gsIterativeSolver< T > Class Template Reference

Detailed Description

template<class T = real_t>
class gismo::gsIterativeSolver< T >

Abstract class for iterative solvers.

Inheritance diagram for gsIterativeSolver< T >:

Public Member Functions
virtual std::string	detail () const
	Prints the object as a string with extended details.
T	error () const
	The relative residual error of the current iterate. More...
virtual void	finalizeIteration (VectorType &)
	Some post-processing might be required.
	gsIterativeSolver (const LinOpPtr &mat, const LinOpPtr &precond)
	Contructor using a linear operator to be solved for and a preconditioner. More...
template<typename Derived >
	gsIterativeSolver (const gsEigen::EigenBase< Derived > &mat, const LinOpPtr &precond)
	Contructor using any dense or sparse matrix and a preconditioner. More...
virtual bool	initIteration (const VectorType &rhs, VectorType &x)
	Init the iteration.
index_t	iterations () const
	The number of iterations needed to reach the error criteria.
LinOpPtr	preconditioner () const
	Get the preconditioner.
virtual std::ostream &	print (std::ostream &os) const =0
	Prints the object as a string.
void	setMaxIterations (index_t max_iters)
	Set the maximum number of iterations (default: 1000)
virtual gsIterativeSolver &	setOptions (const gsOptionList &opt)
	Set the options based on a gsOptionList.
void	setPreconditioner (const LinOpPtr &precond)
	Set the preconditionner.
void	setTolerance (T tol)
	Set the tolerance for the error criteria on the relative residual error (default: 1e-10)
index_t	size () const
	Returns the size of the linear system.
void	solve (const VectorType &rhs, VectorType &x)
	Solves the linear system and stores the solution in x. More...
void	solveDetailed (const VectorType &rhs, VectorType &x, VectorType &error_history)
	Solves the linear system and stores the solution in x and records the error histroy. More...
virtual bool	step (VectorType &x)=0
	Perform one step, requires initIteration.
T	tolerance () const
	The chosen tolerance for the error criteria on the relative residual error.
LinOpPtr	underlying () const
	Get the underlying matrix/operator to be solved for.

Static Public Member Functions
static gsOptionList	defaultOptions ()
	Returns a list of default options.

Protected Attributes
T	m_error
	The relative error as absolute_error/m_rhs_norm.
const LinOpPtr	m_mat
	The matrix/operator to be solved for.
index_t	m_max_iters
	The upper bound for the number of iterations.
index_t	m_num_iter
	The number of iterations performed.
LinOpPtr	m_precond
	The preconditioner.
T	m_rhs_norm
	The norm of the right-hand-side.
gsOptionList::Real	m_tol
	The tolerance for m_error to be reached.

Related Functions
(Note that these are not member functions.)
template<class T >
std::ostream &	operator<< (std::ostream &os, const gsIterativeSolver< T > &b)
	Print (as string) operator for iterative solvers. More...

Constructor & Destructor Documentation

gsIterativeSolver ( const LinOpPtr &  mat, const LinOpPtr &  precond  )

inline

Contructor using a linear operator to be solved for and a preconditioner.

Parameters

mat	The operator to be solved for as shared pointer to a gsLinearOperator
precond	The preconditioneras shared pointer to a gsLinearOperator, a null pointer is defaulted to the identity

gsIterativeSolver ( const gsEigen::EigenBase< Derived > &  mat, const LinOpPtr &  precond  )

inline

Contructor using any dense or sparse matrix and a preconditioner.

Parameters

mat	The operator to be solved for as a (reference) to a matrix.
precond	The preconditioneras shared pointer to a gsLinearOperator, a null pointer is defaulted to the identity

Note

This does not copy the matrix in mat. So, make sure that the matrix is not deleted before the solver. If you have a shared pointer to the matrix, you might use makeMatrixOp() to obtain a shared pointer to a gsLinearOperator which can be supplied alternatively.

Member Function Documentation

T error ( ) const

inline

The relative residual error of the current iterate.

This is the Euclidean norm of the residual, devided by the Euclidean norm of the right-hand side.

void solve ( const VectorType &  rhs, VectorType &  x  )

inline

Solves the linear system and stores the solution in x.

Solves the linear system of equations

Parameters

[in]	rhs	the right hand side of the linear system
[in,out]	x	starting value; the solution is stored in here

void solveDetailed ( const VectorType &  rhs, VectorType &  x, VectorType &  error_history  )

inline

Solves the linear system and stores the solution in x and records the error histroy.

Solves the linear system of equations

Parameters

[in]	rhs	the right hand side of the linear system
[in,out]	x	starting value; the solution is stored in here
[out]	error_history	the error history is stored here

Friends And Related Function Documentation

std::ostream & operator<< ( std::ostream &  os, const gsIterativeSolver< T > &  b  )

related

Print (as string) operator for iterative solvers.