Spectra  1.0.1
Header-only C++ Library for Large Scale Eigenvalue Problems
Spectra::SparseSymShiftSolve< Scalar_, Uplo, Flags, StorageIndex > Class Template Reference

#include <Spectra/MatOp/SparseSymShiftSolve.h>

Public Types

using Scalar = Scalar_
 

Public Member Functions

template<typename Derived >
 SparseSymShiftSolve (const Eigen::SparseMatrixBase< 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, typename StorageIndex = int>
class Spectra::SparseSymShiftSolve< Scalar_, Uplo, Flags, StorageIndex >

This class defines the shift-solve operation on a sparse 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.
StorageIndexThe type of the indices for the sparse matrix.

Definition at line 33 of file SparseSymShiftSolve.h.

Member Typedef Documentation

◆ Scalar

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

Element type of the matrix.

Definition at line 39 of file SparseSymShiftSolve.h.

Constructor & Destructor Documentation

◆ SparseSymShiftSolve()

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

Constructor to create the matrix operation object.

Parameters
matAn Eigen sparse matrix object, whose type can be Eigen::SparseMatrix<Scalar, ...> or its mapped version Eigen::Map<Eigen::SparseMatrix<Scalar, ...> >.

Definition at line 62 of file SparseSymShiftSolve.h.

Member Function Documentation

◆ rows()

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

Return the number of rows of the underlying matrix.

Definition at line 76 of file SparseSymShiftSolve.h.

◆ cols()

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

Return the number of columns of the underlying matrix.

Definition at line 80 of file SparseSymShiftSolve.h.

◆ set_shift()

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

Set the real shift \(\sigma\).

Definition at line 85 of file SparseSymShiftSolve.h.

◆ perform_op()

template<typename Scalar_ , int Uplo = Eigen::Lower, int Flags = Eigen::ColMajor, typename StorageIndex = int>
void Spectra::SparseSymShiftSolve< Scalar_, Uplo, Flags, StorageIndex >::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 104 of file SparseSymShiftSolve.h.


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