Adaptive Moment Estimation Algorithm (ADAM) More...

#include <shark/Algorithms/GradientDescent/Adam.h>

Inheritance diagram for shark::Adam:

Public Member Functions
	Adam ()

std::string	name () const
	From INameable: return the class name. More...

void	init (ObjectiveFunctionType const &objectiveFunction, SearchPointType const &startingPoint)
	initializes the optimizer using a predefined starting point More...

double	eta () const
	get learning rate eta More...

void	setEta (double eta)
	set learning rate eta More...

double	beta1 () const
	get gradient averaging parameter beta1 More...

void	setBeta1 (double beta1)
	set gradient averaging parameter beta1 More...

double	beta2 () const
	get gradient averaging parameter beta2 More...

void	setBeta2 (double beta2)
	set gradient averaging parameter beta2 More...

double	epsilon () const
	get minimum noise estimate epsilon More...

void	setEpsilon (double epsilon)
	set minimum noise estimate epsilon More...

void	step (ObjectiveFunctionType const &objectiveFunction)
	Performs a step of the optimization. More...

virtual void	read (InArchive &archive)
	Read the component from the supplied archive. More...

virtual void	write (OutArchive &archive) const
	Write the component to the supplied archive. More...

Public Member Functions inherited from shark::AbstractSingleObjectiveOptimizer< RealVector >
std::size_t	numInitPoints () const
	By default most single objective optimizers only require a single point. More...

virtual void	init (ObjectiveFunctionType const &function, std::vector< SearchPointType > const &initPoints)
	Initialize the optimizer for the supplied objective function using a set of initialisation points. More...

virtual const SolutionType &	solution () const
	returns the current solution of the optimizer More...

Public Member Functions inherited from shark::AbstractOptimizer< RealVector, double, SingleObjectiveResultSet< RealVector > >
const Features &	features () const

virtual void	updateFeatures ()

bool	requiresValue () const

bool	requiresFirstDerivative () const

bool	requiresSecondDerivative () const

bool	canSolveConstrained () const

bool	requiresClosestFeasible () const

virtual	~AbstractOptimizer ()

virtual void	init (ObjectiveFunctionType const &function)
	Initialize the optimizer for the supplied objective function. More...

Public Member Functions inherited from shark::INameable
virtual	~INameable ()

Public Member Functions inherited from shark::ISerializable
virtual	~ISerializable ()
	Virtual d'tor. More...

void	load (InArchive &archive, unsigned int version)
	Versioned loading of components, calls read(...). More...

void	save (OutArchive &archive, unsigned int version) const
	Versioned storing of components, calls write(...). More...

	BOOST_SERIALIZATION_SPLIT_MEMBER ()

Additional Inherited Members
Public Types inherited from shark::AbstractSingleObjectiveOptimizer< RealVector >
typedef base_type::SearchPointType	SearchPointType

typedef base_type::SolutionType	SolutionType

typedef base_type::ResultType	ResultType

typedef base_type::ObjectiveFunctionType	ObjectiveFunctionType

Public Types inherited from shark::AbstractOptimizer< RealVector, double, SingleObjectiveResultSet< RealVector > >
enum	Feature
	Models features that the optimizer requires from the objective function. More...

typedef RealVector	SearchPointType

typedef double	ResultType

typedef SingleObjectiveResultSet< RealVector >	SolutionType

typedef AbstractObjectiveFunction< RealVector, ResultType >	ObjectiveFunctionType

typedef TypedFlags< Feature >	Features

typedef TypedFeatureNotAvailableException< Feature >	FeatureNotAvailableException

Protected Member Functions inherited from shark::AbstractOptimizer< RealVector, double, SingleObjectiveResultSet< RealVector > >
void	checkFeatures (ObjectiveFunctionType const &objectiveFunction)
	Convenience function that checks whether the features of the supplied objective function match with the required features of the optimizer. More...

Protected Attributes inherited from shark::AbstractSingleObjectiveOptimizer< RealVector >
SolutionType	m_best
	Current solution of the optimizer. More...

Protected Attributes inherited from shark::AbstractOptimizer< RealVector, double, SingleObjectiveResultSet< RealVector > >
Features	m_features

Detailed Description

Adaptive Moment Estimation Algorithm (ADAM)

Performs SGD by using a long term average of the gradient as well as its second moment to adapt a step size for each coordinate.

Definition at line 45 of file Adam.h.

Constructor & Destructor Documentation

◆ Adam()

shark::Adam::Adam ( )

inline

Definition at line 48 of file Adam.h.

