#include <BALL/MOLMEC/MINIMIZATION/strangLBFGS.h>

Inheritance diagram for BALL::StrangLBFGSMinimizer:

Classes
struct	Default

struct	Option

Public Member Functions
Constructors and Destructors
	StrangLBFGSMinimizer ()

	StrangLBFGSMinimizer (ForceField &force_field)

	StrangLBFGSMinimizer (ForceField &force_field, SnapShotManager *ssm)

	StrangLBFGSMinimizer (ForceField &force_field, SnapShotManager *ssm, const Options &options)

	StrangLBFGSMinimizer (ForceField &force_field, const Options &options)

	StrangLBFGSMinimizer (const StrangLBFGSMinimizer &rhs)

virtual	~StrangLBFGSMinimizer ()

Assignments
const StrangLBFGSMinimizer &	operator= (const StrangLBFGSMinimizer &rhs)

Setup methods. They do all necessary preparations.
virtual bool	specificSetup ()

Accessors
void	setMaxNumOfStoredVectPairs (Size num)

Size	getMaxNumOfStoredVectPairs () const

void	setImprovedFlag (bool flag)

bool	getImprovedFlag () const

virtual double	findStep ()

virtual void	updateDirection ()

virtual bool	minimize (Size iterations=0, bool resume=false)

Public Member Functions inherited from BALL::EnergyMinimizer
bool	operator== (const EnergyMinimizer &energy_minimizer)

	EnergyMinimizer ()

	EnergyMinimizer (ForceField &force_field)

	EnergyMinimizer (ForceField &force_field, const Options &options)

	EnergyMinimizer (const EnergyMinimizer &energy_minimizer)

virtual	~EnergyMinimizer ()

const EnergyMinimizer &	operator= (const EnergyMinimizer &energy_minimizer)

bool	isValid () const

bool	setup (ForceField &force_field)

bool	setup (ForceField &force_field, SnapShotManager *ssm)

bool	setup (ForceField &force_field, SnapShotManager *ssm, const Options &options)

bool	setup (ForceField &force_field, const Options &options)

virtual bool	isConverged () const

virtual double	updateEnergy ()

virtual void	updateForces ()

void	storeGradientEnergy ()

virtual void	printEnergy () const

virtual void	takeSnapShot () const

virtual void	finishIteration ()

Size	getNumberOfIterations () const

Gradient &	getDirection ()

Gradient &	getGradient ()

Gradient &	getInitialGradient ()

double	getEnergy () const

double &	getEnergy ()

double	getInitialEnergy () const

double &	getInitialEnergy ()

void	setNumberOfIterations (Size number_of_iterations)

Size	getMaxNumberOfIterations () const

void	setMaxNumberOfIterations (Size number_of_iterations)

void	setMaxSameEnergy (Size number)

Size	getMaxSameEnergy () const

void	setEnergyOutputFrequency (Size energy_output_frequency)

Size	getEnergyOutputFrequency () const

void	setEnergyDifferenceBound (float energy_difference_bound)

float	getEnergyDifferenceBound () const

void	setMaxGradient (float max_gradient)

float	getMaxGradient () const

void	setMaximumDisplacement (float maximum_displacement)

float	getMaximumDisplacement () const

void	setSnapShotFrequency (Size snapshot_frequency)

Size	getSnapShotFrequency () const

ForceField *	getForceField ()

Size	getForceUpdateCounter () const

Size	getEnergyUpdateCounter () const

void	enableEnergyAbortCondition (bool state)

bool	energyAbortConditionEnabled () const
	Query if the MDSimulation aborts if the Energy is greater than abort_energy_. More...

void	setEnergyToAbort (float value)

float	getEnergyToAbort () const

bool	wasAborted () const

Protected Attributes
Protected Attributes
LineSearch	line_search_

bool	first_iter_

Size	number_of_atoms_

Size	max_num_of_vect_pairs_

Size	curr_num_of_vect_pairs_

bool	improved_

vector< float >	rho_

vector< Vector3 >	stored_s_

vector< Vector3 >	stored_y_

vector< float >	work_val_

Size	index_of_free_vect_

std::vector< Vector3 >	initial_atoms_

Protected Attributes inherited from BALL::EnergyMinimizer
Gradient	initial_grad_

Gradient	current_grad_

double	initial_energy_

double	current_energy_

Gradient	old_grad_

double	old_energy_

Gradient	direction_

bool	valid_

SnapShotManager *	snapshot_

ForceField *	force_field_

Size	number_of_iterations_

Size	maximal_number_of_iterations_

Size	energy_output_frequency_

Size	snapshot_frequency_

double	energy_difference_bound_

double	max_gradient_

Size	max_same_energy_

Size	same_energy_counter_

float	maximum_displacement_

Size	force_update_counter_

Size	energy_update_counter_

float	cutlo_

double	step_

bool	abort_by_energy_enabled_

float	abort_energy_

bool	aborted_

Additional Inherited Members
Public Attributes inherited from BALL::EnergyMinimizer
Options	options

Detailed Description

Limited-memory BFGS minimizer based on the Strang recurrence. A minimizer for geometry optimization based on the limited-memory BFGS method proposed in

[1] Nocedal J.: Updating quasi-Newton matrices with limited storage. Math. Comp. 35 (1980) 773-782.

[2] Liu D.C., Nocedal J.: On the limited memory BFGS method for large scale optimization. Math. Programming 45 (1989) 503-528.

If the 'improved' option is set, ideas proposed in

[3] Mehiddin Al-Baali: Improved Hessian approximations for the limited memory BFGS method. Numerical Algorithms 22 (1999) 99-112

are adopted.

