Class PETScNewtonKrylovSolver provides a NewtonKrylovSolver interface for a PETSc inexact Newton-Krylov iterative nonlinear solver (SNES). More...

#include </home/runner/work/IBAMR/IBAMR/ibtk/include/ibtk/PETScNewtonKrylovSolver.h>

Inheritance diagram for IBTK::PETScNewtonKrylovSolver:

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Public Member Functions
	PETScNewtonKrylovSolver (std::string object_name, SAMRAI::tbox::Pointer< SAMRAI::tbox::Database > input_db, std::string default_options_prefix, MPI_Comm petsc_comm=PETSC_COMM_WORLD)
	Constructor for a concrete NewtonKrylovSolver that employs the PETSc SNES solver framework.

	PETScNewtonKrylovSolver (std::string object_name, SNES petsc_snes)
	Constructor for a concrete NewtonKrylovSolver that acts as a "wrapper" for a supplied PETSc SNES object. More...

	~PETScNewtonKrylovSolver ()
	Destructor.

void	setOptionsPrefix (const std::string &options_prefix)
	Set the options prefix used by this PETSc solver object.

Functions to access the underlying PETSc objects.
const SNES &	getPETScSNES () const
	Get the PETSc SNES object.

Public Member Functions inherited from IBTK::NewtonKrylovSolver
	NewtonKrylovSolver ()
	Default constructor.

virtual	~NewtonKrylovSolver ()=default
	Empty virtual destructor.

void	setHierarchyMathOps (SAMRAI::tbox::Pointer< HierarchyMathOps > hier_math_ops) override
	Set the HierarchyMathOps object used by the solver.

void	setHomogeneousBc (bool homogeneous_bc) override
	Set whether the solver should use homogeneous boundary conditions.

void	setSolutionTime (double solution_time) override
	Set the time at which the solution is to be evaluated.

void	setTimeInterval (double current_time, double new_time) override
	Set the current time interval.

virtual SAMRAI::tbox::Pointer< GeneralOperator >	getOperator () const
	Retrieve the nonlinear operator used by the solver.

virtual SAMRAI::tbox::Pointer< JacobianOperator >	getJacobian () const
	Retrieve the Jacobian operator used by the solver.

virtual SAMRAI::tbox::Pointer< KrylovLinearSolver >	getLinearSolver () const
	Retrieve the Krylov linear solver used in computing Newton step directions.

virtual void	setMaxEvaluations (int max_evaluations)
	Set the maximum number of function evaluations to use per solve.

virtual int	getMaxEvaluations () const
	Get the maximum number of function evaluations to use per solve.

virtual void	setSolutionTolerance (double solution_tol)
	Set the tolerance in terms of the norm of the change in the solution between steps.

virtual double	getSolutionTolerance () const
	Get the tolerance in terms of the norm of the change in the solution between steps.

virtual int	getNumLinearIterations () const
	Return the number of linear iterations from the most recent nonlinear solve.

Public Member Functions inherited from IBTK::GeneralSolver
	GeneralSolver ()=default
	Constructor.

virtual	~GeneralSolver ()=default
	Empty virtual destructor.

const std::string &	getName () const
	Return the object name.

virtual bool	getIsInitialized () const
	Return whether the operator is initialized.

virtual bool	getHomogeneousBc () const
	Return whether the solver is using homogeneous boundary conditions.

virtual double	getSolutionTime () const
	Get the time at which the solution is being evaluated.

virtual std::pair< double, double >	getTimeInterval () const
	Get the current time interval.

virtual double	getDt () const
	Get the current time step size.

virtual SAMRAI::tbox::Pointer< HierarchyMathOps >	getHierarchyMathOps () const
	Get the HierarchyMathOps object used by the solver.

virtual void	setMaxIterations (int max_iterations)
	Set the maximum number of nonlinear iterations to use per solve.

virtual int	getMaxIterations () const
	Get the maximum number of nonlinear iterations to use per solve.

virtual void	setAbsoluteTolerance (double abs_residual_tol)
	Set the absolute residual tolerance for convergence.

virtual double	getAbsoluteTolerance () const
	Get the absolute residual tolerance for convergence.

virtual void	setRelativeTolerance (double rel_residual_tol)
	Set the relative residual tolerance for convergence.

virtual double	getRelativeTolerance () const
	Get the relative residual tolerance for convergence.

virtual int	getNumIterations () const
	Return the iteration count from the most recent solve.

virtual double	getResidualNorm () const
	Return the residual norm from the most recent iteration.

virtual void	setLoggingEnabled (bool enable_logging=true)
	Enable or disable logging.

virtual bool	getLoggingEnabled () const
	Determine whether logging is enabled or disabled.

virtual void	printClassData (std::ostream &stream)
	Print class data to stream.

