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Spectra 1.1.0
Header-only C++ Library for Large Scale Eigenvalue Problems
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Spectra::DenseSymShiftSolve< Scalar_, Uplo, Flags > Class Template Reference

#include <Spectra/MatOp/DenseSymShiftSolve.h>

Public Types

using Scalar = Scalar_
 

Public Member Functions

template<typename Derived>
 DenseSymShiftSolve (const Eigen::MatrixBase< Derived > &mat)
 
Index rows () const
 
Index cols () const
 
void set_shift (const Scalar &sigma)
 
void perform_op (const Scalar *x_in, Scalar *y_out) const
 

Detailed Description

template<typename Scalar_, int Uplo = Eigen::Lower, int Flags = Eigen::ColMajor>
class Spectra::DenseSymShiftSolve< Scalar_, Uplo, Flags >

This class defines the shift-solve operation on a real symmetric matrix A, i.e., calculating y=(A-\sigma I)^{-1}x for any real \sigma and vector x. It is mainly used in the SymEigsShiftSolver eigen solver.

Template Parameters
Scalar_The element type of the matrix, for example, float, double, and long double.
UploEither Eigen::Lower or Eigen::Upper, indicating which triangular part of the matrix is used.
FlagsEither Eigen::ColMajor or Eigen::RowMajor, indicating the storage format of the input matrix.

Definition at line 33 of file DenseSymShiftSolve.h.

Member Typedef Documentation

◆ Scalar

template<typename Scalar_, int Uplo = Eigen::Lower, int Flags = Eigen::ColMajor>
using Spectra::DenseSymShiftSolve< Scalar_, Uplo, Flags >::Scalar = Scalar_

Element type of the matrix.

Definition at line 39 of file DenseSymShiftSolve.h.

Constructor & Destructor Documentation

◆ DenseSymShiftSolve()

template<typename Scalar_, int Uplo = Eigen::Lower, int Flags = Eigen::ColMajor>
template<typename Derived>
Spectra::DenseSymShiftSolve< Scalar_, Uplo, Flags >::DenseSymShiftSolve ( const Eigen::MatrixBase< Derived > & mat)
inline

Constructor to create the matrix operation object.

Parameters
matAn Eigen matrix object, whose type can be Eigen::Matrix<Scalar, ...> (e.g. Eigen::MatrixXd and Eigen::MatrixXf), or its mapped version (e.g. Eigen::Map<Eigen::MatrixXd>).

Definition at line 63 of file DenseSymShiftSolve.h.

Member Function Documentation

◆ rows()

template<typename Scalar_, int Uplo = Eigen::Lower, int Flags = Eigen::ColMajor>
Index Spectra::DenseSymShiftSolve< Scalar_, Uplo, Flags >::rows ( ) const
inline

Return the number of rows of the underlying matrix.

Definition at line 77 of file DenseSymShiftSolve.h.

◆ cols()

template<typename Scalar_, int Uplo = Eigen::Lower, int Flags = Eigen::ColMajor>
Index Spectra::DenseSymShiftSolve< Scalar_, Uplo, Flags >::cols ( ) const
inline

Return the number of columns of the underlying matrix.

Definition at line 81 of file DenseSymShiftSolve.h.

◆ set_shift()

template<typename Scalar_, int Uplo = Eigen::Lower, int Flags = Eigen::ColMajor>
void Spectra::DenseSymShiftSolve< Scalar_, Uplo, Flags >::set_shift ( const Scalar & sigma)
inline

Set the real shift \sigma.

Definition at line 86 of file DenseSymShiftSolve.h.

◆ perform_op()

template<typename Scalar_, int Uplo = Eigen::Lower, int Flags = Eigen::ColMajor>
void Spectra::DenseSymShiftSolve< Scalar_, Uplo, Flags >::perform_op ( const Scalar * x_in,
Scalar * y_out ) const
inline

Perform the shift-solve operation y=(A-\sigma I)^{-1}x.

Parameters
x_inPointer to the x vector.
y_outPointer to the y vector.

Definition at line 100 of file DenseSymShiftSolve.h.


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