Reference documentation for deal.II version Git 6fa7894 2017-12-12 13:14:59 +0100
LAPACKFullMatrix< number > Class Template Reference

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

Inheritance diagram for LAPACKFullMatrix< number >:
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## Public Types

typedef types::global_dof_index size_type

Public Types inherited from TransposeTable< number >
typedef TableBase< 2, number >::size_type size_type

Public Types inherited from TableBase< 2, number >
typedef AlignedVector< number >::size_type size_type

## Public Member Functions

LAPACKFullMatrix (const size_type size=0)

LAPACKFullMatrix (const size_type rows, const size_type cols)

LAPACKFullMatrix (const LAPACKFullMatrix &)

LAPACKFullMatrix< number > & operator= (const LAPACKFullMatrix< number > &)

template<typename number2 >
LAPACKFullMatrix< number > & operator= (const FullMatrix< number2 > &)

template<typename number2 >
LAPACKFullMatrix< number > & operator= (const SparseMatrix< number2 > &)

LAPACKFullMatrix< number > & operator= (const number d)

LAPACKFullMatrix< number > & operator*= (const number factor)

LAPACKFullMatrix< number > & operator/= (const number factor)

void add (const number a, const LAPACKFullMatrix< number > &A)

template<typename MatrixType >
void copy_from (const MatrixType &)

void reinit (const size_type size)

void reinit (const size_type rows, const size_type cols)

void set_property (const LAPACKSupport::Property property)

unsigned int m () const

unsigned int n () const

template<typename MatrixType >
void fill (const MatrixType &src, const size_type dst_offset_i=0, const size_type dst_offset_j=0, const size_type src_offset_i=0, const size_type src_offset_j=0, const number factor=1., const bool transpose=false)

template<typename number2 >
void vmult (Vector< number2 > &w, const Vector< number2 > &v, const bool adding=false) const

void vmult (Vector< number > &w, const Vector< number > &v, const bool adding=false) const

template<typename number2 >
void vmult_add (Vector< number2 > &w, const Vector< number2 > &v) const

void vmult_add (Vector< number > &w, const Vector< number > &v) const

template<typename number2 >
void Tvmult (Vector< number2 > &w, const Vector< number2 > &v, const bool adding=false) const

void Tvmult (Vector< number > &w, const Vector< number > &v, const bool adding=false) const

template<typename number2 >
void Tvmult_add (Vector< number2 > &w, const Vector< number2 > &v) const

void Tvmult_add (Vector< number > &w, const Vector< number > &v) const

void mmult (LAPACKFullMatrix< number > &C, const LAPACKFullMatrix< number > &B, const bool adding=false) const

void mmult (FullMatrix< number > &C, const LAPACKFullMatrix< number > &B, const bool adding=false) const

void Tmmult (LAPACKFullMatrix< number > &C, const LAPACKFullMatrix< number > &B, const bool adding=false) const

void Tmmult (FullMatrix< number > &C, const LAPACKFullMatrix< number > &B, const bool adding=false) const

void mTmult (LAPACKFullMatrix< number > &C, const LAPACKFullMatrix< number > &B, const bool adding=false) const

void mTmult (FullMatrix< number > &C, const LAPACKFullMatrix< number > &B, const bool adding=false) const

void TmTmult (LAPACKFullMatrix< number > &C, const LAPACKFullMatrix< number > &B, const bool adding=false) const

void TmTmult (FullMatrix< number > &C, const LAPACKFullMatrix< number > &B, const bool adding=false) const

void compute_lu_factorization ()

void compute_cholesky_factorization ()

number reciprocal_condition_number (const number l1_norm) const

number reciprocal_condition_number () const

number determinant () const

number l1_norm () const

number linfty_norm () const

number frobenius_norm () const

number trace () const

void invert ()

void solve (Vector< number > &v, const bool transposed=false) const

void solve (LAPACKFullMatrix< number > &B, const bool transposed=false) const

void apply_lu_factorization (Vector< number > &v, const bool transposed) const

void apply_lu_factorization (LAPACKFullMatrix< number > &B, const bool transposed) const

void compute_eigenvalues (const bool right_eigenvectors=false, const bool left_eigenvectors=false)

void compute_eigenvalues_symmetric (const number lower_bound, const number upper_bound, const number abs_accuracy, Vector< number > &eigenvalues, FullMatrix< number > &eigenvectors)

void compute_generalized_eigenvalues_symmetric (LAPACKFullMatrix< number > &B, const number lower_bound, const number upper_bound, const number abs_accuracy, Vector< number > &eigenvalues, std::vector< Vector< number > > &eigenvectors, const int itype=1)

void compute_generalized_eigenvalues_symmetric (LAPACKFullMatrix< number > &B, std::vector< Vector< number > > &eigenvectors, const int itype=1)

void compute_svd ()

void compute_inverse_svd (const double threshold=0.)

std::complex< number > eigenvalue (const size_type i) const

number singular_value (const size_type i) const

void print_formatted (std::ostream &out, const unsigned int precision=3, const bool scientific=true, const unsigned int width=0, const char *zero_string=" ", const double denominator=1., const double threshold=0.) const

Public Member Functions inherited from TransposeTable< number >
TransposeTable ()=default

TransposeTable (const unsigned int size1, const unsigned int size2)

void reinit (const unsigned int size1, const unsigned int size2, const bool omit_default_initialization=false)

AlignedVector< number >::const_reference operator() (const unsigned int i, const unsigned int j) const

AlignedVector< number >::reference operator() (const unsigned int i, const unsigned int j)

unsigned int n_rows () const

unsigned int n_cols () const

Public Member Functions inherited from TableBase< 2, number >
TableBase ()=default

TableBase (const TableIndices< N > &sizes)

TableBase (const TableIndices< N > &sizes, InputIterator entries, const bool C_style_indexing=true)

TableBase (const TableBase< N, number > &src)

TableBase (const TableBase< N, T2 > &src)

TableBase (TableBase< N, number > &&src)

~TableBase ()=default

TableBase< N, number > & operator= (const TableBase< N, number > &src)

TableBase< N, number > & operator= (const TableBase< N, T2 > &src)

TableBase< N, number > & operator= (TableBase< N, number > &&src)

bool operator== (const TableBase< N, number > &T2) const

void reset_values ()

void reinit (const TableIndices< N > &new_size, const bool omit_default_initialization=false)

unsigned int size (const unsigned int i) const

const TableIndices< N > & size () const

size_type n_elements () const

bool empty () const

void fill (InputIterator entries, const bool C_style_indexing=true)

void fill (const number &value)

AlignedVector< number >::reference operator() (const TableIndices< N > &indices)

AlignedVector< number >::const_reference operator() (const TableIndices< N > &indices) const

void swap (TableBase< N, number > &v)

std::size_t memory_consumption () const

void serialize (Archive &ar, const unsigned int version)

Public Member Functions inherited from Subscriptor
Subscriptor ()

Subscriptor (const Subscriptor &)

Subscriptor (Subscriptor &&)

virtual ~Subscriptor ()

Subscriptoroperator= (const Subscriptor &)

Subscriptoroperator= (Subscriptor &&)

void subscribe (const char *identifier=nullptr) const

void unsubscribe (const char *identifier=nullptr) const

unsigned int n_subscriptions () const

void list_subscribers () const

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

## Private Member Functions

number norm (const char type) const

## Private Attributes

LAPACKSupport::State state

LAPACKSupport::Property property

std::vector< number > work

std::vector< int > iwork

std::vector< int > ipiv

std::vector< number > inv_work

std::vector< number > wr

std::vector< number > wi

std::vector< number > vl

std::vector< number > vr

std::shared_ptr< LAPACKFullMatrix< number > > svd_u

std::shared_ptr< LAPACKFullMatrix< number > > svd_vt

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

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

Protected Member Functions inherited from TransposeTable< number >
AlignedVector< number >::reference el (const unsigned int i, const unsigned int j)

AlignedVector< number >::const_reference el (const unsigned int i, const unsigned int j) const

Protected Member Functions inherited from TableBase< 2, number >
size_type position (const TableIndices< N > &indices) const

AlignedVector< number >::reference el (const TableIndices< N > &indices)

AlignedVector< number >::const_reference el (const TableIndices< N > &indices) const

Protected Attributes inherited from TableBase< 2, number >
AlignedVector< number > values

TableIndices< N > table_size

## Detailed Description

### template<typename number> class LAPACKFullMatrix< number >

A variant of FullMatrix using LAPACK functions wherever possible. In order to do this, the matrix is stored in transposed order. The element access functions hide this fact by reverting the transposition.

Note
In order to perform LAPACK functions, the class contains a lot of auxiliary data in the private section. The names of these data vectors are usually the names chosen for the arguments in the LAPACK documentation.

Definition at line 61 of file mpi.h.

## Member Typedef Documentation

template<typename number>
 typedef types::global_dof_index LAPACKFullMatrix< number >::size_type

Declare type for container size.

Definition at line 60 of file lapack_full_matrix.h.

## Constructor & Destructor Documentation

template<typename number >
 LAPACKFullMatrix< number >::LAPACKFullMatrix ( const size_type size = 0 )
explicit

Constructor. Initialize the matrix as a square matrix with dimension n.

In order to avoid the implicit conversion of integers and other types to a matrix, this constructor is declared explicit.

By default, no memory is allocated.

Definition at line 33 of file lapack_full_matrix.cc.

template<typename number >
 LAPACKFullMatrix< number >::LAPACKFullMatrix ( const size_type rows, const size_type cols )

Constructor. Initialize the matrix as a rectangular matrix.

Definition at line 42 of file lapack_full_matrix.cc.

template<typename number >
 LAPACKFullMatrix< number >::LAPACKFullMatrix ( const LAPACKFullMatrix< number > & M )

Copy constructor. This constructor does a deep copy of the matrix. Therefore, it poses a possible efficiency problem, if for example, function arguments are passed by value rather than by reference. Unfortunately, we can't mark this copy constructor explicit, since that prevents the use of this class in containers, such as std::vector. The responsibility to check performance of programs must therefore remain with the user of this class.

Definition at line 52 of file lapack_full_matrix.cc.

## Member Function Documentation

template<typename number>
 LAPACKFullMatrix< number > & LAPACKFullMatrix< number >::operator= ( const LAPACKFullMatrix< number > & M )

Assignment operator.

Definition at line 62 of file lapack_full_matrix.cc.

template<typename number >
template<typename number2 >
 LAPACKFullMatrix< number > & LAPACKFullMatrix< number >::operator= ( const FullMatrix< number2 > & M )

Assignment operator from a regular FullMatrix.

Note
Since LAPACK expects matrices in transposed order, this transposition is included here.

Definition at line 93 of file lapack_full_matrix.cc.

template<typename number >
template<typename number2 >
 LAPACKFullMatrix< number > & LAPACKFullMatrix< number >::operator= ( const SparseMatrix< number2 > & M )

Assignment operator from a regular SparseMatrix.

Note
Since LAPACK expects matrices in transposed order, this transposition is included here.

Definition at line 110 of file lapack_full_matrix.cc.

template<typename number>
 LAPACKFullMatrix< number > & LAPACKFullMatrix< number >::operator= ( const number d )

This operator assigns a scalar to a matrix. To avoid confusion with constructors, zero (when cast to the number type) is the only value allowed for d

Definition at line 126 of file lapack_full_matrix.cc.

template<typename number>
 LAPACKFullMatrix< number > & LAPACKFullMatrix< number >::operator*= ( const number factor )

This operator multiplies all entries by a fixed factor.

Definition at line 141 of file lapack_full_matrix.cc.

template<typename number>
 LAPACKFullMatrix< number > & LAPACKFullMatrix< number >::operator/= ( const number factor )

This operator divides all entries by a fixed factor.

Definition at line 157 of file lapack_full_matrix.cc.

template<typename number>
 void LAPACKFullMatrix< number >::add ( const number a, const LAPACKFullMatrix< number > & A )

Simple addition of a scaled matrix, i.e. *this += a*A.

Definition at line 177 of file lapack_full_matrix.cc.

template<typename number >
template<typename MatrixType >
 void LAPACKFullMatrix< number >::copy_from ( const MatrixType & M )
inline

Assignment from different matrix classes, performing the usual conversion to the transposed format expected by LAPACK. This assignment operator uses iterators of the typename MatrixType. Therefore, sparse matrices are possible sources.

Definition at line 837 of file lapack_full_matrix.h.

template<typename number >
 void LAPACKFullMatrix< number >::reinit ( const size_type size )

Regenerate the current matrix by one that has the same properties as if it were created by the constructor of this class with the same argument list as this present function.

Definition at line 73 of file lapack_full_matrix.cc.

template<typename number >
 void LAPACKFullMatrix< number >::reinit ( const size_type rows, const size_type cols )

Regenerate the current matrix by one that has the same properties as if it were created by the constructor of this class with the same argument list as this present function.

Definition at line 82 of file lapack_full_matrix.cc.

template<typename number >
 void LAPACKFullMatrix< number >::set_property ( const LAPACKSupport::Property property )

Assign property to this matrix.

Definition at line 611 of file lapack_full_matrix.cc.

template<typename number >
 unsigned int LAPACKFullMatrix< number >::m ( ) const
inline

Return the dimension of the codomain (or range) space.

Note
The matrix is of dimension $$m \times n$$.

Definition at line 821 of file lapack_full_matrix.h.

template<typename number >
 unsigned int LAPACKFullMatrix< number >::n ( ) const
inline

Return the dimension of the domain space.

Note
The matrix is of dimension $$m \times n$$.

Definition at line 829 of file lapack_full_matrix.h.

template<typename number>
template<typename MatrixType >
 void LAPACKFullMatrix< number >::fill ( const MatrixType & src, const size_type dst_offset_i = 0, const size_type dst_offset_j = 0, const size_type src_offset_i = 0, const size_type src_offset_j = 0, const number factor = 1., const bool transpose = false )
inline

Fill rectangular block.

A rectangular block of the matrix src is copied into this. The upper left corner of the block being copied is (src_offset_i,src_offset_j). The upper left corner of the copied block is (dst_offset_i,dst_offset_j). The size of the rectangular block being copied is the maximum size possible, determined either by the size of this or src.

The final two arguments allow to enter a multiple of the source or its transpose.

Definition at line 860 of file lapack_full_matrix.h.

template<typename number >
template<typename number2 >
 void LAPACKFullMatrix< number >::vmult ( Vector< number2 > & w, const Vector< number2 > & v, const bool adding = false ) const

Matrix-vector-multiplication.

Depending on previous transformations recorded in state, the result of this function is one of

The optional parameter adding determines, whether the result is stored in w or added to w.

Note
Source and destination must not be the same vector.
The template with number2 only exists for compile-time compatibility with FullMatrix. Only the case number2 = number is implemented due to limitations in the underlying LAPACK interface. All other variants throw an error upon invocation.

Definition at line 893 of file lapack_full_matrix.h.

template<typename number>
 void LAPACKFullMatrix< number >::vmult ( Vector< number > & w, const Vector< number > & v, const bool adding = false ) const

Specialization of above function for compatible Vector::value_type.

Definition at line 198 of file lapack_full_matrix.cc.

template<typename number >
template<typename number2 >
 void LAPACKFullMatrix< number >::vmult_add ( Vector< number2 > & w, const Vector< number2 > & v ) const

See the documentation of vmult() for details on the implementation.

Definition at line 906 of file lapack_full_matrix.h.

template<typename number>
 void LAPACKFullMatrix< number >::vmult_add ( Vector< number > & w, const Vector< number > & v ) const

Specialization of above function for compatible Vector::value_type.

Definition at line 379 of file lapack_full_matrix.cc.

template<typename number >
template<typename number2 >
 void LAPACKFullMatrix< number >::Tvmult ( Vector< number2 > & w, const Vector< number2 > & v, const bool adding = false ) const

Transpose matrix-vector-multiplication.

The optional parameter adding determines, whether the result is stored in w or added to w.

See the documentation of vmult() for details on the implementation.

Definition at line 918 of file lapack_full_matrix.h.

template<typename number>
 void LAPACKFullMatrix< number >::Tvmult ( Vector< number > & w, const Vector< number > & v, const bool adding = false ) const

Specialization of above function for compatible Vector::value_type.

Definition at line 287 of file lapack_full_matrix.cc.

template<typename number >
template<typename number2 >
 void LAPACKFullMatrix< number >::Tvmult_add ( Vector< number2 > & w, const Vector< number2 > & v ) const

Adding transpose matrix-vector-multiplication. w += AT*v

See the documentation of vmult() for details on the implementation.

Definition at line 931 of file lapack_full_matrix.h.

template<typename number>
 void LAPACKFullMatrix< number >::Tvmult_add ( Vector< number > & w, const Vector< number > & v ) const

Specialization of above function for compatible Vector::value_type.

Definition at line 388 of file lapack_full_matrix.cc.

template<typename number>
 void LAPACKFullMatrix< number >::mmult ( LAPACKFullMatrix< number > & C, const LAPACKFullMatrix< number > & B, const bool adding = false ) const

Matrix-matrix-multiplication.

The optional parameter adding determines, whether the result is stored in C or added to C.

Assumes that A and B have compatible sizes and that C already has the right size.

This function uses the BLAS function Xgemm.

Definition at line 397 of file lapack_full_matrix.cc.

template<typename number>
 void LAPACKFullMatrix< number >::mmult ( FullMatrix< number > & C, const LAPACKFullMatrix< number > & B, const bool adding = false ) const

Same as before, but stores the result in a FullMatrix, not in a LAPACKFullMatrix.

Definition at line 420 of file lapack_full_matrix.cc.

template<typename number>
 void LAPACKFullMatrix< number >::Tmmult ( LAPACKFullMatrix< number > & C, const LAPACKFullMatrix< number > & B, const bool adding = false ) const

Matrix-matrix-multiplication using transpose of this.

The optional parameter adding determines, whether the result is stored in C or added to C.

Assumes that A and B have compatible sizes and that C already has the right size.

This function uses the BLAS function Xgemm.

Definition at line 445 of file lapack_full_matrix.cc.

template<typename number>
 void LAPACKFullMatrix< number >::Tmmult ( FullMatrix< number > & C, const LAPACKFullMatrix< number > & B, const bool adding = false ) const

Same as before, but stores the result in a FullMatrix, not in a LAPACKFullMatrix.

Definition at line 468 of file lapack_full_matrix.cc.

template<typename number>
 void LAPACKFullMatrix< number >::mTmult ( LAPACKFullMatrix< number > & C, const LAPACKFullMatrix< number > & B, const bool adding = false ) const

Matrix-matrix-multiplication using transpose of B.

The optional parameter adding determines, whether the result is stored in C or added to C.

Assumes that A and B have compatible sizes and that C already has the right size.

This function uses the BLAS function Xgemm.

Definition at line 492 of file lapack_full_matrix.cc.

template<typename number>
 void LAPACKFullMatrix< number >::mTmult ( FullMatrix< number > & C, const LAPACKFullMatrix< number > & B, const bool adding = false ) const

Same as before, but stores the result in a FullMatrix, not in a LAPACKFullMatrix.

Definition at line 516 of file lapack_full_matrix.cc.

template<typename number>
 void LAPACKFullMatrix< number >::TmTmult ( LAPACKFullMatrix< number > & C, const LAPACKFullMatrix< number > & B, const bool adding = false ) const

Matrix-matrix-multiplication using transpose of this and B.

The optional parameter adding determines, whether the result is stored in C or added to C.

Assumes that A and B have compatible sizes and that C already has the right size.

This function uses the BLAS function Xgemm.

Definition at line 540 of file lapack_full_matrix.cc.

template<typename number>
 void LAPACKFullMatrix< number >::TmTmult ( FullMatrix< number > & C, const LAPACKFullMatrix< number > & B, const bool adding = false ) const

Same as before, but stores the result in a FullMatrix, not in a LAPACKFullMatrix.

Definition at line 563 of file lapack_full_matrix.cc.

template<typename number >
 void LAPACKFullMatrix< number >::compute_lu_factorization ( )

Compute the LU factorization of the matrix using LAPACK function Xgetrf.

Definition at line 587 of file lapack_full_matrix.cc.

template<typename number >
 void LAPACKFullMatrix< number >::compute_cholesky_factorization ( )

Compute the Cholesky factorization of the matrix using LAPACK function Xpotrf.

Note
The factorization is stored in the lower-triangular part of the matrix.

Definition at line 699 of file lapack_full_matrix.cc.

template<typename number>
 number LAPACKFullMatrix< number >::reciprocal_condition_number ( const number l1_norm ) const

Estimate the reciprocal of the condition number $$1/k(A)$$ in $$L_1$$ norm ( $$1/(||A||_1 ||A^{-1}||_1)$$) of a symmetric positive definite matrix using Cholesky factorization. This function can only be called if the matrix is already factorized.

Note
The condition number $$k(A)$$ can be used to estimate the numerical error related to the matrix inversion or the solution of the system of linear algebraic equations as error = std::numeric_limits<Number>::epsilon * k. Alternatively one can get the number of accurate digits std::floor(std::log10(k)).
The function computes reciprocal of the condition number to avoid possible overflow if the matrix is nearly singular.
Parameters
 [in] l1_norm Is the $$L_1$$ norm of the matrix before calling Cholesky factorization. It can be obtained by calling l1_norm().

Definition at line 726 of file lapack_full_matrix.cc.

template<typename number>
 number LAPACKFullMatrix< number >::reciprocal_condition_number ( ) const

Estimate the reciprocal of the condition number $$1/k(A)$$ in $$L_1$$ norm for triangular matrices. The matrix has to have the LAPACKSupport::Property set to either LAPACKSupport::Property::upper_triangular or LAPACKSupport::Property::lower_triangular, see set_property().