Static Public Member Functions
static SAMRAI::tbox::Pointer< NewtonKrylovSolver >	allocate_solver (const std::string &object_name, SAMRAI::tbox::Pointer< SAMRAI::tbox::Database > input_db, const std::string &default_options_prefix)
	Static function to construct a PETScNewtonKrylovSolver.

Newton-Krylov solver functionality.
void	setOperator (SAMRAI::tbox::Pointer< GeneralOperator > op) override
	Set the nonlinear operator used by the solver.

SAMRAI::tbox::Pointer< SAMRAI::solv::SAMRAIVectorReal< NDIM, double > >	getSolutionVector () const override
	Return the vector in which the approximate solution is stored.

SAMRAI::tbox::Pointer< SAMRAI::solv::SAMRAIVectorReal< NDIM, double > >	getFunctionVector () const override
	Return the vector in which the nonlinear function evaluation is stored.

void	setJacobian (SAMRAI::tbox::Pointer< JacobianOperator > J) override
	Set the Jacobian operator used by the solver. More...

bool	solveSystem (SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &x, SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &b) override
	Solve the system for . More...

void	initializeSolverState (const SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &x, const SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &b) override
	Compute hierarchy dependent data required for solving . More...

void	deallocateSolverState () override
	Remove all hierarchy dependent data allocated by initializeSolverState(). More...

Additional Inherited Members
Protected Member Functions inherited from IBTK::GeneralSolver
void	init (const std::string &object_name, bool homogeneous_bc)

virtual void	initSpecialized (const std::string &object_name, bool homogeneous_bc)

Protected Attributes inherited from IBTK::NewtonKrylovSolver
SAMRAI::tbox::Pointer< GeneralOperator >	d_F

SAMRAI::tbox::Pointer< JacobianOperator >	d_J

SAMRAI::tbox::Pointer< KrylovLinearSolver >	d_krylov_solver

SAMRAI::tbox::Pointer< SAMRAI::solv::SAMRAIVectorReal< NDIM, double > >	d_x

SAMRAI::tbox::Pointer< SAMRAI::solv::SAMRAIVectorReal< NDIM, double > >	d_b

SAMRAI::tbox::Pointer< SAMRAI::solv::SAMRAIVectorReal< NDIM, double > >	d_r

int	d_max_evaluations = 10000

double	d_solution_tol = 1.0e-8

int	d_current_linear_iterations = 0

Protected Attributes inherited from IBTK::GeneralSolver
std::string	d_object_name = "unitialized"

bool	d_is_initialized = false

bool	d_homogeneous_bc = false

double	d_solution_time = std::numeric_limits<double>::quiet_NaN()

double	d_current_time = std::numeric_limits<double>::quiet_NaN()

double	d_new_time = std::numeric_limits<double>::quiet_NaN()

double	d_rel_residual_tol = 0.0

double	d_abs_residual_tol = 0.0

int	d_max_iterations = 100

int	d_current_iterations = 0

double	d_current_residual_norm = std::numeric_limits<double>::quiet_NaN()

SAMRAI::tbox::Pointer< HierarchyMathOps >	d_hier_math_ops

bool	d_hier_math_ops_external = false

bool	d_enable_logging = false

Detailed Description

Class PETScNewtonKrylovSolver provides a NewtonKrylovSolver interface for a PETSc inexact Newton-Krylov iterative nonlinear solver (SNES).

This solver class provides access to inexact Newton-Krylov methods, including line search and trust region Newton methods, using the PETSc SNES nonlinear solver interface. Note that solver configuration is typically done at runtime via command line options.

Note

Users have the option of supplying the PETScNewtonKrylovSolver class constructor with a SNES object. It is important to emphasize that doing so is optional. When a SNES object is provided to the class constructor, the PETScNewtonKrylovSolver class acts as a wrapper for the supplied SNES object.

The functionality of the PETScNewtonKrylovSolver class is essentially identical regardless as to whether a PETSc SNES object is provided to the class constructor. The main exception is that when an external SNES object is provided to the class constructor, memory management of that object is NOT handled by the PETScNewtonKrylovSolver. In particular, it is the caller's responsibility to ensure that the supplied SNES object is properly destroyed via SNESDestroy().

Sample parameters for initialization from database (and their default values):

options_prefix = ""           // see setOptionsPrefix()
rel_residual_tol = 1.0e-8     // see setRelativeTolerance()
abs_residual_tol = 1.0e-50    // see setAbsoluteTolerance()
solution_tol = 1.0e-8         // see setSolutionTolerance()
max_iterations = 50           // see setMaxIterations()
enable_logging = FALSE        // see setLoggingEnabled()

PETSc is developed in the Mathematics and Computer Science (MCS) Division at Argonne National Laboratory (ANL). For more information about PETSc, see http://www.mcs.anl.gov/petsc.

