BALL::ShiftedLVMMMinimizer Class Reference
[Energy Minimizer]

Shifted limited-memory variable metric methods minimizer. More...

#include <shiftedLVMM.h>

Inheritance diagram for BALL::ShiftedLVMMMinimizer:

[legend]

List of all members.

Classes
struct	Option
	Symbolic names for option keys. More...
Public Types
Enums
enum	UpdateMethod { RANK_1 = 1, RANK_2 = 2 }
	The different variationally derived methods implemented. More...
enum	CorrectionParameter { UNIT_VALUE = 1, BALANCING_VALUE = 2, SQUARE_ROOT = 3, GEOMETRIC_MEAN = 4, RATIO_OF_SHIFT_PARAMS = 5 }
	The different correction parameters implemented. More...
Public Member Functions
Constructors and Destructors
	ShiftedLVMMMinimizer ()
	Default constructor.
	ShiftedLVMMMinimizer (ForceField &force_field)
	Constructor expecting a valid force field.
	ShiftedLVMMMinimizer (ForceField &force_field, SnapShotManager *ssm)
	Constructor expecting a valid force field and a snapshot manager.
	ShiftedLVMMMinimizer (ForceField &force_field, SnapShotManager *ssm, const Options &options)
	Constructor expecting a valid force field, a snapshot manager and options.
	ShiftedLVMMMinimizer (ForceField &force_field, const Options &options)
	Constructor expecting a valid force field and options.
	ShiftedLVMMMinimizer (const ShiftedLVMMMinimizer &rhs)
	Copy constructor.
virtual	~ShiftedLVMMMinimizer ()
	Destructor.
Assignments
const ShiftedLVMMMinimizer &	operator= (const ShiftedLVMMMinimizer &rhs)
	Assignment operator.
Setup methods. They do all necessary preparations.
virtual bool	specificSetup ()
	Specific setup.
Accessors
void	setUpdateMethod (UpdateMethod updt)
	Set explicitly the update method.
UpdateMethod	getUpdateMethod () const
	Return the update method.
void	setCorrectionParameter (CorrectionParameter corr)
	Set explicitly the correction parameter.
CorrectionParameter	getCorrectionParameter () const
	Return the correction parameter.
void	setMaxNumOfColumns (Size num)
	Set explicitly the maximum number of columns of the factor of the shifted inverse hessian approximation.
Size	getMaxNumOfColumns () const
	Return the maximum number of columns of the factor of the shifted inverse hessian approximation.
virtual double	findStep ()
	Calculate the next step.
virtual void	updateDirection ()
	Update the shifted inverse hessian approximation.
virtual bool	minimize (Size iterations=0, bool resume=false)
	Minimize the energy of the system.
Protected Attributes
Protected Attributes
LineSearch	line_search_
	The line search.
bool	first_iter_
	Is this an initial first iteration?
Size	number_of_atoms_
	Number of movable atoms.
Size	max_number_of_cols_
	Maximum number of columns of the factor of the shifted inverse hessian approximation.
Size	curr_number_of_cols_
	Current number of columns of the factor of the shifted inverse hessian approximation.
Size	updt_method_
	Update method.
Size	corr_par_
	Correction parameter.
double	prev_shift_val_
	Shift value of the previous iteration.
vector< Vector3 >	shift_s_
	Shifted previous step.
vector< Vector3 >	grad_diff_
	Current gradient difference.
vector< float >	updt_u_
	Needed vector for the update.
vector< float >	updt_v_
	Needed vector for the update.
vector< Vector3 >	shifted_direction_
	Direction of the shifted step, i. e. .
vector< Vector3 >	hess_factor_
	Factor of the shifted inverse hessian approximation in column order, in [3].
vector< Vector3 >	initial_atoms_
	Positions of the movable atoms when we start an iteration.

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Detailed Description

Shifted limited-memory variable metric methods minimizer.

A minimizer for geometry optimization based upon the shifted limited-memory variable metric methods proposed in

[1] Vlcek J., Luksan L.. New variable metric methods for unconstrained minimization covering the large-scale case. Report V-876, Prague, ICS AS CR, 2002.

[2] Vlcek J., Luksan L.. Additional properties of shifted variable metric methods. Report V-899, Prague, ICS AS CR, 2004.

[3] Vlcek J., Luksan L.. Shifted limited-memory variable metric methods for large-scale unconstrained optimization. Journal of Computational and Applied Mathematics 186 (2), pp. 365-390.

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Member Enumeration Documentation

enum BALL::ShiftedLVMMMinimizer::CorrectionParameter

The different correction parameters implemented.

Enumerator:

UNIT_VALUE	Unit value, i.e. rho = 1.0.
BALANCING_VALUE	Balancing value.
SQUARE_ROOT	Square root.
GEOMETRIC_MEAN	Geometric mean.
RATIO_OF_SHIFT_PARAMS	Ratio of shift parameters.

enum BALL::ShiftedLVMMMinimizer::UpdateMethod

The different variationally derived methods implemented.

Enumerator:

RANK_1	Rank 1 variationally derived method.
RANK_2	Rank 2 variationally derived method.

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Member Function Documentation

virtual double BALL::ShiftedLVMMMinimizer::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 if the line search found an acceptable solution, otherwise -1.

See also:

EnergyMinimizer::findStep

Reimplemented from BALL::EnergyMinimizer.

virtual bool BALL::ShiftedLVMMMinimizer::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.

virtual void BALL::ShiftedLVMMMinimizer::updateDirection

(

)

[virtual]

Update the shifted inverse hessian approximation.

Afterwards, compute the search direction.

Reimplemented from BALL::EnergyMinimizer.

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Member Data Documentation

vector<Vector3> BALL::ShiftedLVMMMinimizer::initial_atoms_ [protected]

Positions of the movable atoms when we start an iteration.

This is used to reduce slightly rounding errors