gko::experimental::solver::
Direct#

Direct solver built from a sparse \(LU\) (or \(LDL^T\)) factorisation supplied by a Factorization factory. The factorisation is computed once during generate() and reused across every apply(); each apply runs a forward solve on the \(L\) factor followed by a backward solve on the \(U\) factor.

The factorisation factory is provided as the factorization factory parameter — typically a built-in factorisation (Cholesky, Lu) or a user-supplied one. The native Ginkgo triangular solvers (LowerTrs, UpperTrs) handle the substitutions.

For an introduction to direct solvers in Ginkgo, see the direct solver concept page.

template<typename ValueType, typename IndexType>
class Direct #

Inherits from

A direct solver based on a factorization into lower and upper triangular factors (with an optional diagonal scaling). The solver is built from the Factorization returned by the provided LinOpFactory.

Template Parameters:

  • ValueType – the type used to store values of the system matrix

  • IndexType – the type used to store sparsity pattern indices of the system matrix

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

Direct(const Direct&)#

Creates a copy of the solver.

Direct(Direct&&)#

Moves from the given solver, leaving it empty.

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, IndexType>(),
)#

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/index type of this class.

Returns:

parameters

struct parameters_type #

Inherits from

Public Members

gko::size_type num_rhs#

Number of right hand sides.

Note

This value is currently only required for the CUDA executor, which will throw an exception if a different number of rhs is passed to Direct::apply.

std::shared_ptr<const LinOpFactory> factorization#

The factorization factory to use for generating the factors.