Constructor & Destructor Documentation

◆ PETScNewtonKrylovSolver()

IBTK::PETScNewtonKrylovSolver::PETScNewtonKrylovSolver	(	std::string	object_name,
		SNES	petsc_snes
	)

Constructor for a concrete NewtonKrylovSolver that acts as a "wrapper" for a supplied PETSc SNES object.

Parameters

object_name	Name of the solver
petsc_snes	PETSc SNES object

Note: This constructor initializes a PETScNewtonKrylovSolver object that acts as a "wrapper" for the provided SNES object. Note that memory management of the provided SNES object is NOT handled by this class.

Member Function Documentation

◆ deallocateSolverState()

void IBTK::PETScNewtonKrylovSolver::deallocateSolverState ( )

overridevirtual

Remove all hierarchy dependent data allocated by initializeSolverState().

When any operator objects have been registered with this class via setOperator() or setJacobian(), they are also deallocated by this member function.

Note: It is safe to call deallocateSolverState() when the solver state is already deallocated.

See also: initializeSolverState

Reimplemented from IBTK::GeneralSolver.

◆ initializeSolverState()

void IBTK::PETScNewtonKrylovSolver::initializeSolverState	(	const SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &	x,
		const SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &	b
	)

overridevirtual

Compute hierarchy dependent data required for solving $F[x]=b$ .

By default, the solveSystem() method computes some required hierarchy dependent data before solving and removes that data after the solve. For multiple solves that use the same hierarchy configuration, it is more efficient to:

initialize the hierarchy-dependent data required by the solver via initializeSolverState(),
solve the system one or more times via solveSystem(), and
remove the hierarchy-dependent data via deallocateSolverState().

Note that it is generally necessary to reinitialize the solver state when the hierarchy configuration changes.

When any operator objects have been registered with this class via setOperator() or setJacobian(), they are also initialized by this member function.

Parameters

x	solution vector
b	right-hand-side vector

Conditions on Parameters:

vectors x and b must have same patch hierarchy
vectors x and b must have same structure, depth, etc.

Note: The vector arguments for solveSystem() need not match those for initializeSolverState(). However, there must be a certain degree of similarity, including:

hierarchy configuration (hierarchy pointer and range of levels)
number, type and alignment of vector component data
ghost cell widths of data in the solution x and right-hand-side b vectors

Note: It is safe to call initializeSolverState() when the state is already initialized. In this case, the solver state is first deallocated and then reinitialized.

See also: deallocateSolverState

Reimplemented from IBTK::GeneralSolver.

◆ setJacobian()

void IBTK::PETScNewtonKrylovSolver::setJacobian ( SAMRAI::tbox::Pointer< JacobianOperator > J )

overridevirtual

Set the Jacobian operator $J[x] = F'[x]$ used by the solver.

Note: If a Jacobian object is not explicitly provided to the solver, a Jacobian-free inexact Newton-Krylov method is employed to approximate the action of the Jacobian.

Reimplemented from IBTK::NewtonKrylovSolver.

◆ solveSystem()

bool IBTK::PETScNewtonKrylovSolver::solveSystem	(	SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &	x,
		SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &	b
	)

overridevirtual

Solve the system $F[x]=b$ for $x$ .

Before calling solveSystem(), the form of the solution x and right-hand-side b vectors must be set properly by the user on all patch interiors on the specified range of levels in the patch hierarchy. The user is responsible for all data management for the quantities associated with the solution and right-hand-side vectors. In particular, patch data in these vectors must be allocated prior to calling this method.

Parameters

x	solution vector
b	right-hand-side vector

Conditions on Parameters:

vectors x and b must have same patch hierarchy
vectors x and b must have same structure, depth, etc.

Note: The vector arguments for solveSystem() need not match those for initializeSolverState(). However, there must be a certain degree of similarity, including:

hierarchy configuration (hierarchy pointer and range of levels)
number, type and alignment of vector component data
ghost cell widths of data in the solution x and right-hand-side b vectors

Note: The solver need not be initialized prior to calling solveSystem(); however, see initializeSolverState() and deallocateSolverState() for opportunities to save overhead when performing multiple consecutive solves.

See also: initializeSolverState; deallocateSolverState

Returns: true if the solver converged to the specified tolerances, false otherwise

Implements IBTK::GeneralSolver.

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

/home/runner/work/IBAMR/IBAMR/ibtk/include/ibtk/PETScNewtonKrylovSolver.h
/home/runner/work/IBAMR/IBAMR/ibtk/src/solvers/impls/PETScNewtonKrylovSolver.cpp

Public Member Functions

Static Public Member Functions

Newton-Krylov solver functionality.

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ PETScNewtonKrylovSolver()

Member Function Documentation

◆ deallocateSolverState()

◆ initializeSolverState()

◆ setJacobian()

◆ solveSystem()