peclet::core::solver::AndersonCore Class Reference

#include <anderson.hpp>

Public Types
enum class	Status : int { Active = 0 , Disabled = 1 }

Public Member Functions
	AndersonCore (AndersonState state, int window=5, double mixing=1.0)
	Allocates the history (design §6.3: (2m+3)·n_s·8·n_pad bytes).
	AndersonCore (const AndersonCore &)=delete
AndersonCore &	operator= (const AndersonCore &)=delete
	AndersonCore (AndersonCore &&)=default
AndersonCore &	operator= (AndersonCore &&)=default
bool	prepare (bool accelerate)
	§4.3 steps 0–1.
bool	stepFailed (const std::string &what)
	§4.3 step 2, the caller's step threw.
void	complete (bool pressureSolveFailed=false)
	§4.3 steps 3–7, after the caller's step.
void	reset ()
	Clears the history and the counters (design §4.2); keeps the previous evaluation, so the next call forms a column at once.
void	invalidate ()
	The caller's map changed (flow: its parameter signature) or the state was written: reset() and forget the previous evaluation; counts in numResets().
void	disable ()
	Stops acceleration for good: prepare/complete become no-ops around a plain step.
Status	status () const
const char *	statusName () const
	"active" | "disabled".
const std::string &	reason () const
double	residual () const
	Relative velocity residual of the last evaluation whose output the state holds (design §3.2; after a restart, the restored output's); +inf before the first.
int	numRestarts () const
int	numResets () const
int	numColumns () const
	Window columns in use (mk).
int	window () const
double	mixing () const
bool	engaged () const
bool	pending () const
	A mix is pending for the next accelerated call.
std::vector< double >	gamma () const
	The pending coefficients γ, oldest column first (numColumns() of them).
std::size_t	memoryBytes () const
	Bytes held by the history, X, Rprev and Gprev: equals memoryBytesFor(window(), n_s, n_pad).
const AndersonState &	state () const

Static Public Member Functions
static std::size_t	memoryBytesFor (int window, std::size_t numFields, Index nPad)
	The §6.3 memory formula: (2m + 3)·n_s·8·n_pad bytes.

Static Public Attributes
static constexpr int	kMaxWindow = detail::anderson::kMaxWindow
static constexpr int	kEngageDecreases = 2
static constexpr double	kRestartGrowth = 4.0
static constexpr int	kMaxRestarts = 5
static constexpr double	kNoiseFloor = 1e-10
static constexpr double	kCondMin = 1e-12

Detailed Description

Definition at line 329 of file anderson.hpp.

Member Enumeration Documentation

Status

enum class peclet::core::solver::AndersonCore::Status : int

strong

Enumerator
Active
Disabled

Definition at line 342 of file anderson.hpp.

Constructor & Destructor Documentation

AndersonCore() [1/3]

peclet::core::solver::AndersonCore::AndersonCore ( AndersonState  state, int  window = 5, double  mixing = 1.0  )

inlineexplicit

Allocates the history (design §6.3: (2m+3)·n_s·8·n_pad bytes).

Collective over state.comm (one 2-double sum {invalid descriptor, failed allocation}, so that every rank throws when one rank's descriptor is inconsistent or one rank's allocation fails). Throws std::invalid_argument (on every rank) for an inconsistent descriptor and std::runtime_error (on every rank) when the history does not fit.

Definition at line 349 of file anderson.hpp.

References peclet::core::solver::AndersonState::fields, and memoryBytesFor().

AndersonCore() [2/3]

peclet::core::solver::AndersonCore::AndersonCore ( const AndersonCore &  )

delete

AndersonCore() [3/3]

peclet::core::solver::AndersonCore::AndersonCore ( AndersonCore &&  )

default

Member Function Documentation

operator=() [1/2]

AndersonCore & peclet::core::solver::AndersonCore::operator= ( const AndersonCore &  )

delete

operator=() [2/2]

AndersonCore & peclet::core::solver::AndersonCore::operator= ( AndersonCore &&  )

default

memoryBytesFor()

static std::size_t peclet::core::solver::AndersonCore::memoryBytesFor ( int  window, std::size_t  numFields, Index  nPad  )

inlinestatic

The §6.3 memory formula: (2m + 3)·n_s·8·n_pad bytes.

Definition at line 406 of file anderson.hpp.

References window().

Referenced by AndersonCore().

prepare()

bool peclet::core::solver::AndersonCore::prepare ( bool  accelerate )

inline

§4.3 steps 0–1.

Detects an external write of the state (inner entries only), then either applies the pending mix (accelerate, pending, active) or records the input. Returns whether the state now holds a mixed iterate. Collective (one 1-double sum) while active; one host synchronisation (the COUNT read-back).

Definition at line 417 of file anderson.hpp.

References Active, peclet::core::solver::detail::anderson::MixColumns::count, peclet::core::solver::detail::anderson::countChanged(), peclet::core::solver::AndersonState::extent, peclet::core::solver::AndersonState::fields, peclet::core::solver::AndersonState::ghost, invalidate(), and peclet::core::solver::detail::anderson::mix().

stepFailed()

bool peclet::core::solver::AndersonCore::stepFailed ( const std::string &  what )

inline

§4.3 step 2, the caller's step threw.

Returns true when the failure was absorbed: the input was a mixed iterate, so the state is restored to the last map output, acceleration is disabled and the caller continues (plain). Returns false when the caller must rethrow.

Definition at line 461 of file anderson.hpp.

References Active, peclet::core::solver::AndersonState::comm, Disabled, peclet::core::solver::AndersonComm::rank, and reset().

complete()

void peclet::core::solver::AndersonCore::complete ( bool  pressureSolveFailed = false )

inline

§4.3 steps 3–7, after the caller's step.

pressureSolveFailed must be rank-consistent. Collective while active: a (2·columns + 2)-double sum and a broadcast of rank 0's decisions; one host synchronisation (the pass-2 read-back). The device copies are stream-ordered.

Definition at line 480 of file anderson.hpp.

References Active, Disabled, peclet::core::solver::AndersonState::extent, peclet::core::solver::AndersonState::fields, peclet::core::solver::AndersonState::ghost, kCondMin, kEngageDecreases, kMaxRestarts, kMaxWindow, kNoiseFloor, kRestartGrowth, reset(), peclet::core::solver::AndersonState::roles, and peclet::core::solver::Velocity.

reset()

void peclet::core::solver::AndersonCore::reset ( )

inline

Clears the history and the counters (design §4.2); keeps the previous evaluation, so the next call forms a column at once.

Definition at line 638 of file anderson.hpp.

Referenced by complete(), invalidate(), and stepFailed().

invalidate()

void peclet::core::solver::AndersonCore::invalidate ( )

inline

The caller's map changed (flow: its parameter signature) or the state was written: reset() and forget the previous evaluation; counts in numResets().

Definition at line 647 of file anderson.hpp.

References reset().

Referenced by prepare().

disable()

void peclet::core::solver::AndersonCore::disable ( )

inline

Stops acceleration for good: prepare/complete become no-ops around a plain step.

Definition at line 654 of file anderson.hpp.

References Active, and Disabled.

status()

Status peclet::core::solver::AndersonCore::status ( ) const

inline

Definition at line 665 of file anderson.hpp.

statusName()

const char * peclet::core::solver::AndersonCore::statusName ( ) const

inline

"active" | "disabled".

Definition at line 667 of file anderson.hpp.

References Active.

reason()

const std::string & peclet::core::solver::AndersonCore::reason ( ) const

inline

Definition at line 668 of file anderson.hpp.

residual()

double peclet::core::solver::AndersonCore::residual ( ) const

inline

Relative velocity residual of the last evaluation whose output the state holds (design §3.2; after a restart, the restored output's); +inf before the first.

Definition at line 671 of file anderson.hpp.

numRestarts()

int peclet::core::solver::AndersonCore::numRestarts ( ) const

inline

Definition at line 672 of file anderson.hpp.

numResets()

int peclet::core::solver::AndersonCore::numResets ( ) const

inline

Definition at line 673 of file anderson.hpp.

numColumns()

int peclet::core::solver::AndersonCore::numColumns ( ) const

inline

Window columns in use (mk).

Definition at line 675 of file anderson.hpp.

window()

int peclet::core::solver::AndersonCore::window ( ) const

inline

Definition at line 676 of file anderson.hpp.

Referenced by memoryBytesFor().

mixing()

double peclet::core::solver::AndersonCore::mixing ( ) const

inline

Definition at line 677 of file anderson.hpp.

engaged()

bool peclet::core::solver::AndersonCore::engaged ( ) const

inline

Definition at line 678 of file anderson.hpp.

pending()

bool peclet::core::solver::AndersonCore::pending ( ) const

inline

A mix is pending for the next accelerated call.

Definition at line 680 of file anderson.hpp.

gamma()

std::vector< double > peclet::core::solver::AndersonCore::gamma ( ) const

inline

The pending coefficients γ, oldest column first (numColumns() of them).

Definition at line 682 of file anderson.hpp.

memoryBytes()

std::size_t peclet::core::solver::AndersonCore::memoryBytes ( ) const

inline

Bytes held by the history, X, Rprev and Gprev: equals memoryBytesFor(window(), n_s, n_pad).

Definition at line 684 of file anderson.hpp.

References peclet::core::add().

state()

const AndersonState & peclet::core::solver::AndersonCore::state ( ) const

inline

Definition at line 699 of file anderson.hpp.

Member Data Documentation

kMaxWindow

constexpr int peclet::core::solver::AndersonCore::kMaxWindow = detail::anderson::kMaxWindow

staticconstexpr

Definition at line 332 of file anderson.hpp.

Referenced by complete().

kEngageDecreases

constexpr int peclet::core::solver::AndersonCore::kEngageDecreases = 2

staticconstexpr

Definition at line 333 of file anderson.hpp.

Referenced by complete().

kRestartGrowth

constexpr double peclet::core::solver::AndersonCore::kRestartGrowth = 4.0

staticconstexpr

Definition at line 334 of file anderson.hpp.

Referenced by complete().

kMaxRestarts

constexpr int peclet::core::solver::AndersonCore::kMaxRestarts = 5

staticconstexpr

Definition at line 335 of file anderson.hpp.

Referenced by complete().

kNoiseFloor

constexpr double peclet::core::solver::AndersonCore::kNoiseFloor = 1e-10

staticconstexpr

Definition at line 336 of file anderson.hpp.

Referenced by complete().

kCondMin

constexpr double peclet::core::solver::AndersonCore::kCondMin = 1e-12

staticconstexpr

Definition at line 337 of file anderson.hpp.

Referenced by complete().

---

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

• anderson.hpp