Stochastic Average Gradient Method for training of linear models,. More...

#include <shark/Algorithms/Trainers/LinearSAGTrainer.h>

Inheritance diagram for shark::LinearSAGTrainer< InputType, LabelType >:

Public Types
typedef Base::ModelType	ModelType

typedef Base::WeightedDatasetType	WeightedDatasetType

typedef detail::LinearSAGTrainerBase< InputType, LabelType >::LossType	LossType

Public Types inherited from shark::AbstractWeightedTrainer< Model, LabelTypeT >
typedef base_type::ModelType	ModelType

typedef base_type::InputType	InputType

typedef base_type::LabelType	LabelType

typedef base_type::DatasetType	DatasetType

typedef WeightedLabeledData< InputType, LabelType >	WeightedDatasetType

Public Types inherited from shark::AbstractTrainer< Model, LabelTypeT >
typedef Model	ModelType

typedef ModelType::InputType	InputType

typedef LabelTypeT	LabelType

typedef LabeledData< InputType, LabelType >	DatasetType

Public Types inherited from shark::IParameterizable<>
typedef RealVector	ParameterVectorType

Public Member Functions
	LinearSAGTrainer (LossType const *loss, double lambda=0, bool offset=true)
	Constructor. More...

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

void	train (ModelType &model, WeightedDatasetType const &dataset)
	Executes the algorithm and trains a model on the given weighted data. More...

std::size_t	epochs () const

void	setEpochs (std::size_t value)
	Set the number of training epochs. A value of 0 indicates that the default of max(10, dimensionOfData) should be used. More...

double	lambda () const
	Return the value of the regularization parameter lambda. More...

void	setLambda (double lambda)
	Set the value of the regularization parameter lambda. More...

bool	trainOffset () const
	Check whether the model to be trained should include an offset term. More...

void	setTrainOffset (bool offset)
	Sets whether the model to be trained should include an offset term. More...

RealVector	parameterVector () const
	Returns the vector of hyper-parameters(same as lambda) More...

void	setParameterVector (RealVector const &newParameters)
	Sets the vector of hyper-parameters(same as lambda) More...

size_t	numberOfParameters () const
	Returns the number of hyper-parameters. More...

Public Member Functions inherited from shark::AbstractWeightedTrainer< Model, LabelTypeT >
virtual void	train (ModelType &model, DatasetType const &dataset)
	Executes the algorithm and trains a model on the given unweighted data. More...

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

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

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 ()

Public Member Functions inherited from shark::IParameterizable<>
virtual	~IParameterizable ()

Detailed Description

template<class InputType, class LabelType>
class shark::LinearSAGTrainer< InputType, LabelType >

Stochastic Average Gradient Method for training of linear models,.

Given a differentiable loss function L(f, y) and a model f_j(x)= w_j^Tx+b this trainer solves the regularized risk minimization problem

\[ \min \frac{1}{2} \sum_j \frac{\lambda}{2}\|w_j\|^2 + \frac 1 {\ell} \sum_i L(y_i, f(x_i)), \]

where i runs over training data, j over the model outputs, and lambda > 0 is the regularization parameter.

The algorithm uses averaging of the algorithm to obtain a good estimate of the gradient. Averaging is performed by summing over the last gradient value obtained for each data point. At the beginning this estimate is far off as old gradient values are outdated, but as the algorithm converges, this gives linear convergence on strictly convex functions and O(1/T) convergence on not-strictly convex functions.

The algorithm supports classification and regresseion, dense and sparse inputs and weighted and unweighted datasets Reference: Schmidt, Mark, Nicolas Le Roux, and Francis Bach. "Minimizing finite sums with the stochastic average gradient." arXiv preprint arXiv:1309.2388 (2013).

Definition at line 90 of file LinearSAGTrainer.h.

Member Typedef Documentation

◆ LossType

template<class InputType, class LabelType>

typedef detail::LinearSAGTrainerBase<InputType,LabelType>::LossType shark::LinearSAGTrainer< InputType, LabelType >::LossType

Definition at line 97 of file LinearSAGTrainer.h.

◆ ModelType

template<class InputType, class LabelType>

typedef Base::ModelType shark::LinearSAGTrainer< InputType, LabelType >::ModelType

Definition at line 95 of file LinearSAGTrainer.h.

◆ WeightedDatasetType

template<class InputType, class LabelType>

typedef Base::WeightedDatasetType shark::LinearSAGTrainer< InputType, LabelType >::WeightedDatasetType

Definition at line 96 of file LinearSAGTrainer.h.

Constructor & Destructor Documentation

◆ LinearSAGTrainer()

template<class InputType, class LabelType>

shark::LinearSAGTrainer< InputType, LabelType >::LinearSAGTrainer	(	LossType const *	loss,
		double	lambda = `0`,
		bool	offset = `true`
	)

inline

Constructor.