Definition at line 753 of file lapack_full_matrix.cc.

template<typename number >
 number LAPACKFullMatrix< number >::determinant ( ) const

Compute the determinant of a matrix. As it requires the LU factorization of the matrix, this function can only be called after compute_lu_factorization() has been called.

Definition at line 1010 of file lapack_full_matrix.cc.

template<typename number >
 number LAPACKFullMatrix< number >::l1_norm ( ) const

Compute $$L_1$$ norm.

Definition at line 619 of file lapack_full_matrix.cc.

template<typename number >
 number LAPACKFullMatrix< number >::linfty_norm ( ) const

Compute $$L_\infty$$ norm.

Definition at line 628 of file lapack_full_matrix.cc.

template<typename number >
 number LAPACKFullMatrix< number >::frobenius_norm ( ) const

Compute Frobenius norm

Definition at line 637 of file lapack_full_matrix.cc.

template<typename number >
 number LAPACKFullMatrix< number >::trace ( ) const

Compute trace of the matrix, i.e. the sum of the diagonal values. Obviously, the matrix needs to be quadratic for this function.

Definition at line 680 of file lapack_full_matrix.cc.

template<typename number >
 void LAPACKFullMatrix< number >::invert ( )

Invert the matrix by first computing an LU/Cholesky factorization with the LAPACK function Xgetrf/Xpotrf and then building the actual inverse using Xgetri/Xpotri.

Definition at line 851 of file lapack_full_matrix.cc.

template<typename number>
 void LAPACKFullMatrix< number >::solve ( Vector< number > & v, const bool transposed = false ) const

Solve the linear system with right hand side v and put the solution back to v. The matrix should be either triangular or LU/Cholesky factorization should be previously computed.

The flag transposed indicates whether the solution of the transposed system is to be performed.

Definition at line 894 of file lapack_full_matrix.cc.

template<typename number>
 void LAPACKFullMatrix< number >::solve ( LAPACKFullMatrix< number > & B, const bool transposed = false ) const

Same as above but for multiple right hand sides (as many as there are columns in the matrix B).

Definition at line 941 of file lapack_full_matrix.cc.

template<typename number>
 void LAPACKFullMatrix< number >::apply_lu_factorization ( Vector< number > & v, const bool transposed ) const

Solve the linear system with right hand side given by applying forward/backward substitution to the previously computed LU factorization. Uses LAPACK function Xgetrs.

The flag transposed indicates whether the solution of the transposed system is to be performed.

Deprecated:

Definition at line 990 of file lapack_full_matrix.cc.

template<typename number>
 void LAPACKFullMatrix< number >::apply_lu_factorization ( LAPACKFullMatrix< number > & B, const bool transposed ) const

Solve the linear system with multiple right hand sides (as many as there are columns in the matrix b) given by applying forward/backward substitution to the previously computed LU factorization. Uses LAPACK function Xgetrs.

The flag transposed indicates whether the solution of the transposed system is to be performed.

Deprecated:

Definition at line 1000 of file lapack_full_matrix.cc.

template<typename number >
 void LAPACKFullMatrix< number >::compute_eigenvalues ( const bool right_eigenvectors = false, const bool left_eigenvectors = false )

Compute eigenvalues of the matrix. After this routine has been called, eigenvalues can be retrieved using the eigenvalue() function. The matrix itself will be LAPACKSupport::unusable after this operation.

The optional arguments allow to compute left and right eigenvectors as well.

Note that the function does not return the computed eigenvalues right away since that involves copying data around between the output arrays of the LAPACK functions and any return array. This is often unnecessary since one may not be interested in all eigenvalues at once, but for example only the extreme ones. In that case, it is cheaper to just have this function compute the eigenvalues and have a separate function that returns whatever eigenvalue is requested.

Note
Calls the LAPACK function Xgeev.

