G+Smo  25.01.0
Geometry + Simulation Modules
 
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gsIncompleteLUOp< MatrixType > Class Template Referenceabstract

Detailed Description

template<typename MatrixType>
class gismo::gsIncompleteLUOp< MatrixType >

Incomplete LU with thresholding preconditioner.

+ Inheritance diagram for gsIncompleteLUOp< MatrixType >:
+ Collaboration diagram for gsIncompleteLUOp< MatrixType >:

Public Types

typedef gsPreconditionerOp< TBase
 Base class.
 
typedef gsLinearOperator< MatrixType::Scalar >::Ptr BasePtr
 Base class.
 
typedef memory::shared_ptr< gsIncompleteLUOpPtr
 Shared pointer for gsIncompleteLUOp.
 
typedef MatrixType::Scalar T
 Scalar type.
 
typedef memory::unique_ptr< gsIncompleteLUOpuPtr
 Unique pointer for gsIncompleteLUOp.
 

Public Member Functions

virtual void apply (const gsMatrix< T > &input, gsMatrix< T > &x) const =0
 apply the operator on the input vector and store the result in x
 
index_t cols () const
 Returns the number of columns of the operator.
 
MatrixType::Scalar estimateLargestEigenvalueOfPreconditionedSystem (index_t steps=10) const
 Estimates the largest eigenvalue of \( PA \).
 
 gsIncompleteLUOp (const MatrixPtr &mat, index_t fillfactor=1)
 Constructor with shared pointer to matrix.
 
 gsIncompleteLUOp (const MatrixType &mat, index_t fillfactor=1)
 Constructor with given matrix.
 
NestedMatrix matrix () const
 Returns the matrix.
 
MatrixPtr matrixPtr () const
 Returns a shared pinter to the matrix.
 
index_t numOfSweeps ()
 Get the number of sweeps to be applied in the member function apply.
 
index_t rows () const
 Returns the number of rows of the operator.
 
void setNumOfSweeps (index_t n)
 Set the number of sweeps to be applied in the member function apply.
 
virtual void setOptions (const gsOptionList &opt)
 Set options based on a gsOptionList object.
 
void step (const gsMatrix< T > &rhs, gsMatrix< T > &x) const
 Apply the method for given right hand side and current iterate.
 
virtual void stepT (const gsMatrix< MatrixType::Scalar > &rhs, gsMatrix< MatrixType::Scalar > &x) const
 Apply the transposed variant of the method for given right hand side and current iterate.
 
gsLinearOperator< T >::Ptr underlyingOp () const
 Return the underlying operator \( A \).
 

Static Public Member Functions

static gsOptionList defaultOptions ()
 Get the default options as gsOptionList object.
 
static gsIdentityOp< TIdentity (const index_t dim)
 Identity operator.
 

Private Attributes

NestedMatrix m_expr
 Nested Eigen expression.
 
gsEigen::IncompleteLUT< Tm_ilu
 The decomposition itself.
 
const MatrixPtr m_mat
 Shared pointer to matrix (if needed)
 

Related Symbols

(Note that these are not member symbols.)

template<class Derived >
gsIncompleteLUOp< Derived >::uPtr makeIncompleteLUOp (const gsEigen::EigenBase< Derived > &mat)
 Returns a smart pointer to a Gauss-Seidel operator referring on mat.
 
template<class Derived >
gsIncompleteLUOp< Derived >::uPtr makeIncompleteLUOp (const memory::shared_ptr< Derived > &mat)
 Returns a smart pointer to a Jacobi operator referring on mat.
 

Member Function Documentation

◆ apply()

◆ estimateLargestEigenvalueOfPreconditionedSystem()

MatrixType::Scalar estimateLargestEigenvalueOfPreconditionedSystem ( index_t  steps = 10) const
inlineinherited

Estimates the largest eigenvalue of \( PA \).

Parameters
stepsNumber of steps to be performed.

◆ step()

template<typename MatrixType >
void step ( const gsMatrix< T > &  rhs,
gsMatrix< T > &  x 
) const
inlinevirtual

Apply the method for given right hand side and current iterate.

Parameters
rhsRight hand side vector
xCurrent iterate vector

Implements gsPreconditionerOp< MatrixType::Scalar >.

◆ stepT()

virtual void stepT ( const gsMatrix< MatrixType::Scalar > &  rhs,
gsMatrix< MatrixType::Scalar > &  x 
) const
inlinevirtualinherited

Apply the transposed variant of the method for given right hand side and current iterate.

Parameters
rhsRight hand side vector
xCurrent iterate vector
Warning
Derived classes must overwrite this virtual function if the preconditioner is not symmetric.

Reimplemented in gsGaussSeidelOp< MatrixType, ordering >.