sparseqr::QR Class Reference

QR factorization. More...

#include <sparseqr.hh>

Public Member Functions
void	BackSolve (int rank, double *x)
	Performes backsolve. More...
int	givens (int, int, int)
	Performs Given's rotations. More...
	QR (Packed *qrpmatrix, int qrnr, int qrnc, double *qrb=NULL, Qmatrix *qrq=NULL, int *qrprow=NULL, int *qrpcol=NULL, double qrztol=DBL_EPSILON, double qrrtol=0.0)
	Constructor. More...
void	RemoveEntry (int, int)
Smatrix *	RemoveEntry (int, int, Smatrix *, Smatrix *)
int	RemoveMarkedEntries (int)
int	sparseqr ()
	Performs QR factorization. More...
	~QR ()

Public Attributes
double *	b
bool	del_pcol
bool	del_prow
	Stores if delete[] of prow and pcol is allowed. More...
int	nc
int	nr
unsigned *	nrow
int *	pcol
Packed *	pmatrix
int *	prow
Qmatrix *	q
double	rtol
Smatrix **	scol
Smatrix **	srow
double	ztol

Detailed Description

QR factorization.

Author

Thomas H. Robey, 1996, 1997, 1998

See also

Homepage of SparseQR
Thomas H. Robey and Deborah L. Sulsky, Row Ordering for Sparse QR Decomposition, SIAM J. Matrix Anal. and Appl., Vol. 15, No. 4, pp. 1208-1225, October 1994.

Definition at line 128 of file sparseqr.hh.

Constructor & Destructor Documentation

QR()

sparseqr::QR::QR	(	Packed *	qrpmatrix,
		int	qrnr,
		int	qrnc,
		double *	qrb = NULL,
		Qmatrix *	qrq = NULL,
		int *	qrprow = NULL,
		int *	qrpcol = NULL,
		double	qrztol = DBL_EPSILON,
		double	qrrtol = 0.0
	)

Constructor.

Parameters

qrpmatrix	Matrix which should be factorized in sparse format
qrnr	Number of rows of the matrix
qrnc	Number of columns of the matrix
qrb	Right hand side
qrq	Space to store the Given's rotations. Does not need to be given, if they should not be stored (ie. solving for just 1 right hand side).
qrprow	Permutation vector for row indices. If not given, is allocated by the class.
qrpcol	Permutation vector for column indices. If not given, is allocated by the class.
qrztol	Tolerance for use in determining zero entries when using Given's rotations. If zero or negative, only zero entries are deleted.
rtol	Tolerance for use in determining rank tolerance by testing the diagonal entry in the final R matrix.

~QR()

sparseqr::QR::~QR

(

)

Member Function Documentation

BackSolve()

void sparseqr::QR::BackSolve	(	int	rank,
		double *	x
	)

Performes backsolve.

Parameters

rank	Rank of the matrix
x	Preallocated space to store solution

givens()

int sparseqr::QR::givens	(	int	,
		int	,
		int
	)

Performs Given's rotations.

RemoveEntry() [1/2]

void sparseqr::QR::RemoveEntry	(	int	,
		int
	)

RemoveEntry() [2/2]

Smatrix* sparseqr::QR::RemoveEntry	(	int	,
		int	,
		Smatrix *	,
		Smatrix *
	)

RemoveMarkedEntries()

int sparseqr::QR::RemoveMarkedEntries

(

int

)

sparseqr()

int sparseqr::QR::sparseqr

(

)

Performs QR factorization.

Returns

Rank of factorized matrix

Member Data Documentation

b

double * sparseqr::QR::b

Definition at line 137 of file sparseqr.hh.

del_pcol

bool sparseqr::QR::del_pcol

Definition at line 132 of file sparseqr.hh.

del_prow

bool sparseqr::QR::del_prow

Stores if delete[] of prow and pcol is allowed.

Definition at line 132 of file sparseqr.hh.

nc

int sparseqr::QR::nc

Definition at line 130 of file sparseqr.hh.

nr

int sparseqr::QR::nr

Definition at line 130 of file sparseqr.hh.

nrow

unsigned* sparseqr::QR::nrow

Definition at line 133 of file sparseqr.hh.

pcol

int * sparseqr::QR::pcol

Definition at line 130 of file sparseqr.hh.

pmatrix

Packed* sparseqr::QR::pmatrix

Definition at line 138 of file sparseqr.hh.

prow

int * sparseqr::QR::prow

Definition at line 130 of file sparseqr.hh.

q

Qmatrix* sparseqr::QR::q

Definition at line 140 of file sparseqr.hh.

rtol

double sparseqr::QR::rtol

Definition at line 137 of file sparseqr.hh.

scol

Smatrix ** sparseqr::QR::scol

Definition at line 139 of file sparseqr.hh.

srow

Smatrix** sparseqr::QR::srow

Definition at line 139 of file sparseqr.hh.

ztol

double sparseqr::QR::ztol

Definition at line 137 of file sparseqr.hh.

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

• sparseqr/sparseqr.hh