Definition at line 1040 of file lapack_full_matrix.cc.

template<typename number>
 void LAPACKFullMatrix< number >::compute_eigenvalues_symmetric ( const number lower_bound, const number upper_bound, const number abs_accuracy, Vector< number > & eigenvalues, FullMatrix< number > & eigenvectors )

Compute eigenvalues and eigenvectors of a real symmetric matrix. Only eigenvalues in the interval (lower_bound, upper_bound] are computed with the absolute tolerance abs_accuracy. An approximate eigenvalue is accepted as converged when it is determined to lie in an interval [a,b] of width less than or equal to abs_accuracy + eps * max( |a|,|b| ), where eps is the machine precision. If abs_accuracy is less than or equal to zero, then eps*|t| will be used in its place, where |t| is the 1-norm of the tridiagonal matrix obtained by reducing A to tridiagonal form. Eigenvalues will be computed most accurately when abs_accuracy is set to twice the underflow threshold, not zero. After this routine has been called, all eigenvalues in (lower_bound, upper_bound] will be stored in eigenvalues and the corresponding eigenvectors will be stored in the columns of eigenvectors, whose dimension is set accordingly.

Note
Calls the LAPACK function Xsyevx. For this to work, deal.II must be configured to use LAPACK.

Definition at line 1101 of file lapack_full_matrix.cc.

template<typename number>
 void LAPACKFullMatrix< number >::compute_generalized_eigenvalues_symmetric ( LAPACKFullMatrix< number > & B, const number lower_bound, const number upper_bound, const number abs_accuracy, Vector< number > & eigenvalues, std::vector< Vector< number > > & eigenvectors, const int itype = 1 )

Compute generalized eigenvalues and eigenvectors of a real generalized symmetric eigenproblem of the form itype = 1: $$Ax=\lambda B x$$ itype = 2: $$ABx=\lambda x$$ itype = 3: $$BAx=\lambda x$$, where A is this matrix. A and B are assumed to be symmetric, and B has to be positive definite. Only eigenvalues in the interval (lower_bound, upper_bound] are computed with the absolute tolerance abs_accuracy. An approximate eigenvalue is accepted as converged when it is determined to lie in an interval [a,b] of width less than or equal to abs_accuracy + eps * max( |a|,|b| ), where eps is the machine precision. If abs_accuracy is less than or equal to zero, then eps*|t| will be used in its place, where |t| is the 1-norm of the tridiagonal matrix obtained by reducing A to tridiagonal form. Eigenvalues will be computed most accurately when abs_accuracy is set to twice the underflow threshold, not zero. After this routine has been called, all eigenvalues in (lower_bound, upper_bound] will be stored in eigenvalues and the corresponding eigenvectors will be stored in eigenvectors, whose dimension is set accordingly.

Note
Calls the LAPACK function Xsygvx. For this to work, deal.II must be configured to use LAPACK.

Definition at line 1187 of file lapack_full_matrix.cc.

template<typename number>
 void LAPACKFullMatrix< number >::compute_generalized_eigenvalues_symmetric ( LAPACKFullMatrix< number > & B, std::vector< Vector< number > > & eigenvectors, const int itype = 1 )

Same as the other compute_generalized_eigenvalues_symmetric function except that all eigenvalues are computed and the tolerance is set automatically. Note that this function does not return the computed eigenvalues right away since that involves copying data around between the output arrays of the LAPACK functions and any return array. This is often unnecessary since one may not be interested in all eigenvalues at once, but for example only the extreme ones. In that case, it is cheaper to just have this function compute the eigenvalues and have a separate function that returns whatever eigenvalue is requested. Eigenvalues can be retrieved using the eigenvalue() function. The number of computed eigenvectors is equal to eigenvectors.size()

Note
Calls the LAPACK function Xsygv. For this to work, deal.II must be configured to use LAPACK.

Definition at line 1279 of file lapack_full_matrix.cc.

template<typename number >
 void LAPACKFullMatrix< number >::compute_svd ( )

Compute the singular value decomposition of the matrix using LAPACK function Xgesdd.

Requires that the state is LAPACKSupport::matrix, fills the data members wr, svd_u, and svd_vt, and leaves the object in the state LAPACKSupport::svd.

Definition at line 785 of file lapack_full_matrix.cc.

template<typename number >
 void LAPACKFullMatrix< number >::compute_inverse_svd ( const double threshold = 0. )

Compute the inverse of the matrix by singular value decomposition.

Requires that state is either LAPACKSupport::matrix or LAPACKSupport::svd. In the first case, this function calls compute_svd(). After this function, the object will have the state LAPACKSupport::inverse_svd.

For a singular value decomposition, the inverse is simply computed by replacing all singular values by their reciprocal values. If the matrix does not have maximal rank, singular values 0 are not touched, thus computing the minimal norm right inverse of the matrix.

The parameter threshold determines, when a singular value should be considered zero. It is the ratio of the smallest to the largest nonzero singular value smax. Thus, the inverses of all singular values less than smax/threshold will be set to zero.

Definition at line 830 of file lapack_full_matrix.cc.

template<typename number >
 std::complex< number > LAPACKFullMatrix< number >::eigenvalue ( const size_type i ) const
inline

Retrieve eigenvalue after compute_eigenvalues() was called.

Definition at line 942 of file lapack_full_matrix.h.

template<typename number >
 number LAPACKFullMatrix< number >::singular_value ( const size_type i ) const
inline

Retrieve singular values after compute_svd() or compute_inverse_svd() was called.

Definition at line 955 of file lapack_full_matrix.h.

template<typename number >
 void LAPACKFullMatrix< number >::print_formatted ( std::ostream & out, const unsigned int precision = 3, const bool scientific = true, const unsigned int width = 0, const char * zero_string = " ", const double denominator = 1., const double threshold = 0. ) const

Print the matrix and allow formatting of entries.

The parameters allow for a flexible setting of the output format:

• precision denotes the number of trailing digits.
• scientific is used to determine the number format, where scientific = false means fixed point notation.
• width denotes the with of each column. A zero entry for width makes the function compute a width, but it may be changed to a positive value, if output is crude.
• zero_string specifies a string printed for zero entries.
• denominator Multiply the whole matrix by this common denominator to get nicer numbers.
• threshold: all entries with absolute value smaller than this are considered zero.
Note
The entries stored resemble a matrix only if the state is either LAPACKSupport::matrix or LAPACK::inverse_matrix. Otherwise, calling this function is not allowed.

Definition at line 1354 of file lapack_full_matrix.cc.

template<typename number >
 number LAPACKFullMatrix< number >::norm ( const char type ) const
private

Internal function to compute various norms.

Definition at line 646 of file lapack_full_matrix.cc.

## Member Data Documentation

template<typename number>
 LAPACKSupport::State LAPACKFullMatrix< number >::state
private

Since LAPACK operations notoriously change the meaning of the matrix entries, we record the current state after the last operation here.

Definition at line 718 of file lapack_full_matrix.h.

template<typename number>
 LAPACKSupport::Property LAPACKFullMatrix< number >::property
private

Additional property of the matrix which may help to select more efficient LAPACK functions.

Definition at line 724 of file lapack_full_matrix.h.

template<typename number>
 std::vector LAPACKFullMatrix< number >::work
mutableprivate

The working array used for some LAPACK functions.

Definition at line 729 of file lapack_full_matrix.h.

template<typename number>
 std::vector LAPACKFullMatrix< number >::iwork
mutableprivate

Integer working array used for some LAPACK functions.

Definition at line 734 of file lapack_full_matrix.h.

template<typename number>
 std::vector LAPACKFullMatrix< number >::ipiv
private

The vector storing the permutations applied for pivoting in the LU- factorization.

Also used as the scratch array IWORK for LAPACK functions needing it.

Definition at line 742 of file lapack_full_matrix.h.

template<typename number>
 std::vector LAPACKFullMatrix< number >::inv_work
private

Workspace for calculating the inverse matrix from an LU factorization.

Definition at line 747 of file lapack_full_matrix.h.

template<typename number>
 std::vector LAPACKFullMatrix< number >::wr
private

Real parts of eigenvalues or the singular values. Filled by compute_eigenvalues() or compute_svd().

Definition at line 753 of file lapack_full_matrix.h.

template<typename number>
 std::vector LAPACKFullMatrix< number >::wi
private

Imaginary parts of eigenvalues. Filled by compute_eigenvalues.

Definition at line 758 of file lapack_full_matrix.h.

template<typename number>
 std::vector LAPACKFullMatrix< number >::vl
private

Space where left eigenvectors can be stored.

Definition at line 763 of file lapack_full_matrix.h.

template<typename number>
 std::vector LAPACKFullMatrix< number >::vr
private

Space where right eigenvectors can be stored.

Definition at line 768 of file lapack_full_matrix.h.

template<typename number>
 std::shared_ptr > LAPACKFullMatrix< number >::svd_u
private

The matrix U in the singular value decomposition USVT.

Definition at line 774 of file lapack_full_matrix.h.

template<typename number>
 std::shared_ptr > LAPACKFullMatrix< number >::svd_vt
private

The matrix VT in the singular value decomposition USVT.

Definition at line 780 of file lapack_full_matrix.h.

template<typename number>