Definition at line 38 of file strangLBFGS.h.

Constructor & Destructor Documentation

BALL::StrangLBFGSMinimizer::StrangLBFGSMinimizer ( )

Default constructor.

BALL::StrangLBFGSMinimizer::StrangLBFGSMinimizer ( ForceField & force_field )

Constructor expecting a valid force field

BALL::StrangLBFGSMinimizer::StrangLBFGSMinimizer	(	ForceField &	force_field,
		SnapShotManager *	ssm
	)

Constructor expecting a valid force field and a snapshot manager

BALL::StrangLBFGSMinimizer::StrangLBFGSMinimizer	(	ForceField &	force_field,
		SnapShotManager *	ssm,
		const Options &	options
	)

Constructor expecting a valid force field, a snapshot manager and options

BALL::StrangLBFGSMinimizer::StrangLBFGSMinimizer	(	ForceField &	force_field,
		const Options &	options
	)

Constructor expecting a valid force field and options

BALL::StrangLBFGSMinimizer::StrangLBFGSMinimizer ( const StrangLBFGSMinimizer & rhs )

Copy constructor

virtual BALL::StrangLBFGSMinimizer::~StrangLBFGSMinimizer ( )

virtual

Destructor.

Member Function Documentation

virtual double BALL::StrangLBFGSMinimizer::findStep ( )

virtual

Calculate the next step. First, this method updates the model. Second, it performs a line search along the calculated direction afterwards.

Returns: double $\geq 0$ if the line search found an acceptable solution, otherwise -1.

See also: EnergyMinimizer::findStep

Reimplemented from BALL::EnergyMinimizer.

bool BALL::StrangLBFGSMinimizer::getImprovedFlag ( ) const

Return the improved flag

Size BALL::StrangLBFGSMinimizer::getMaxNumOfStoredVectPairs ( ) const

Return the maximum number of stored vector pairs

virtual bool BALL::StrangLBFGSMinimizer::minimize	(	Size	iterations = `0`,
		bool	resume = `false`
	)

virtual

Minimize the energy of the system. This method executes at most iterations minimization steps. If the number of iterations is not given, the number specified in the options is taken.

Parameters

iterations	the maximum number of iterations
resume	true to resume a previous run

See also: EnergyMinimizer::minimize

Reimplemented from BALL::EnergyMinimizer.

const StrangLBFGSMinimizer& BALL::StrangLBFGSMinimizer::operator= ( const StrangLBFGSMinimizer & rhs )

Assignment operator

void BALL::StrangLBFGSMinimizer::setImprovedFlag ( bool flag )

Set the improved flag

void BALL::StrangLBFGSMinimizer::setMaxNumOfStoredVectPairs ( Size num )

Set the maximum number of stored vector pairs

virtual bool BALL::StrangLBFGSMinimizer::specificSetup ( )

virtual

Specific setup

Reimplemented from BALL::EnergyMinimizer.

virtual void BALL::StrangLBFGSMinimizer::updateDirection ( )

virtual

Update the stored vector pairs, either by adding a new pair or if there is no space left by replacing the oldest pair. Compute the search direction afterwards by using the Strang recurrence formula (optional: with an improvement idea of Al-Baali).

Reimplemented from BALL::EnergyMinimizer.

Member Data Documentation

Size BALL::StrangLBFGSMinimizer::curr_num_of_vect_pairs_

protected

Current number of stored vector pairs.

Definition at line 200 of file strangLBFGS.h.

bool BALL::StrangLBFGSMinimizer::first_iter_

protected

Is this an initial first iteration?

Definition at line 188 of file strangLBFGS.h.

bool BALL::StrangLBFGSMinimizer::improved_

protected

Should the improved version be used?

Definition at line 204 of file strangLBFGS.h.

Size BALL::StrangLBFGSMinimizer::index_of_free_vect_

protected

Index of the vector pair which will be used for saving the data of the current step (usually by replacing old data).

Definition at line 227 of file strangLBFGS.h.

std::vector<Vector3> BALL::StrangLBFGSMinimizer::initial_atoms_

protected

Positions of movable atoms when starting an iteration. This is used to reduce slightly rounding errors

Definition at line 232 of file strangLBFGS.h.

LineSearch BALL::StrangLBFGSMinimizer::line_search_

protected

The line search

Definition at line 184 of file strangLBFGS.h.

Size BALL::StrangLBFGSMinimizer::max_num_of_vect_pairs_

protected

Maximum number of stored vector pairs.

Definition at line 196 of file strangLBFGS.h.

Size BALL::StrangLBFGSMinimizer::number_of_atoms_

protected

Number of movable atoms.

Definition at line 192 of file strangLBFGS.h.

vector<float> BALL::StrangLBFGSMinimizer::rho_

protected

Old and new scaling values. Also used in the Strang recurrence formula.

Definition at line 208 of file strangLBFGS.h.

vector<Vector3> BALL::StrangLBFGSMinimizer::stored_s_

protected

Stored former steps. Vectors stored in column order.

Definition at line 212 of file strangLBFGS.h.

vector<Vector3> BALL::StrangLBFGSMinimizer::stored_y_

protected

Stored former changes in gradients. Vectors stored in column order.

Definition at line 217 of file strangLBFGS.h.

vector<float> BALL::StrangLBFGSMinimizer::work_val_

protected

Temporarily used memory for saving scalars associated with the stored vector pairs.

Definition at line 222 of file strangLBFGS.h.

Classes

Public Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation