BALL::EnergyMinimizer Class Reference
[Energy Minimizer]

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

Inheritance diagram for BALL::EnergyMinimizer:
Inheritance graph
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List of all members.

Classes

struct  Default
struct  Option

Public Member Functions

bool operator== (const EnergyMinimizer &energy_minimizer)
Constructors and Destructors

 EnergyMinimizer ()
 EnergyMinimizer (ForceField &force_field)
 EnergyMinimizer (ForceField &force_field, const Options &options)
 EnergyMinimizer (const EnergyMinimizer &energy_minimizer)
virtual ~EnergyMinimizer ()
Assignments

const EnergyMinimizeroperator= (const EnergyMinimizer &energy_minimizer)
Debugging and Diagnostics

bool isValid () const
Setup methods

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 specificSetup ()
Accessors

virtual bool isConverged () const
virtual double findStep ()
virtual void updateDirection ()
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
virtual bool minimize (Size steps=0, bool resume=false)
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

Public Attributes

Public Attributes

Options options

Protected Attributes

Protected Attributes

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_

Detailed Description

EnergyMinimizer. Base class for all minimizer for geometry optimization.

Definition at line 29 of file energyMinimizer.h.


Constructor & Destructor Documentation

BALL::EnergyMinimizer::EnergyMinimizer (  ) 

Default constructor.

BALL::EnergyMinimizer::EnergyMinimizer ( ForceField force_field  ) 

Constructor.

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

Constructor.

BALL::EnergyMinimizer::EnergyMinimizer ( const EnergyMinimizer energy_minimizer  ) 

Copy constructor

virtual BALL::EnergyMinimizer::~EnergyMinimizer (  )  [virtual]

Destructor.


Member Function Documentation

void BALL::EnergyMinimizer::enableEnergyAbortCondition ( bool  state  ) 

Specify if the MDSimulation aborts if the Energy is greater than abort_energy_

bool BALL::EnergyMinimizer::energyAbortConditionEnabled (  )  const

Query if the MDSimulation aborts if the Energy is greater than abort_energy_.

virtual double BALL::EnergyMinimizer::findStep (  )  [virtual]

Calculate the next step. This method is implemented in each minimizer class and tries to determine the next step to be taken. It typically performs a line search. The value returned is usually the step length with respect to the current direction.

Returns:
-1 to indicate failure

Reimplemented in BALL::ConjugateGradientMinimizer, BALL::ShiftedLVMMMinimizer, BALL::SteepestDescentMinimizer, and BALL::StrangLBFGSMinimizer.

virtual void BALL::EnergyMinimizer::finishIteration (  )  [virtual]

Finishing step for this iteration. This method should be called at the end of the main iteration loop implemented in minimize . It takes over some administrative stuff:

This method should be overwritten only in rare cases. Even then, the programmer should make sure to call EnergyMinimizer::finishIteration or has to take care of the above items himself.

All derived classes should call this method at the end of the minimize main loop. Otherwise strange things might happen.

See also:
minimize
Gradient& BALL::EnergyMinimizer::getDirection (  ) 

Return a reference to the current search direction

double& BALL::EnergyMinimizer::getEnergy (  ) 

Return a reference to the current energy

double BALL::EnergyMinimizer::getEnergy (  )  const

Return the current energy

float BALL::EnergyMinimizer::getEnergyDifferenceBound (  )  const

Get the energy difference bound

Size BALL::EnergyMinimizer::getEnergyOutputFrequency (  )  const

Get the energy ouput frequency

float BALL::EnergyMinimizer::getEnergyToAbort (  )  const
Size BALL::EnergyMinimizer::getEnergyUpdateCounter (  )  const

Return the number of energy updates since the start of the minimization.

ForceField* BALL::EnergyMinimizer::getForceField (  ) 

Return the force field of the energy minimizer

Size BALL::EnergyMinimizer::getForceUpdateCounter (  )  const

Return the number of force updates since the start of the minimization.

