gko::solver::Gmres#
Generalised minimal residual. Builds an orthonormal Krylov basis and
minimises the residual over it; the most robust general-purpose
non-symmetric Krylov method. Memory grows linearly with iteration
count, so it is typically run with restart (the krylov_dim factory
parameter).
-
template<typename ValueType = default_precision>
class Gmres # Inherits from
public gko::EnableLinOp<Gmres<default_precision>>
public gko::solver::EnablePreconditionedIterativeSolver<default_precision, Gmres<default_precision>>
public gko::Transposable
GMRES or the generalized minimal residual method is an iterative type Krylov subspace method which is suitable for nonsymmetric linear systems.
The implementation in Ginkgo makes use of the merged kernel to make the best use of data locality. The inner operations in one iteration of GMRES are merged into 2 separate steps. Modified Gram-Schmidt is used.
- Template Parameters:
ValueType – precision of matrix elements
Public Functions
-
virtual std::unique_ptr<LinOp> transpose() const override#
Returns a LinOp representing the transpose of the Transposable object.
- Returns:
a pointer to the new transposed object
-
virtual std::unique_ptr<LinOp> conj_transpose() const override#
Returns a LinOp representing the conjugate transpose of the Transposable object.
- Returns:
a pointer to the new conjugate transposed object
-
inline bool apply_uses_initial_guess() const override#
Return true as iterative solvers use the data in x as an initial guess.
- Returns:
true as iterative solvers use the data in x as an initial guess.
-
inline size_type get_krylov_dim() const#
Gets the Krylov dimension of the solver
- Returns:
the Krylov dimension
-
inline void set_krylov_dim(size_type other)#
Sets the Krylov dimension
- Parameters:
other – the new Krylov dimension
Public Static Functions
- static parameters_type parse(
- const config::pnode &config,
- const config::registry &context,
- const config::type_descriptor &td_for_child = config::make_type_descriptor<ValueType>(),
Create the parameters from the property_tree. Because this is directly tied to the specific type, the value/index type settings within config are ignored and type_descriptor is only used for children configs.
- Parameters:
config – the property tree for setting
context – the registry
td_for_child – the type descriptor for children configs. The default uses the value type of this class.
- Returns:
parameters
-
struct parameters_type #
Inherits from
public gko::solver::enable_preconditioned_iterative_solver_factory_parameters<parameters_type, Factory>