition at line 468 of file sparse_direct.cc.

 SparseDirectUMFPACK::size_type SparseDirectUMFPACK::m ( ) const

Return the dimension of the codomain (or range) space. To remember: the matrix is of dimension $$m \times n$$.

Definition at line 477 of file sparse_direct.cc.

 SparseDirectUMFPACK::size_type SparseDirectUMFPACK::n ( ) const

Return the dimension of the domain space. To remember: the matrix is of dimension $$m \times n$$.

Definition at line 484 of file sparse_direct.cc.

 void SparseDirectUMFPACK::solve ( Vector< double > & rhs_and_solution, bool transpose = false ) const

Solve for a certain right hand side vector. This function may be called multiple times for different right hand side vectors after the matrix has been factorized. This yields a big saving in computing time, since the actual solution is fast, compared to the factorization of the matrix.

The solution will be returned in place of the right hand side vector.

If the factorization has not happened before, strange things will happen. Note that we can't actually call the factorize() function from here if it has not yet been called, since we have no access to the actual matrix.

If transpose is set to true this function solves for the transpose of the matrix, i.e. $$x=A^{-T}b$$.

Definition at line 301 of file sparse_direct.cc.

 void SparseDirectUMFPACK::solve ( BlockVector< double > & rhs_and_solution, bool transpose = false ) const

Same as before, but for block vectors.

Definition at line 329 of file sparse_direct.cc.

template<class Matrix >
 void SparseDirectUMFPACK::solve ( const Matrix & matrix, Vector< double > & rhs_and_solution, bool transpose = false )

Call the two functions factorize() and solve() in that order, i.e. perform the whole solution process for the given right hand side vector.

The solution will be returned in place of the right hand side vector.

Definition at line 345 of file sparse_direct.cc.

template<class Matrix >
 void SparseDirectUMFPACK::solve ( const Matrix & matrix, BlockVector< double > & rhs_and_solution, bool transpose = false )

Same as before, but for block vectors.

Definition at line 356 of file sparse_direct.cc.

 void SparseDirectUMFPACK::clear ( )
private

Free all memory that hasn't been freed yet.

Definition at line 68 of file sparse_direct.cc.

template<typename number >
 void SparseDirectUMFPACK::sort_arrays ( const SparseMatrixEZ< number > & matrix )
private

Make sure that the arrays Ai and Ap are sorted in each row. UMFPACK wants it this way. We need to have three versions of this function, one for the usual SparseMatrix, one for the SparseMatrixEZ, and one for the BlockSparseMatrix classes

Definition at line 144 of file sparse_direct.cc.

## Member Data Documentation

 size_type SparseDirectUMFPACK::_m
private

The dimension of the range space.

Definition at line 302 of file sparse_direct.h.

 size_type SparseDirectUMFPACK::_n
private

The dimension of the domain space.

Definition at line 307 of file sparse_direct.h.

 void* SparseDirectUMFPACK::symbolic_decomposition
private

The UMFPACK routines allocate objects in which they store information about symbolic and numeric values of the decomposition. The actual data type of these objects is opaque, and only passed around as void pointers.

Definition at line 314 of file sparse_direct.h.

 std::vector SparseDirectUMFPACK::Ap
private

The arrays in which we store the data for the solver. SuiteSparse_long has to be used here for Windows 64 build, if we used only long int, compilation would fail.

Definition at line 342 of file sparse_direct.h.

 std::vector SparseDirectUMFPACK::control
private

Control and info arrays for the solver routines.

Definition at line 349 of file sparse_direct.h.

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