References shark::AbstractOptimizer< RealVector, double, SingleObjectiveResultSet< RealVector > >::m_features, and shark::AbstractOptimizer< RealVector, double, SingleObjectiveResultSet< RealVector > >::REQUIRES_FIRST_DERIVATIVE.

Member Function Documentation

◆ beta1()

double shark::Adam::beta1 ( ) const

inline

get gradient averaging parameter beta1

Definition at line 88 of file Adam.h.

Referenced by setBeta1().

◆ beta2()

double shark::Adam::beta2 ( ) const

inline

get gradient averaging parameter beta2

Definition at line 99 of file Adam.h.

Referenced by setBeta2().

◆ epsilon()

double shark::Adam::epsilon ( ) const

inline

get minimum noise estimate epsilon

Definition at line 110 of file Adam.h.

Referenced by setEpsilon().

◆ eta()

double shark::Adam::eta ( ) const

inline

get learning rate eta

Definition at line 77 of file Adam.h.

Referenced by setEta().

◆ init()

void shark::Adam::init	(	ObjectiveFunctionType const &	function,
		SearchPointType const &	startingPoint
	)

inlinevirtual

initializes the optimizer using a predefined starting point

Implements shark::AbstractSingleObjectiveOptimizer< RealVector >.

Definition at line 61 of file Adam.h.

References shark::AbstractOptimizer< RealVector, double, SingleObjectiveResultSet< RealVector > >::checkFeatures(), shark::AbstractObjectiveFunction< PointType, ResultT >::numberOfVariables(), and SHARK_RUNTIME_CHECK.

Referenced by main().

◆ name()

std::string shark::Adam::name ( ) const

inlinevirtual

From INameable: return the class name.

Reimplemented from shark::INameable.

Definition at line 58 of file Adam.h.

◆ read()

virtual void shark::Adam::read ( InArchive & archive )

inlinevirtual

Read the component from the supplied archive.

Parameters

[in,out] archive The archive to read from.

Reimplemented from shark::ISerializable.

Definition at line 142 of file Adam.h.

References shark::AbstractSingleObjectiveOptimizer< RealVector >::m_best.

◆ setBeta1()

void shark::Adam::setBeta1 ( double beta1 )

inline

set gradient averaging parameter beta1

Definition at line 93 of file Adam.h.

References beta1(), and SHARK_RUNTIME_CHECK.

◆ setBeta2()

void shark::Adam::setBeta2 ( double beta2 )

inline

set gradient averaging parameter beta2

Definition at line 104 of file Adam.h.

References beta2(), and SHARK_RUNTIME_CHECK.

◆ setEpsilon()

void shark::Adam::setEpsilon ( double epsilon )

inline

set minimum noise estimate epsilon

Definition at line 115 of file Adam.h.

References epsilon(), and SHARK_RUNTIME_CHECK.

◆ setEta()

void shark::Adam::setEta ( double eta )

inline

set learning rate eta

Definition at line 82 of file Adam.h.

References eta(), and SHARK_RUNTIME_CHECK.

◆ step()

void shark::Adam::step ( ObjectiveFunctionType const & objectiveFunction )

inlinevirtual

Performs a step of the optimization.

First the current guess for gradient and its second moment are updated using

\[ g_t = \beta_1 g_{t-1} + (1-\beta1) \frac{\partial}{\partial x} f(x_{t-1})\]

\[ v_t = \beta_2 v_{t-1} + (1-\beta2) (\frac{\partial}{\partial x} f(x_{t-1}))^2\]

The step is then performed as

\[ x_{t} = x_{t-1} - \eta * g_t *(sqrt(v_t) + \epsilon)^{-1} \]

where a slight step correction is used to remove the bias in the first few iterations where the means are close to 0.

Implements shark::AbstractOptimizer< RealVector, double, SingleObjectiveResultSet< RealVector > >.

Definition at line 128 of file Adam.h.

Referenced by main().

◆ write()

virtual void shark::Adam::write ( OutArchive & archive ) const

inlinevirtual

Write the component to the supplied archive.

Parameters

[in,out] archive The archive to write to.

Reimplemented from shark::ISerializable.

Definition at line 156 of file Adam.h.

References shark::AbstractSingleObjectiveOptimizer< RealVector >::m_best.

The documentation for this class was generated from the following file:

include/shark/Algorithms/GradientDescent/Adam.h

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Adam()

Member Function Documentation

◆ beta1()

◆ beta2()

◆ epsilon()

◆ eta()

◆ init()

◆ name()

◆ read()

◆ setBeta1()

◆ setBeta2()

◆ setEpsilon()

◆ setEta()

◆ step()

◆ write()