CRS_Matrix Class Reference

#include <getmatrix.h>

Public Member Functions
	CRS_Matrix (Mesh const &mesh)
	~CRS_Matrix ()
void	Derive_Matrix_Pattern ()
void	CalculateLaplace (std::vector< double > &f)
void	ApplyDirichletBC (std::vector< double > const &u, std::vector< double > &f)
void	GetDiag (std::vector< double > &d) const
void	Mult (std::vector< double > &w, std::vector< double > const &u) const
void	Defect (std::vector< double > &w, std::vector< double > const &f, std::vector< double > const &u) const
int	Nrows () const
void	Debug () const
int	fetch (int row, int col) const
void	AddElem_3 (int const ial[3], double const ske[3][3], double const fe[3], std::vector< double > &f)
bool	Compare2Old (int nnode, int const id[], int const ik[], double const sk[]) const

Detailed Description

Square matrix in CRS format (compressed row storage; also named CSR), see an introduction.

Definition at line 42 of file getmatrix.h.

Constructor & Destructor Documentation

CRS_Matrix()

CRS_Matrix::CRS_Matrix ( Mesh const &  mesh )

explicit

Intializes the CRS matrix structure from the given discetization in mesh.

The sparse matrix pattern is generated but the values are 0.

Parameters

[in]

mesh

given discretization

Warning

A reference to the discretization mesh is stored inside this class. Therefore, changing mesh outside requires also to call method Derive_Matrix_Pattern explicitely.

See also

Derive_Matrix_Pattern

Definition at line 88 of file getmatrix.cpp.

~CRS_Matrix()

CRS_Matrix::~CRS_Matrix ( )

inline

Destructor.

Definition at line 63 of file getmatrix.h.

Member Function Documentation

AddElem_3()

void CRS_Matrix::AddElem_3	(	int const	ial[3],
		double const	ske[3][3],
		double const	fe[3],
		std::vector< double > &	f
	)

Adds the element stiffness matrix ske and the element load vector fe of one triangular element with linear shape functions to the appropriate positions in the stiffness matrix, stored as CSR matrix K(sk,id, ik).

Parameters

[in]	ial	node indices of the three element vertices
[in]	ske	element stiffness matrix
[in]	fe	element load vector
[in,out]	f	distributed local vector storing the right hand side

Warning

Algorithm assumes linear triangular elements (ndof_e==3).

Definition at line 326 of file getmatrix.cpp.

ApplyDirichletBC()

void CRS_Matrix::ApplyDirichletBC	(	std::vector< double > const &	u,
		std::vector< double > &	f
	)

Applies Dirichlet boundary conditions to stiffness matrix and to load vector f. The penalty method is used for incorporating the given values u.

Parameters

[in]	u	(global) vector with Dirichlet data
[in,out]	f	load vector

Definition at line 200 of file getmatrix.cpp.

CalculateLaplace()

void CRS_Matrix::CalculateLaplace

(

std::vector< double > &

f

)

Calculates the entries of f.e. stiffness matrix and load/rhs vector f for the Laplace operator in 2D. No memory is allocated.

Parameters

[in,out]

f

(preallocated) rhs/load vector

Definition at line 169 of file getmatrix.cpp.

Compare2Old()

bool CRS_Matrix::Compare2Old	(	int	nnode,
		int const	id[],
		int const	ik[],
		double const	sk[]
	)		const

Compare this CRS matrix with an external CRS matrix stored in C-Style.

The method prints statements on differences found.

Parameters

[in]	nnode	row number of external matrix
[in]	id	start indices of matrix rows of external matrix
[in]	ik	column indices of external matrix
[in]	sk	non-zero values of external matrix

Returns

true iff all data are identical.

Definition at line 231 of file getmatrix.cpp.

Debug()

void CRS_Matrix::Debug

(

)

const

Show the matrix entries.

Definition at line 148 of file getmatrix.cpp.

Defect()

void CRS_Matrix::Defect	(	std::vector< double > &	w,
		std::vector< double > const &	f,
		std::vector< double > const &	u
	)		const

Calculates the defect/residuum w := f - K*u.

Parameters

[in,out]	w	resulting vector (preallocated)
[in]	f	load vector
[in]	u	vector

Definition at line 284 of file getmatrix.cpp.

Derive_Matrix_Pattern()

void CRS_Matrix::Derive_Matrix_Pattern

(

)

Generates the sparse matrix pattern and overwrites the existing pattern.

The sparse matrix pattern is generated but the values are 0.

Definition at line 95 of file getmatrix.cpp.

fetch()

int CRS_Matrix::fetch	(	int	row,
		int	col
	)		const

Finds in a CRS matrix the access index for an entry at row row and column col.

Parameters

[in]	row	row index
[in]	col	column index

Returns

index for element (row, col). If no appropriate entry exists then -1 will be returned.

Warning

assert() stops the function in case that matrix element (row, col) doesn't exist.

Definition at line 302 of file getmatrix.cpp.

GetDiag()

void CRS_Matrix::GetDiag

(

std::vector< double > &

d

)

const

Extracts the diagonal elemenst of the sparse matrix.

Parameters

[in,out]

d

(prellocated) vector of diagonal elements

Definition at line 218 of file getmatrix.cpp.

Mult()

void CRS_Matrix::Mult	(	std::vector< double > &	w,
		std::vector< double > const &	u
	)		const

Performs the matrix-vector product w := K*u.

Parameters

[in,out]	w	resulting vector (preallocated)
[in]	u	vector

Definition at line 267 of file getmatrix.cpp.

Nrows()

int CRS_Matrix::Nrows ( ) const

inline

Number rows in matrix.

Returns

number of rows.

Definition at line 120 of file getmatrix.h.

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

• getmatrix.h
• getmatrix.cpp