Gradient& BALL::EnergyMinimizer::getGradient (  ) 

Return a reference to the current gradient

double& BALL::EnergyMinimizer::getInitialEnergy (  ) 

Return a mutable reference to the initial energy

double BALL::EnergyMinimizer::getInitialEnergy (  )  const

Return the initial energy

Gradient& BALL::EnergyMinimizer::getInitialGradient (  ) 

Return a reference to the initial gradient

float BALL::EnergyMinimizer::getMaxGradient (  )  const

Get the maximum RMS gradient (first convergence criterion). The gradient unit of the gradient is kJ/(mol ).

float BALL::EnergyMinimizer::getMaximumDisplacement (  )  const

Get the maximum displacement value

Size BALL::EnergyMinimizer::getMaxNumberOfIterations (  )  const

Get the maximum number of iterations

Size BALL::EnergyMinimizer::getMaxSameEnergy (  )  const

Get the maximum number of iterations allowed with equal energy (second convergence criterion)

Size BALL::EnergyMinimizer::getNumberOfIterations (  )  const

Return the number of iterations performed.

Size BALL::EnergyMinimizer::getSnapShotFrequency (  )  const

Get the snapshot output frequency

virtual bool BALL::EnergyMinimizer::isConverged (  )  const [virtual]

Implements the convergence criterion. If the convergence criterion is fulfilled, this method returns true. The convergence criterion is implemented as one of two conditions:

(1) {RMS gradient} is below max_rms_gradient_ (2) same_energy_counter_ is above max_same_energy_

If any of these conditions hold isConverged returns true. This method should be reimplemented in derived classes for a different convergence criterion.

bool BALL::EnergyMinimizer::isValid (  )  const

Is the energy minimizer valid : did the setup work?

virtual bool BALL::EnergyMinimizer::minimize ( Size  steps = 0,
bool  resume = false 
) [virtual]

Minimize the energy of the system bound to the force field. If a number of steps is given, the minimization is aborted after that number of steps, regardless of the number of steps given in the options (MAX_STEPS). Together with the resume option this feature is used to extract properties or visualize the results in the course of the minimization. If resume is set to true, the minimization continues with the former step width and settings.

Parameters:
steps maximum number of steps to be taken
resume true if the minimization is to be resumed with the previous settings
Returns:
bool - true if the minimization has converged

Reimplemented in BALL::ConjugateGradientMinimizer, BALL::ShiftedLVMMMinimizer, BALL::SteepestDescentMinimizer, and BALL::StrangLBFGSMinimizer.

const EnergyMinimizer& BALL::EnergyMinimizer::operator= ( const EnergyMinimizer energy_minimizer  ) 

Assignment operator

bool BALL::EnergyMinimizer::operator== ( const EnergyMinimizer energy_minimizer  ) 

Equality operator

virtual void BALL::EnergyMinimizer::printEnergy (  )  const [virtual]

Print the energy. This method is called by finishIteration after every energy_output_frequency_ steps. It prints the current RMS gradient and the current energy to Log .info().

See also:
setEnergyOutputFrequency
getEnergyOutputFrequency
void BALL::EnergyMinimizer::setEnergyDifferenceBound ( float  energy_difference_bound  ) 

Set the energy difference bound for convergence

void BALL::EnergyMinimizer::setEnergyOutputFrequency ( Size  energy_output_frequency  ) 

Set the energy output frequency

void BALL::EnergyMinimizer::setEnergyToAbort ( float  value  ) 

Set the value for the energy, that will result in aborting the minization, if it will be surpassed. Default value: 10^9.

void BALL::EnergyMinimizer::setMaxGradient ( float  max_gradient  ) 

Set the maximum RMS gradient (first convergence criterion). The gradient unit of the gradient is kJ/(mol ).

void BALL::EnergyMinimizer::setMaximumDisplacement ( float  maximum_displacement  ) 

Set the maximum displacement value. This is the maximum distance an atom may be moved by the minimizer in one iteration.

void BALL::EnergyMinimizer::setMaxNumberOfIterations ( Size  number_of_iterations  ) 

Set the maximum number of iterations

void BALL::EnergyMinimizer::setMaxSameEnergy ( Size  number  ) 

Set the maximum number of iterations allowed with equal energy (second convergence criterion)

void BALL::EnergyMinimizer::setNumberOfIterations ( Size  number_of_iterations  ) 

Set the number of iterations performed so far.

void BALL::EnergyMinimizer::setSnapShotFrequency ( Size  snapshot_frequency  ) 

Set the snapshot frequency

bool BALL::EnergyMinimizer::setup ( ForceField force_field,
const Options options 
)

Sets up the energy minimizer.

bool BALL::EnergyMinimizer::setup ( ForceField force_field,
SnapShotManager ssm,
const Options options 
)

Sets up the energy minimizer.

bool BALL::EnergyMinimizer::setup ( ForceField force_field,
SnapShotManager ssm 
)

Sets up the energy minimizer.

bool BALL::EnergyMinimizer::setup ( ForceField force_field  ) 

Sets up the energy minimizer.

virtual bool BALL::EnergyMinimizer::specificSetup (  )  [virtual]
void BALL::EnergyMinimizer::storeGradientEnergy (  ) 

Store the current energy and gradient. The current gradient and current energy is copied into initial energy and initial gradient. This is usually done at the start of an iteration.

virtual void BALL::EnergyMinimizer::takeSnapShot (  )  const [virtual]

Take a snapshot of the system. This method is called by finishIteration after every snapshot_frequency_ steps. It saves a SnapShot of the current atom coordinates to a SnapShotManager (if enabled).

See also:
setSnapShotFrequency
getSnapShotFrequency
virtual void BALL::EnergyMinimizer::updateDirection (  )  [virtual]

Update the search direction. This method is implemented by the derived classes to implement a method to determine a new search direction.

Reimplemented in BALL::ConjugateGradientMinimizer, BALL::ShiftedLVMMMinimizer, BALL::SteepestDescentMinimizer, and BALL::StrangLBFGSMinimizer.

virtual double BALL::EnergyMinimizer::updateEnergy (  )  [virtual]

Update energy. This method calls force_field_->updateEnergy() and stores the result in current_energy_.

virtual void BALL::EnergyMinimizer::updateForces (  )  [virtual]

Update forces and store them in current_grad_. This method calls force_field_->updateForces() and stores them in current_grad_ .

bool BALL::EnergyMinimizer::wasAborted (  )  const

Return true, if the minimization was aborted, e.g. because of strange energies or gradient.


Member Data Documentation

Definition at line 545 of file energyMinimizer.h.

Definition at line 548 of file energyMinimizer.h.

Definition at line 551 of file energyMinimizer.h.

The current energy.

Definition at line 457 of file energyMinimizer.h.

The current gradient.

Definition at line 449 of file energyMinimizer.h.

Numerical lower bound: we don't want to compute the reciprocal of a number which is lower than 'cutlo_'.

Definition at line 537 of file energyMinimizer.h.

The current search direction

Definition at line 469 of file energyMinimizer.h.

If the energy difference (before and after an iteration) is smaller than this bound, the minimization procedure stops.

Definition at line 504 of file energyMinimizer.h.

Frequency of energy output

Definition at line 495 of file energyMinimizer.h.

Internal counter: how often is an energy update done. Measure for the speed of minimization.

Definition at line 532 of file energyMinimizer.h.

The force field bound to the energy minimizer. Among other data the force field contains the molecular system whose energy will be minimized by the energy minimizer.

Definition at line 483 of file energyMinimizer.h.

Internal counter: how often is a force update done. Measure for the speed of minimization.

Definition at line 527 of file energyMinimizer.h.

The energy at the beginning of the current minimization step.

Definition at line 453 of file energyMinimizer.h.

The gradient at the beginning of the current minimization step.

Definition at line 445 of file energyMinimizer.h.

The maximum RMS gradient tolerated (first convergence criterion)

Definition at line 508 of file energyMinimizer.h.

The maximum number of iterations with same energy. When this number is reached, we assume the system to have converged (second convergence criterion)

Definition at line 514 of file energyMinimizer.h.

Maximum number of iterations

Definition at line 491 of file energyMinimizer.h.

The maximal shift of an atom per iteration step (in Angstrom).

Definition at line 522 of file energyMinimizer.h.

The current iteration number

Definition at line 487 of file energyMinimizer.h.

The energy from the last step

Definition at line 465 of file energyMinimizer.h.

The gradient from the last step

Definition at line 461 of file energyMinimizer.h.

Options

Definition at line 434 of file energyMinimizer.h.

A counter for the number of steps with a similar energy.

Definition at line 518 of file energyMinimizer.h.

Pointer to a SnapShotManager for storing snapshots of the system

Definition at line 477 of file energyMinimizer.h.

Frequency of atom coordinate ouput

Definition at line 499 of file energyMinimizer.h.

The last step size (in respect of the length of the computed direction vector), so the length of the last step was $step\cdot|direction|$.

Definition at line 542 of file energyMinimizer.h.

The boolean variable indicates if the setup of the energy minimizer was successful

Definition at line 473 of file energyMinimizer.h.

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