IBAMR
An adaptive and distributed-memory parallel implementation of the immersed boundary (IB) method
Public Member Functions | List of all members
IBTK::FACPreconditioner Class Reference

Class FACPreconditioner is a concrete LinearSolver for implementing FAC (multilevel multigrid) preconditioners. More...

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

Inheritance diagram for IBTK::FACPreconditioner:
Inheritance graph
[legend]

Public Member Functions

 FACPreconditioner (std::string object_name, SAMRAI::tbox::Pointer< FACPreconditionerStrategy > fac_strategy, SAMRAI::tbox::Pointer< SAMRAI::tbox::Database > input_db, const std::string &default_options_prefix)
 
 ~FACPreconditioner ()
 
Linear solver functionality.
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.
 
bool solveSystem (SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &x, SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &b) override
 Solve the linear system of equations $Ax=b$ for $x$. 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 $Ax=b$. More...
 
void deallocateSolverState () override
 Remove all hierarchy dependent data allocated by initializeSolverState(). More...
 
- Public Member Functions inherited from IBTK::LinearSolver
 LinearSolver ()
 Constructor.
 
virtual ~LinearSolver ()
 Empty virtual destructor.
 
virtual void setNullspace (bool nullspace_contains_constant_vec, const std::vector< SAMRAI::tbox::Pointer< SAMRAI::solv::SAMRAIVectorReal< NDIM, double > > > &nullspace_basis_vecs=std::vector< SAMRAI::tbox::Pointer< SAMRAI::solv::SAMRAIVectorReal< NDIM, double > > >())
 Set the nullspace of the linear system. More...
 
virtual bool getNullspaceContainsConstantVector () const
 Get whether the nullspace of the linear system contains th constant vector.
 
virtual const std::vector< SAMRAI::tbox::Pointer< SAMRAI::solv::SAMRAIVectorReal< NDIM, double > > > & getNullspaceBasisVectors () const
 Get the basis vectors for the nullspace of the linear system.
 
virtual bool getInitialGuessNonzero () const
 Get whether the initial guess is non-zero.
 
virtual void printClassData (std::ostream &stream) override
 Print class data to stream.
 
- Public Member Functions inherited from IBTK::GeneralSolver
 GeneralSolver ()=default
 Constructor.
 
virtual ~GeneralSolver ()=default
 Empty virtual destructor.
 
const std::stringgetName () 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 void setHierarchyMathOps (SAMRAI::tbox::Pointer< HierarchyMathOps > hier_math_ops)
 Set the HierarchyMathOps object used by the solver.
 
virtual SAMRAI::tbox::Pointer< HierarchyMathOpsgetHierarchyMathOps () const
 Get the HierarchyMathOps object used by the solver.
 
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.
 

Functions to access solver parameters.

SAMRAI::tbox::Pointer< FACPreconditionerStrategyd_fac_strategy
 
SAMRAI::tbox::Pointer< SAMRAI::hier::PatchHierarchy< NDIM > > d_hierarchy
 
int d_coarsest_ln = 0
 
int d_finest_ln = 0
 
MGCycleType d_cycle_type = V_CYCLE
 
int d_num_pre_sweeps = 0
 
int d_num_post_sweeps = 2
 
void setInitialGuessNonzero (bool initial_guess_nonzero=true) override
 Set whether the initial guess is non-zero.
 
void setMaxIterations (int max_iterations) override
 Set the maximum number of iterations to use per solve.
 
void setMGCycleType (MGCycleType cycle_type)
 Set the multigrid algorithm cycle type.
 
MGCycleType getMGCycleType () const
 Get the multigrid algorithm cycle type.
 
void setNumPreSmoothingSweeps (int num_pre_sweeps)
 Set the number of pre-smoothing sweeps to employ.
 
int getNumPreSmoothingSweeps () const
 Get the number of pre-smoothing sweeps employed by the preconditioner.
 
void setNumPostSmoothingSweeps (int num_post_sweeps)
 Set the number of post-smoothing sweeps to employ.
 
int getNumPostSmoothingSweeps () const
 Get the number of post-smoothing sweeps employed by the preconditioner.
 
SAMRAI::tbox::Pointer< FACPreconditionerStrategygetFACPreconditionerStrategy () const
 Get the FAC preconditioner strategy objects employed by the preconditioner.
 
void FACVCycleNoPreSmoothing (SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &u, SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &f, int level_num)
 
void muCycle (SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &u, SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &f, SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &r, int level_num, int mu)
 
void FCycle (SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &u, SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &f, SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &r, int level_num)
 
void FMGCycle (SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &u, SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &f, SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &r, int level_num, int mu)
 

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::LinearSolver
bool d_initial_guess_nonzero = true
 
bool d_nullspace_contains_constant_vec = false
 
std::vector< SAMRAI::tbox::Pointer< SAMRAI::solv::SAMRAIVectorReal< NDIM, double > > > d_nullspace_basis_vecs
 
- 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< HierarchyMathOpsd_hier_math_ops
 
bool d_hier_math_ops_external = false
 
bool d_enable_logging = false
 

Detailed Description

Class FACPreconditioner is a concrete LinearSolver for implementing FAC (multilevel multigrid) preconditioners.

This class is similar to the SAMRAI class SAMRAI::solv::FACPreconditioner, except that this class has been optimized for the case in which the solver is to be used as a single-pass preconditioner, especially for the case in which pre-smoothing sweeps are not needed. This class is not suitable for use as a stand-alone solver; rather, it is intended to be used in conjunction with an iterative Krylov method.

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

cycle_type = "V_CYCLE"  // see setMGCycleType()
num_pre_sweeps = 0      // see setNumPreSmoothingSweeps()
num_post_sweeps = 2     // see setNumPostSmoothingSweeps()
enable_logging = FALSE  // see setLoggingEnabled()

Constructor & Destructor Documentation

◆ FACPreconditioner()

IBTK::FACPreconditioner::FACPreconditioner ( std::string  object_name,
SAMRAI::tbox::Pointer< FACPreconditionerStrategy fac_strategy,
SAMRAI::tbox::Pointer< SAMRAI::tbox::Database input_db,
const std::string default_options_prefix 
)

Constructor.

◆ ~FACPreconditioner()

IBTK::FACPreconditioner::~FACPreconditioner ( )

Destructor.

Member Function Documentation

◆ deallocateSolverState()

void IBTK::FACPreconditioner::deallocateSolverState ( )
overridevirtual

Remove all hierarchy dependent data allocated by initializeSolverState().

When linear operator or preconditioner objects have been registered with this class via setOperator() and setPreconditioner(), 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::FACPreconditioner::initializeSolverState ( const SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &  x,
const SAMRAI::solv::SAMRAIVectorReal< NDIM, double > &  b 
)
overridevirtual

Compute hierarchy dependent data required for solving $Ax=b$.

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:

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

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

When linear operator or preconditioner objects have been registered with this class via setOperator() and setPreconditioner(), they are also initialized by this member function.

Parameters
xsolution vector
bright-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.

◆ solveSystem()

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

Solve the linear system of equations $Ax=b$ 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
xsolution vector
bright-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: