HLIBpro  2.8.1
TLinearOperator Class Referenceabstract

Base class for all linear operators mapping vectors to vectors. More...

#include <TLinearOperator.hh>

Inheritance diagram for TLinearOperator:
TTypeInfo TFacInvMatrix TGaussSeidel TJacobi TMatrix TMatrixProduct< T_value > TMatrixSum< T_value > TNearfieldMulVec TPermMatrix TSOR

Public Member Functions

virtual bool is_complex () const =0
 return true, if field type is complex
 
virtual bool is_self_adjoint () const =0
 return true, of operator is self adjoint
 
virtual void apply (const TVector *x, TVector *y, const matop_t op=apply_normal) const =0
 
virtual void apply_add (const real alpha, const TVector *x, TVector *y, const matop_t op=apply_normal) const =0
 
virtual void apply_add (const real alpha, const BLAS::Vector< real > &x, BLAS::Vector< real > &y, const matop_t op=apply_normal) const =0
 
virtual size_t domain_dim () const =0
 return dimension of domain
 
virtual size_t range_dim () const =0
 return dimension of range
 
virtual auto domain_vector () const -> std::unique_ptr< TVector >=0
 return vector in domain space
 
virtual auto range_vector () const -> std::unique_ptr< TVector >=0
 return vector in range space
 
- Public Member Functions inherited from TTypeInfo
virtual typeid_t type () const =0
 return type ID of object
 
virtual bool is_type (const typeid_t t) const
 return true if local object is of given type ID t
 
virtual std::string typestr () const
 return string representation of type
 

Detailed Description

     Many standard arithmetic operations only depend upon a linear operator
     providing the mapping between vectors, e.g. iterativ solvers. Instead of
     requiring a full matrix and hence the need for an implementation of the
     full matrix algebra, an object of type TLinearOperator is fully sufficient
     in such cases.

Member Function Documentation

◆ apply()

virtual void apply ( const TVector x,
TVector y,
const matop_t  op = apply_normal 
) const
pure virtual

mapping function of linear operator \(A\), e.g. \( y := A(x)\). Depending on op, either \(A\), \(A^T\) or \(A^H\) is applied.

Implemented in TGaussSeidel, TSOR, TPermMatrix, TNearfieldMulVec, TMatrixSum< T_value >, TMatrixProduct< T_value >, TMatrix, TJacobi, and TFacInvMatrix.

◆ apply_add() [1/2]

virtual void apply_add ( const real  alpha,
const BLAS::Vector< real > &  x,
BLAS::Vector< real > &  y,
const matop_t  op = apply_normal 
) const
pure virtual

same as above but only the dimension of the vector spaces is tested, not the corresponding index sets

Implemented in TGaussSeidel, TSOR, TRkMatrix, TPermMatrix, TNearfieldMulVec, TMatrixSum< T_value >, TMatrixProduct< T_value >, TMatrix, TJacobi, TFacInvMatrix, TDenseMatrix, and TBlockMatrix.

◆ apply_add() [2/2]

virtual void apply_add ( const real  alpha,
const TVector x,
TVector y,
const matop_t  op = apply_normal 
) const
pure virtual

mapping function with update: \( y := y + \alpha A(x)\). Depending on op, either \(A\), \(A^T\) or \(A^H\) is applied.

Implemented in TGaussSeidel, TSOR, TPermMatrix, TNearfieldMulVec, TMatrixSum< T_value >, TMatrixProduct< T_value >, TMatrix, TJacobi, and TFacInvMatrix.