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Eigen::BiCGSTAB< _MatrixType, _Preconditioner > Class Template Reference

A bi conjugate gradient stabilized solver for sparse square problems. More...

#include <BiCGSTAB.h>

+ Inheritance diagram for Eigen::BiCGSTAB< _MatrixType, _Preconditioner >:
+ Collaboration diagram for Eigen::BiCGSTAB< _MatrixType, _Preconditioner >:

Public Types

typedef _MatrixType MatrixType
 
typedef MatrixType::Scalar Scalar
 
typedef MatrixType::Index Index
 
typedef MatrixType::RealScalar RealScalar
 
typedef _Preconditioner Preconditioner
 
- Public Types inherited from Eigen::IterativeSolverBase< BiCGSTAB< _MatrixType, _Preconditioner > >
typedef internal::traits< BiCGSTAB< _MatrixType, _Preconditioner > >::MatrixType MatrixType
 
typedef internal::traits< BiCGSTAB< _MatrixType, _Preconditioner > >::Preconditioner Preconditioner
 
typedef MatrixType::Scalar Scalar
 
typedef MatrixType::Index Index
 
typedef MatrixType::RealScalar RealScalar
 

Public Member Functions

 BiCGSTAB ()
 
 BiCGSTAB (const MatrixType &A)
 
template<typename Rhs , typename Guess >
const internal::solve_retval_with_guess< BiCGSTAB, Rhs, Guess > solveWithGuess (const MatrixBase< Rhs > &b, const Guess &x0) const
 
template<typename Rhs , typename Dest >
void _solveWithGuess (const Rhs &b, Dest &x) const
 
template<typename Rhs , typename Dest >
void _solve (const Rhs &b, Dest &x) const
 
- Public Member Functions inherited from Eigen::IterativeSolverBase< BiCGSTAB< _MatrixType, _Preconditioner > >
BiCGSTAB< _MatrixType, _Preconditioner > & derived ()
 
const BiCGSTAB< _MatrixType, _Preconditioner > & derived () const
 
 IterativeSolverBase ()
 
 IterativeSolverBase (const MatrixType &A)
 
BiCGSTAB< _MatrixType, _Preconditioner > & analyzePattern (const MatrixType &A)
 
BiCGSTAB< _MatrixType, _Preconditioner > & factorize (const MatrixType &A)
 
BiCGSTAB< _MatrixType, _Preconditioner > & compute (const MatrixType &A)
 
Index rows () const
 
Index cols () const
 
RealScalar tolerance () const
 
BiCGSTAB< _MatrixType, _Preconditioner > & setTolerance (const RealScalar &tolerance)
 
Preconditioner & preconditioner ()
 
const Preconditioner & preconditioner () const
 
int maxIterations () const
 
BiCGSTAB< _MatrixType, _Preconditioner > & setMaxIterations (int maxIters)
 
int iterations () const
 
RealScalar error () const
 
const internal::solve_retval< BiCGSTAB< _MatrixType, _Preconditioner >, Rhs > solve (const MatrixBase< Rhs > &b) const
 
const internal::sparse_solve_retval< IterativeSolverBase, Rhs > solve (const SparseMatrixBase< Rhs > &b) const
 
ComputationInfo info () const
 
void _solve_sparse (const Rhs &b, SparseMatrix< DestScalar, DestOptions, DestIndex > &dest) const
 

Additional Inherited Members

- Protected Member Functions inherited from Eigen::IterativeSolverBase< BiCGSTAB< _MatrixType, _Preconditioner > >
void init ()
 
- Protected Attributes inherited from Eigen::IterativeSolverBase< BiCGSTAB< _MatrixType, _Preconditioner > >
const MatrixType * mp_matrix
 
Preconditioner m_preconditioner
 
int m_maxIterations
 
RealScalar m_tolerance
 
RealScalar m_error
 
int m_iterations
 
ComputationInfo m_info
 
bool m_isInitialized
 
bool m_analysisIsOk
 
bool m_factorizationIsOk
 

Detailed Description

template<typename _MatrixType, typename _Preconditioner>
class Eigen::BiCGSTAB< _MatrixType, _Preconditioner >

A bi conjugate gradient stabilized solver for sparse square problems.

This class allows to solve for A.x = b sparse linear problems using a bi conjugate gradient stabilized algorithm. The vectors x and b can be either dense or sparse.

Template Parameters
_MatrixTypethe type of the sparse matrix A, can be a dense or a sparse matrix.
_Preconditionerthe type of the preconditioner. Default is DiagonalPreconditioner

The maximal number of iterations and tolerance value can be controlled via the setMaxIterations() and setTolerance() methods. The defaults are the size of the problem for the maximal number of iterations and NumTraits<Scalar>::epsilon() for the tolerance.

This class can be used as the direct solver classes. Here is a typical usage example:

int n = 10000;
VectorXd x(n), b(n);
SparseMatrix<double> A(n,n);
// fill A and b
BiCGSTAB<SparseMatrix<double> > solver;
solver(A);
x = solver.solve(b);
std::cout << "#iterations: " << solver.iterations() << std::endl;
std::cout << "estimated error: " << solver.error() << std::endl;
// update b, and solve again
x = solver.solve(b);

By default the iterations start with x=0 as an initial guess of the solution. One can control the start using the solveWithGuess() method. Here is a step by step execution example starting with a random guess and printing the evolution of the estimated error:

See also
class SimplicialCholesky, DiagonalPreconditioner, IdentityPreconditioner

Definition at line 112 of file BiCGSTAB.h.

Constructor & Destructor Documentation

template<typename _MatrixType, typename _Preconditioner>
Eigen::BiCGSTAB< _MatrixType, _Preconditioner >::BiCGSTAB ( )
inline

Default constructor.

Definition at line 190 of file BiCGSTAB.h.

190 : Base() {}
template<typename _MatrixType, typename _Preconditioner>
Eigen::BiCGSTAB< _MatrixType, _Preconditioner >::BiCGSTAB ( const MatrixType &  A)
inline

Initialize the solver with matrix A for further Ax=b solving.

This constructor is a shortcut for the default constructor followed by a call to compute().

Warning
this class stores a reference to the matrix A as well as some precomputed values that depend on it. Therefore, if A is changed this class becomes invalid. Call compute() to update it with the new matrix A, or modify a copy of A.

Definition at line 202 of file BiCGSTAB.h.

202 : Base(A) {}

Member Function Documentation

template<typename _MatrixType, typename _Preconditioner>
template<typename Rhs , typename Guess >
const internal::solve_retval_with_guess<BiCGSTAB, Rhs, Guess> Eigen::BiCGSTAB< _MatrixType, _Preconditioner >::solveWithGuess ( const MatrixBase< Rhs > &  b,
const Guess &  x0 
) const
inline
Returns
the solution x of $ A x = b $ using the current decomposition of A x0 as an initial solution.
See also
compute()

Definition at line 213 of file BiCGSTAB.h.

214  {
215  eigen_assert(m_isInitialized && "BiCGSTAB is not initialized.");
216  eigen_assert(Base::rows()==b.rows()
217  && "BiCGSTAB::solve(): invalid number of rows of the right hand side matrix b");
218  return internal::solve_retval_with_guess
219  <BiCGSTAB, Rhs, Guess>(*this, b.derived(), x0);
220  }

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