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BALL::ConjugateGradientMinimizer Class Reference

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

Inheritance diagram for BALL::ConjugateGradientMinimizer:
BALL::EnergyMinimizer

Classes

struct  Default
struct  Option

Public Types

Enums
enum  UpdateMethod { POLAK_RIBIERE = 1, FLETCHER_REEVES = 2, SHANNO = 3 }

Public Member Functions

Constructors and Destructors
 ConjugateGradientMinimizer ()
 ConjugateGradientMinimizer (ForceField &force_field)
 ConjugateGradientMinimizer (ForceField &force_field, SnapShotManager *ssm)
 ConjugateGradientMinimizer (ForceField &force_field, SnapShotManager *ssm, const Options &options)
 ConjugateGradientMinimizer (ForceField &force_field, const Options &options)
 ConjugateGradientMinimizer (const ConjugateGradientMinimizer &rhs)
virtual ~ConjugateGradientMinimizer ()
Assignments
const ConjugateGradientMinimizeroperator= (const ConjugateGradientMinimizer &rhs)
Setup methods. They do all necessary preparations.
virtual bool specificSetup ()
Accessors
void setUpdateMethod (UpdateMethod method)
UpdateMethod getUpdateMethod () 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 EnergyMinimizeroperator= (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
GradientgetDirection ()
GradientgetGradient ()
GradientgetInitialGradient ()
double getEnergy () const
doublegetEnergy ()
double getInitialEnergy () const
doublegetInitialEnergy ()
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
ForceFieldgetForceField ()
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_.
void setEnergyToAbort (float value)
float getEnergyToAbort () const
bool wasAborted () const

Protected Attributes

Protected Attributes
LineSearch line_search_
Gradient unscaled_direction_
Size number_of_atoms_
Size updt_method_
bool first_iter_
double old_gtg_
vector< Vector3a_i_
vector< Vector3b_i_
vector< Vector3p_t_
vector< Vector3y_t_
vector< Vector3p_i_
vector< Vector3y_i_
double D_1_
double D_4_
Size restart_frequency_
Size last_restart_iter_
- 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_
SnapShotManagersnapshot_
ForceFieldforce_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

A minimizer for geometry optimization based on different conjugate gradient (CG) algorithms. See

[1] Fletcher, R. and Reeves, C.M. "Function Minimization by Conjugate Gradients" Comp. J., 7, 149-154, 1964

[2] David Shanno "Conjugate Gradient Methods With Inexact Searches" Mathematics of Operations Research, Vol. 3, No. 3, August 1978, pp. 244-256

[3] S. Watowich et. al "A Stable Rapidly Converging Conjugate Gradient Method for Energy Minimization" Journal of Computational Chemistry, Vol. 9, No. 6, pp. 650-661 (1988)

[4] M.J.D. Powell "Convergence properties of algorithms for nonlinear optimization" Report No. DAMPT 1985/NA1, University of Cambridge, 1985

[5] D.F. Shanno "Globally convergent conjugate gradient algorithms" Mathematical Programming 33 (1985), pp. 61-67

Definition at line 40 of file conjugateGradient.h.

Member Enumeration Documentation

The different conjugate gradient methods implemented.

See Also
updateDirection for details on the implementation and references
Enumerator:
POLAK_RIBIERE 

Polak-Ribiere method

FLETCHER_REEVES 

Fletcher-Reeves method

SHANNO 

Shanno

Definition at line 52 of file conjugateGradient.h.

Constructor & Destructor Documentation

BALL::ConjugateGradientMinimizer::ConjugateGradientMinimizer ( )

Default constructor.

BALL::ConjugateGradientMinimizer::ConjugateGradientMinimizer ( ForceField force_field)

Constructor expecting a valid force field

BALL::ConjugateGradientMinimizer::ConjugateGradientMinimizer ( ForceField force_field,
SnapShotManager ssm 
)

Constructor expecting a valid force field and a snapshot manager

BALL::ConjugateGradientMinimizer::ConjugateGradientMinimizer ( ForceField force_field,
SnapShotManager ssm,
const Options options 
)

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

BALL::ConjugateGradientMinimizer::ConjugateGradientMinimizer ( ForceField force_field,
const Options options 
)

Constructor expecting a valid force field and options

BALL::ConjugateGradientMinimizer::ConjugateGradientMinimizer ( const ConjugateGradientMinimizer rhs)

Copy constructor

virtual BALL::ConjugateGradientMinimizer::~ConjugateGradientMinimizer ( )
virtual

Destructor.

Member Function Documentation

virtual double BALL::ConjugateGradientMinimizer::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.

UpdateMethod BALL::ConjugateGradientMinimizer::getUpdateMethod ( ) const

Returns the current method for updateDirection.

virtual bool BALL::ConjugateGradientMinimizer::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
iterationsthe maximum number of iterations
resumetrue to resume a previous run
See Also
EnergyMinimizer::minimize

Reimplemented from BALL::EnergyMinimizer.

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

Assignment operator

void BALL::ConjugateGradientMinimizer::setUpdateMethod ( UpdateMethod  method)

Set explicitly the criterion used for updateDirection. If the method is not recognized, this function fails.

virtual bool BALL::ConjugateGradientMinimizer::specificSetup ( )
virtual

Specific setup

Reimplemented from BALL::EnergyMinimizer.

virtual void BALL::ConjugateGradientMinimizer::updateDirection ( )
virtual

Update the search direction. This method updates the search direction. It uses the different conjugate gradient caculations dependend on the options.

Reimplemented from BALL::EnergyMinimizer.

Member Data Documentation

vector<Vector3> BALL::ConjugateGradientMinimizer::a_i_
protected

Variable needed for the Shanno direction calculation

Definition at line 216 of file conjugateGradient.h.

vector<Vector3> BALL::ConjugateGradientMinimizer::b_i_
protected

Variable needed for the Shanno direction calculation

Definition at line 220 of file conjugateGradient.h.

double BALL::ConjugateGradientMinimizer::D_1_
protected

Variable needed for the Shanno direction calculation

Definition at line 240 of file conjugateGradient.h.

double BALL::ConjugateGradientMinimizer::D_4_
protected

Variable needed for the Shanno direction calculation

Definition at line 244 of file conjugateGradient.h.

bool BALL::ConjugateGradientMinimizer::first_iter_
protected

Is this the (initial) first iteration?

Definition at line 208 of file conjugateGradient.h.

Size BALL::ConjugateGradientMinimizer::last_restart_iter_
protected

We count the iterations since the last restart. There are other necessities for a restart so the iteration counter may not coincide (by modulo) with the restart frequency.

Definition at line 255 of file conjugateGradient.h.

LineSearch BALL::ConjugateGradientMinimizer::line_search_
protected

The line search

Definition at line 192 of file conjugateGradient.h.

Size BALL::ConjugateGradientMinimizer::number_of_atoms_
protected

Number of movable atoms.

Definition at line 200 of file conjugateGradient.h.

double BALL::ConjugateGradientMinimizer::old_gtg_
protected

$g^T \cdot g$ where $g$ is the gradient of the last iteration

Definition at line 212 of file conjugateGradient.h.

vector<Vector3> BALL::ConjugateGradientMinimizer::p_i_
protected

Variable needed for the Shanno direction calculation

Definition at line 232 of file conjugateGradient.h.

vector<Vector3> BALL::ConjugateGradientMinimizer::p_t_
protected

Variable needed for the Shanno direction calculation

Definition at line 224 of file conjugateGradient.h.

Size BALL::ConjugateGradientMinimizer::restart_frequency_
protected

Frequency for restarts.

Definition at line 248 of file conjugateGradient.h.

Gradient BALL::ConjugateGradientMinimizer::unscaled_direction_
protected

Unscaled last search direction

Definition at line 196 of file conjugateGradient.h.

Size BALL::ConjugateGradientMinimizer::updt_method_
protected

Update method used for the CG

Definition at line 204 of file conjugateGradient.h.

vector<Vector3> BALL::ConjugateGradientMinimizer::y_i_
protected

Variable needed for the Shanno direction calculation

Definition at line 236 of file conjugateGradient.h.

vector<Vector3> BALL::ConjugateGradientMinimizer::y_t_
protected

Variable needed for the Shanno direction calculation

Definition at line 228 of file conjugateGradient.h.