itk::LineSearchOptimizer Class Reference

#include <itkLineSearchOptimizer.h>

Detailed Description

A base class for LineSearch optimizers.

Scales are expected to be handled by the main optimizer.

Definition at line 37 of file itkLineSearchOptimizer.h.

Inheritance diagram for itk::LineSearchOptimizer:

Public Types
typedef SmartPointer< const Self >	ConstPointer
typedef Superclass::CostFunctionType	CostFunctionType
typedef Superclass::DerivativeType	DerivativeType
typedef Superclass::MeasureType	MeasureType
typedef Superclass::ParametersType	ParametersType
typedef SmartPointer< Self >	Pointer
typedef LineSearchOptimizer	Self
typedef SingleValuedNonLinearOptimizer	Superclass

Public Member Functions
virtual const char *	GetClassName () const
virtual void	GetCurrentDerivative (DerivativeType &derivative) const =0
virtual double	GetCurrentStepLength () const
virtual MeasureType	GetCurrentValue (void) const =0
virtual void	GetCurrentValueAndDerivative (MeasureType &value, DerivativeType &derivative) const =0
virtual double	GetInitialStepLengthEstimate () const
virtual const ParametersType &	GetLineSearchDirection ()
virtual double	GetMaximumStepLength () const
virtual double	GetMinimumStepLength () const
virtual void	SetInitialDerivative (const DerivativeType &)
virtual void	SetInitialStepLengthEstimate (double _arg)
virtual void	SetInitialValue (MeasureType)
virtual void	SetLineSearchDirection (const ParametersType &arg)
virtual void	SetMaximumStepLength (double _arg)
virtual void	SetMinimumStepLength (double _arg)

Protected Member Functions
double	DirectionalDerivative (const DerivativeType &derivative) const
	LineSearchOptimizer ()
void	PrintSelf (std::ostream &os, Indent indent) const
virtual void	SetCurrentStepLength (double step)
virtual	~LineSearchOptimizer ()

Protected Attributes
double	m_CurrentStepLength

Private Member Functions
	LineSearchOptimizer (const Self &)
void	operator= (const Self &)

Private Attributes
double	m_InitialStepLengthEstimate
ParametersType	m_LineSearchDirection
double	m_MaximumStepLength
double	m_MinimumStepLength

Member Typedef Documentation

ConstPointer

typedef SmartPointer< const Self > itk::LineSearchOptimizer::ConstPointer

Definition at line 44 of file itkLineSearchOptimizer.h.

CostFunctionType

typedef Superclass::CostFunctionType itk::LineSearchOptimizer::CostFunctionType

Definition at line 52 of file itkLineSearchOptimizer.h.

DerivativeType

typedef Superclass::DerivativeType itk::LineSearchOptimizer::DerivativeType

Definition at line 51 of file itkLineSearchOptimizer.h.

MeasureType

typedef Superclass::MeasureType itk::LineSearchOptimizer::MeasureType

Definition at line 47 of file itkLineSearchOptimizer.h.

ParametersType

typedef Superclass::ParametersType itk::LineSearchOptimizer::ParametersType

Definition at line 50 of file itkLineSearchOptimizer.h.

Pointer

typedef SmartPointer< Self > itk::LineSearchOptimizer::Pointer

Definition at line 43 of file itkLineSearchOptimizer.h.

Self

typedef LineSearchOptimizer itk::LineSearchOptimizer::Self

Definition at line 41 of file itkLineSearchOptimizer.h.

Superclass

typedef SingleValuedNonLinearOptimizer itk::LineSearchOptimizer::Superclass

Definition at line 42 of file itkLineSearchOptimizer.h.

Constructor & Destructor Documentation

LineSearchOptimizer() [1/2]

itk::LineSearchOptimizer::LineSearchOptimizer ( )

protected

~LineSearchOptimizer()

virtual itk::LineSearchOptimizer::~LineSearchOptimizer ( )

inlineprotectedvirtual

Definition at line 120 of file itkLineSearchOptimizer.h.

LineSearchOptimizer() [2/2]

itk::LineSearchOptimizer::LineSearchOptimizer ( const Self &  )

private

Member Function Documentation

DirectionalDerivative()

double itk::LineSearchOptimizer::DirectionalDerivative ( const DerivativeType &  derivative ) const

protected

Computes the inner product of the argument and the line search direction.

GetClassName()

virtual const char* itk::LineSearchOptimizer::GetClassName ( ) const

virtual

Reimplemented in itk::MoreThuenteLineSearchOptimizer.

GetCurrentDerivative()

virtual void itk::LineSearchOptimizer::GetCurrentDerivative ( DerivativeType &  derivative ) const

pure virtual

Implemented in itk::MoreThuenteLineSearchOptimizer.

GetCurrentStepLength()

virtual double itk::LineSearchOptimizer::GetCurrentStepLength ( ) const

virtual

StepLength is a a scalar, defined as: m_InitialPosition + StepLength * m_LineSearchDirection = m_CurrentPosition

GetCurrentValue()

virtual MeasureType itk::LineSearchOptimizer::GetCurrentValue ( void  ) const

pure virtual

Implemented in itk::MoreThuenteLineSearchOptimizer.

GetCurrentValueAndDerivative()

virtual void itk::LineSearchOptimizer::GetCurrentValueAndDerivative ( MeasureType &  value, DerivativeType &  derivative  ) const

pure virtual

These methods must be implemented by inheriting classes. It depends on the specific line search algorithm if it already computed the value/derivative at the current position (in this case it can just copy the cached data). If it did not compute the value/derivative, it should call the cost function and evaluate the value/derivative at the current position.

These methods allow the main optimization algorithm to reuse data that the LineSearch algorithm already computed.

Implemented in itk::MoreThuenteLineSearchOptimizer.

GetInitialStepLengthEstimate()

virtual double itk::LineSearchOptimizer::GetInitialStepLengthEstimate ( ) const

virtual

GetLineSearchDirection()

virtual const ParametersType& itk::LineSearchOptimizer::GetLineSearchDirection ( )

virtual

GetMaximumStepLength()

virtual double itk::LineSearchOptimizer::GetMaximumStepLength ( ) const

virtual

GetMinimumStepLength()

virtual double itk::LineSearchOptimizer::GetMinimumStepLength ( ) const

virtual

operator=()

void itk::LineSearchOptimizer::operator= ( const Self &  )

private

PrintSelf()

void itk::LineSearchOptimizer::PrintSelf ( std::ostream &  os, Indent  indent  ) const

protected

SetCurrentStepLength()

virtual void itk::LineSearchOptimizer::SetCurrentStepLength ( double  step )

protectedvirtual

Set the current step length AND the current position, where the current position is computed as: m_CurrentPosition = m_InitialPosition + StepLength * m_LineSearchDirection

SetInitialDerivative()

virtual void itk::LineSearchOptimizer::SetInitialDerivative ( const DerivativeType &  )

inlinevirtual

Inheriting classes may override these methods if they need value/derivative information of the cost function at the initial position.

NB: It is not guaranteed that these methods are called. If a main optimizer by chance has this information, it should call these methods, to avoid possible unnecessary computations.

Reimplemented in itk::MoreThuenteLineSearchOptimizer.

Definition at line 73 of file itkLineSearchOptimizer.h.

SetInitialStepLengthEstimate()

virtual void itk::LineSearchOptimizer::SetInitialStepLengthEstimate ( double  _arg )

virtual

SetInitialValue()

virtual void itk::LineSearchOptimizer::SetInitialValue ( MeasureType  )

inlinevirtual

Reimplemented in itk::MoreThuenteLineSearchOptimizer.

Definition at line 75 of file itkLineSearchOptimizer.h.

SetLineSearchDirection()

virtual void itk::LineSearchOptimizer::SetLineSearchDirection ( const ParametersType &  arg )

inlinevirtual

Set/Get the LineSearchDirection

Definition at line 55 of file itkLineSearchOptimizer.h.

SetMaximumStepLength()

virtual void itk::LineSearchOptimizer::SetMaximumStepLength ( double  _arg )

virtual

SetMinimumStepLength()

virtual void itk::LineSearchOptimizer::SetMinimumStepLength ( double  _arg )

virtual

Settings: the maximum/minimum step length and the initial estimate. NOTE: Not all line search methods are guaranteed to do something with this information. However, if a certain optimizer (using a line search optimizer) has any idea about the steplength it can call these methods, 'in the hope' that the line search optimizer does something sensible with it.

Field Documentation

m_CurrentStepLength

double itk::LineSearchOptimizer::m_CurrentStepLength

protected

Definition at line 123 of file itkLineSearchOptimizer.h.

m_InitialStepLengthEstimate

double itk::LineSearchOptimizer::m_InitialStepLengthEstimate

private

Definition at line 144 of file itkLineSearchOptimizer.h.

m_LineSearchDirection

ParametersType itk::LineSearchOptimizer::m_LineSearchDirection

private

Definition at line 140 of file itkLineSearchOptimizer.h.

m_MaximumStepLength

double itk::LineSearchOptimizer::m_MaximumStepLength

private

Definition at line 143 of file itkLineSearchOptimizer.h.

m_MinimumStepLength

double itk::LineSearchOptimizer::m_MinimumStepLength

private

Definition at line 142 of file itkLineSearchOptimizer.h.