CG or the conjugate gradient method is an iterative type Krylov subspace method which is suitable for symmetric positive definite methods.
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std::unique_ptr< LinOp > | transpose () const override |
| Returns a LinOp representing the transpose of the Transposable object.
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std::unique_ptr< LinOp > | conj_transpose () const override |
| Returns a LinOp representing the conjugate transpose of the Transposable object.
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bool | apply_uses_initial_guess () const override |
| Return true as iterative solvers use the data in x as an initial guess.
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const parameters_type & | get_parameters () const |
const Cg< default_precision > * | apply (ptr_param< const LinOp > b, ptr_param< LinOp > x) const |
std::unique_ptr< Cg< default_precision > > | create_default (std::shared_ptr< const Executor > exec) const |
std::unique_ptr< Cg< default_precision > > | clone (std::shared_ptr< const Executor > exec) const |
Cg< default_precision > * | copy_from (const PolymorphicObject *other) |
Cg< default_precision > * | move_from (ptr_param< PolymorphicObject > other) |
Cg< default_precision > * | clear () |
LinOp * | apply (ptr_param< const LinOp > b, ptr_param< LinOp > x) |
| Applies a linear operator to a vector (or a sequence of vectors).
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const LinOp * | apply (ptr_param< const LinOp > b, ptr_param< LinOp > x) const |
LinOp * | apply (ptr_param< const LinOp > alpha, ptr_param< const LinOp > b, ptr_param< const LinOp > beta, ptr_param< LinOp > x) |
| Performs the operation x = alpha * op(b) + beta * x.
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const LinOp * | apply (ptr_param< const LinOp > alpha, ptr_param< const LinOp > b, ptr_param< const LinOp > beta, ptr_param< LinOp > x) const |
const dim< 2 > & | get_size () const noexcept |
| Returns the size of the operator.
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LinOp & | operator= (const LinOp &)=default |
| Copy-assigns a LinOp.
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LinOp & | operator= (LinOp &&other) |
| Move-assigns a LinOp.
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| LinOp (const LinOp &)=default |
| Copy-constructs a LinOp.
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| LinOp (LinOp &&other) |
| Move-constructs a LinOp.
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std::unique_ptr< LinOp > | create_default (std::shared_ptr< const Executor > exec) const |
std::unique_ptr< LinOp > | clone (std::shared_ptr< const Executor > exec) const |
LinOp * | copy_from (const PolymorphicObject *other) |
LinOp * | move_from (ptr_param< PolymorphicObject > other) |
LinOp * | clear () |
PolymorphicObject & | operator= (const PolymorphicObject &) |
std::unique_ptr< PolymorphicObject > | create_default (std::shared_ptr< const Executor > exec) const |
| Creates a new "default" object of the same dynamic type as this object.
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std::unique_ptr< PolymorphicObject > | create_default () const |
| Creates a new "default" object of the same dynamic type as this object.
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std::unique_ptr< PolymorphicObject > | clone (std::shared_ptr< const Executor > exec) const |
| Creates a clone of the object.
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std::unique_ptr< PolymorphicObject > | clone () const |
| Creates a clone of the object.
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PolymorphicObject * | copy_from (const PolymorphicObject *other) |
| Copies another object into this object.
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template<typename Derived, typename Deleter> |
std::enable_if_t< std::is_base_of< PolymorphicObject, std::decay_t< Derived > >::value, PolymorphicObject > * | copy_from (std::unique_ptr< Derived, Deleter > &&other) |
| Moves another object into this object.
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template<typename Derived, typename Deleter> |
std::enable_if_t< std::is_base_of< PolymorphicObject, std::decay_t< Derived > >::value, PolymorphicObject > * | copy_from (const std::unique_ptr< Derived, Deleter > &other) |
| Copies another object into this object.
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PolymorphicObject * | copy_from (const std::shared_ptr< const PolymorphicObject > &other) |
| Copies another object into this object.
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PolymorphicObject * | move_from (ptr_param< PolymorphicObject > other) |
| Moves another object into this object.
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PolymorphicObject * | clear () |
| Transforms the object into its default state.
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std::shared_ptr< const Executor > | get_executor () const noexcept |
| Returns the Executor of the object.
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void | add_logger (std::shared_ptr< const Logger > logger) override |
| Adds a new logger to the list of subscribed loggers.
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void | remove_logger (const Logger *logger) override |
| Removes a logger from the list of subscribed loggers.
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const std::vector< std::shared_ptr< const Logger > > & | get_loggers () const override |
| Returns the vector containing all loggers registered at this object.
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void | clear_loggers () override |
| Remove all loggers registered at this object.
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void | remove_logger (ptr_param< const Logger > logger) |
void | convert_to (result_type *result) const override |
void | move_to (result_type *result) override |
EnableSolverBase & | operator= (const EnableSolverBase &other) |
| Creates a shallow copy of the provided system matrix, clones it onto this executor if executors don't match.
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int | get_num_workspace_ops () const override |
std::vector< std::string > | get_workspace_op_names () const override |
std::vector< int > | get_workspace_scalars () const override |
| Returns the IDs of all scalars (workspace vectors with system dimension-independent size, usually 1 x num_rhs).
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std::vector< int > | get_workspace_vectors () const override |
| Returns the IDs of all vectors (workspace vectors with system dimension-dependent size, usually system_matrix_size x num_rhs).
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std::shared_ptr< const LinOp > | get_system_matrix () const |
| Returns the system matrix, with its concrete type, used by the solver.
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EnableIterativeBase & | operator= (const EnableIterativeBase &other) |
| Creates a shallow copy of the provided stopping criterion, clones it onto this executor if executors don't match.
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void | set_stop_criterion_factory (std::shared_ptr< const stop::CriterionFactory > new_stop_factory) override |
| Sets the stopping criterion of the solver.
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std::shared_ptr< const stop::CriterionFactory > | get_stop_criterion_factory () const |
| Gets the stopping criterion factory of the solver.
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void | set_preconditioner (std::shared_ptr< const LinOp > new_precond) override |
| Sets the preconditioner operator used by the Preconditionable.
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EnablePreconditionable & | operator= (const EnablePreconditionable &other) |
| Creates a shallow copy of the provided preconditioner, clones it onto this executor if executors don't match.
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virtual std::shared_ptr< const LinOp > | get_preconditioner () const |
| Returns the preconditioner operator used by the Preconditionable.
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template<typename ValueType = default_precision>
class gko::solver::Cg< ValueType >
CG or the conjugate gradient method is an iterative type Krylov subspace method which is suitable for symmetric positive definite methods.
Though this method performs very well for symmetric positive definite matrices, it is in general not suitable for general matrices.
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 CG are merged into 2 separate steps.
- Template Parameters
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ValueType | precision of matrix elements |