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Eigen  3.3.9
Eigen::SPQR< _MatrixType > Class Template Reference

Detailed Description

template<typename _MatrixType>
class Eigen::SPQR< _MatrixType >

Sparse QR factorization based on SuiteSparseQR library.

This class is used to perform a multithreaded and multifrontal rank-revealing QR decomposition of sparse matrices. The result is then used to solve linear leasts_square systems. Clearly, a QR factorization is returned such that A*P = Q*R where :

P is the column permutation. Use colsPermutation() to get it.

Q is the orthogonal matrix represented as Householder reflectors. Use matrixQ() to get an expression and matrixQ().transpose() to get the transpose. You can then apply it to a vector.

R is the sparse triangular factor. Use matrixQR() to get it as SparseMatrix. NOTE : The Index type of R is always SuiteSparse_long. You can get it with SPQR::Index

Template Parameters
_MatrixTypeThe type of the sparse matrix A, must be a column-major SparseMatrix<>

This class follows the sparse solver concept .

Public Member Functions

cholmod_common * cholmodCommon () const
Index cols () const
PermutationType colsPermutation () const
 Get the permutation that was applied to columns of A.
ComputationInfo info () const
 Reports whether previous computation was successful. More...
SPQRMatrixQReturnType< SPQRmatrixQ () const
 Get an expression of the matrix Q.
const MatrixType matrixR () const
Index rank () const
Index rows () const
void setPivotThreshold (const RealScalar &tol)
 Set the tolerance tol to treat columns with 2-norm < =tol as zero.
void setSPQROrdering (int ord)
 Set the fill-reducing ordering method to be used.

Member Function Documentation

◆ cholmodCommon()

template<typename _MatrixType >
cholmod_common* Eigen::SPQR< _MatrixType >::cholmodCommon ( ) const
a pointer to the SPQR workspace

◆ cols()

template<typename _MatrixType >
Index Eigen::SPQR< _MatrixType >::cols ( void  ) const

Get the number of columns of the input matrix.

◆ info()

template<typename _MatrixType >
ComputationInfo Eigen::SPQR< _MatrixType >::info ( ) const

Reports whether previous computation was successful.

Success if computation was succesful, NumericalIssue if the sparse QR can not be computed

◆ matrixR()

template<typename _MatrixType >
const MatrixType Eigen::SPQR< _MatrixType >::matrixR ( ) const
the sparse triangular factor R. It is a sparse matrix

◆ rank()

template<typename _MatrixType >
Index Eigen::SPQR< _MatrixType >::rank ( ) const

Gets the rank of the matrix. It should be equal to matrixQR().cols if the matrix is full-rank

◆ rows()

template<typename _MatrixType >
Index Eigen::SPQR< _MatrixType >::rows ( void  ) const

Get the number of rows of the input matrix and the Q matrix

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