Parameters

loss	(sub-)differentiable loss function
lambda	regularization parameter fort wo-norm regularization, 0 by default
offset	whether to train with offset/bias parameter or not, default is true

Definition at line 105 of file LinearSAGTrainer.h.

Member Function Documentation

◆ epochs()

template<class InputType, class LabelType>

std::size_t shark::LinearSAGTrainer< InputType, LabelType >::epochs ( ) const

inline

the number of training epochs. A value of 0 indicates that the default of max(10, dimensionOfData) should be used.

Definition at line 124 of file LinearSAGTrainer.h.

◆ lambda()

template<class InputType, class LabelType>

double shark::LinearSAGTrainer< InputType, LabelType >::lambda ( ) const

inline

Return the value of the regularization parameter lambda.

Definition at line 134 of file LinearSAGTrainer.h.

◆ name()

template<class InputType, class LabelType>

std::string shark::LinearSAGTrainer< InputType, LabelType >::name ( ) const

inlinevirtual

From INameable: return the class name.

Reimplemented from shark::INameable.

Definition at line 113 of file LinearSAGTrainer.h.

◆ numberOfParameters()

template<class InputType, class LabelType>

size_t shark::LinearSAGTrainer< InputType, LabelType >::numberOfParameters ( ) const

inlinevirtual

Returns the number of hyper-parameters.

Reimplemented from shark::IParameterizable<>.

Definition at line 163 of file LinearSAGTrainer.h.

References shark::Classifier< LinearModel< VectorType > >::decisionFunction(), shark::inputDimension(), shark::LinearModel< InputType, ActivationFunction >::inputShape(), shark::labelDimension(), shark::numberOfClasses(), shark::LinearModel< InputType, ActivationFunction >::outputShape(), shark::LinearModel< InputType, ActivationFunction >::setStructure(), and shark::DataView< DatasetType >::size().

◆ parameterVector()

template<class InputType, class LabelType>

RealVector shark::LinearSAGTrainer< InputType, LabelType >::parameterVector ( ) const

inlinevirtual

Returns the vector of hyper-parameters(same as lambda)

Reimplemented from shark::IParameterizable<>.

Definition at line 150 of file LinearSAGTrainer.h.

◆ setEpochs()

template<class InputType, class LabelType>

void shark::LinearSAGTrainer< InputType, LabelType >::setEpochs ( std::size_t value )

inline

Set the number of training epochs. A value of 0 indicates that the default of max(10, dimensionOfData) should be used.

Definition at line 129 of file LinearSAGTrainer.h.

Referenced by run().

◆ setLambda()

template<class InputType, class LabelType>

void shark::LinearSAGTrainer< InputType, LabelType >::setLambda ( double lambda )

inline

Set the value of the regularization parameter lambda.

Definition at line 138 of file LinearSAGTrainer.h.

References lambda.

◆ setParameterVector()

template<class InputType, class LabelType>

void shark::LinearSAGTrainer< InputType, LabelType >::setParameterVector ( RealVector const & newParameters )

inlinevirtual

Sets the vector of hyper-parameters(same as lambda)

Reimplemented from shark::IParameterizable<>.

Definition at line 156 of file LinearSAGTrainer.h.

References SIZE_CHECK.

◆ setTrainOffset()

template<class InputType, class LabelType>

void shark::LinearSAGTrainer< InputType, LabelType >::setTrainOffset ( bool offset )

inline

Sets whether the model to be trained should include an offset term.

Definition at line 146 of file LinearSAGTrainer.h.

◆ train()

template<class InputType, class LabelType>

void shark::LinearSAGTrainer< InputType, LabelType >::train	(	ModelType &	model,
		WeightedDatasetType const &	dataset
	)

inlinevirtual

Executes the algorithm and trains a model on the given weighted data.

Implements shark::AbstractWeightedTrainer< Model, LabelTypeT >.

Definition at line 117 of file LinearSAGTrainer.h.

References shark::random::globalRng.

Referenced by run().

◆ trainOffset()

template<class InputType, class LabelType>

bool shark::LinearSAGTrainer< InputType, LabelType >::trainOffset ( ) const

inline

Check whether the model to be trained should include an offset term.

Definition at line 142 of file LinearSAGTrainer.h.

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

include/shark/Algorithms/Trainers/LinearSAGTrainer.h

Public Types

Public Member Functions

Detailed Description

template<class InputType, class LabelType> class shark::LinearSAGTrainer< InputType, LabelType >

Member Typedef Documentation

◆ LossType

◆ ModelType

◆ WeightedDatasetType

Constructor & Destructor Documentation

◆ LinearSAGTrainer()

Member Function Documentation

◆ epochs()

◆ lambda()

◆ name()

◆ numberOfParameters()

◆ parameterVector()

◆ setEpochs()

◆ setLambda()

◆ setParameterVector()

◆ setTrainOffset()

◆ train()

◆ trainOffset()

template<class InputType, class LabelType>
class shark::LinearSAGTrainer< InputType, LabelType >