Linear solvers

Interfaces to different libraries of linear solvers. More...

Collaboration diagram for Linear solvers:

Namespaces
namespace	petibm::linsolver
	Collection of linear solvers from different libraries.

Classes
class	petibm::linsolver::LinSolverBase
	The abstract (base) class for different iterative solvers. More...
class	petibm::linsolver::LinSolverAmgX
	Iterative solver using wrapper of AmgX. More...
class	petibm::linsolver::LinSolverKSP
	Iterative solver using PETSc KSP. More...

Typedefs
typedef std::shared_ptr< linsolver::LinSolverBase >	petibm::type::LinSolver
	Type definition of LinSolver. More...

Functions
PetscErrorCode	petibm::linsolver::createLinSolver (const std::string &solverName, const YAML::Node &node, type::LinSolver &solver)
	A factory function for creating a LinSolver. More...

Detailed Description

Interfaces to different libraries of linear solvers.

The design of PetIBM is to use shared pointer (std::shared_ptr) to hold instances. The class LinSolverBase is the abstract class for all kinds of linear solver classes. With an abstract class, we can unified the interfaces of different linear solver classes. Users should use the factory function petibm::linsolver::createLinSolver to create an instance, instead of initializing the instance directly.

Currently, there are two different linear solvers: PETSc KSP and NVIDIA AmgX. Please see petibm::linsolver::createLinSolver for how to create different types of linear solver instances.

The shared pointer holding a linear solver instance is defined as petibm::type::LinSolver.

Typedef Documentation

LinSolver

typedef std::shared_ptr<linsolver::LinSolverBase> petibm::type::LinSolver

Type definition of LinSolver.

Use petibm::linsolver::createLinSolver to create a LinSolver object.

Example Usage:

 PetscErrorCode ierr;
 Mat A;
 Vec lhs, rhs;
 petibm::type::LinSolver solver;
.
 // create LinSolver with petibm::linsolver::createLinSolver
 // create matrix A, vectors lhs and rhs. See PETSc manual.
 
 ierr = solver->setMatrix(A); CKERRQ(ierr);
 ierr = solver->solve(lhs, rhs); CHKERRQ(ierr);

See also

petibm::linsolver::createLinSolver, petibm::linsolver::LinSolverBase.

Definition at line 174 of file linsolver.h.

Function Documentation

createLinSolver()

PetscErrorCode petibm::linsolver::createLinSolver	(	const std::string &	solverName,
		const YAML::Node &	node,
		type::LinSolver &	solver
	)

A factory function for creating a LinSolver.

Parameters

solverName	[in] Name of the linear solver.
node	[in] YAML configuration node.
solver	[out] The linear solver.

This function will look into the parameters and find the child key <solverName>Solver. Under <solverName>Solver, there should at least be two child keys: type and config. type indicate the type of the solver, and config provides the path to the the solver configuration file.

For example, if the name of the target LinSolver is velocity, this factory function will use node[parameters][velocitySolver][type]and node[parameters][velocitySolver][config] to determine the type and the path to the configuration file for the underlying linear solver.

Currently in PetIBM, the key type only accepts CPU and GPU.

An example of creating a LinSolver instance with KSP:

YAML::Node node;
node["parameters"]["velocitySolver"]["type"] = "CPU";
node["parameters"]["velocitySolver"]["config"] = "solversPetscOptions.info";
 
PetscErrorCode ierr;
petibm::type::LinSolver solver;
ierr = petibm::linsolver::createLinSolver(
    "velocity", node, solver); CHKERRQ(ierr);

Returns

PetscErrorCode.

See also

petibm::type::LinSolver

Definition at line 57 of file linsolver.cpp.