This class contains methods which are used to calculate the cost of SVD++'s objective function, to calculate gradient of parameters with respect to the objective function, etc. More...

Public Member Functions
	SVDPlusPlusFunction (const MatType &data, const arma::sp_mat &implicitData, const size_t rank, const double lambda)
	Constructor for SVDPlusPlusFunction class. More...

const arma::mat &	Dataset () const
	Return the dataset passed into the constructor. More...

double	Evaluate (const arma::mat &parameters) const
	Evaluates the cost function over all examples in the data. More...

double	Evaluate (const arma::mat &parameters, const size_t start, const size_t batchSize=1) const
	Evaluates the cost function for one training example. More...

const arma::mat &	GetInitialPoint () const
	Return the initial point for the optimization. More...

void	Gradient (const arma::mat &parameters, arma::mat &gradient) const
	Evaluates the full gradient of the cost function over all the training examples. More...

template < typename GradType >
void	Gradient (const arma::mat &parameters, const size_t start, GradType &gradient, const size_t batchSize=1) const
	Evaluates the gradient of the cost function over one training example. More...

const arma::sp_mat &	ImplicitDataset () const
	Return the implicit data passed into the constructor. More...

double	Lambda () const
	Return the regularization parameters. More...

size_t	NumFunctions () const
	Return the number of training examples. Useful for SGD optimizer. More...

size_t	NumItems () const
	Return the number of items in the data. More...

size_t	NumUsers () const
	Return the number of users in the data. More...

size_t	Rank () const
	Return the rank used for the factorization. More...

void	Shuffle ()
	Shuffle the points in the dataset. More...

Detailed Description

template
<
typename
MatType
=
arma::mat
>

class mlpack::svd::SVDPlusPlusFunction< MatType >

This class contains methods which are used to calculate the cost of SVD++'s objective function, to calculate gradient of parameters with respect to the objective function, etc.

Template Parameters

MatType The matrix type of the dataset.

Definition at line 31 of file svdplusplus_function.hpp.

Constructor & Destructor Documentation

◆ SVDPlusPlusFunction()

SVDPlusPlusFunction	(	const MatType &	data,
		const arma::sp_mat &	implicitData,
		const size_t	rank,
		const double	lambda
	)

Constructor for SVDPlusPlusFunction class.

The constructor calculates the number of users and items in the passed data. It also randomly initializes the parameter values.

Parameters

data	Dataset for which SVD is calculated.
implicitData	Implicit feedback matrix where a non-zero entry means interaction between a user and an item is observed.
rank	Rank used for matrix factorization.
lambda	Regularization parameter used for optimization.

Member Function Documentation

◆ Dataset()

const arma::mat& Dataset ( ) const

inline

Return the dataset passed into the constructor.

Definition at line 110 of file svdplusplus_function.hpp.

◆ Evaluate() [1/2]

double Evaluate ( const arma::mat & parameters ) const

Evaluates the cost function over all examples in the data.

Parameters

parameters Parameters(user/item matrices, user/item bias, item implicit matrix) of the decomposition.

◆ Evaluate() [2/2]

double Evaluate	(	const arma::mat &	parameters,
		const size_t	start,
		const size_t	batchSize = `1`
	)		const

Evaluates the cost function for one training example.

Useful for the SGD optimizer abstraction which uses one training example at a time.

Parameters

parameters	Parameters(user/item matrices, user/item bias, item implicit matrix) of the decomposition.
start	First index of the training examples to be used.
batchSize	Size of batch to evaluate.

◆ GetInitialPoint()

const arma::mat& GetInitialPoint ( ) const

inline

Return the initial point for the optimization.

Definition at line 107 of file svdplusplus_function.hpp.

◆ Gradient() [1/2]

void Gradient	(	const arma::mat &	parameters,
		arma::mat &	gradient
	)		const

Evaluates the full gradient of the cost function over all the training examples.

Parameters

parameters	Parameters(user/item matrices, user/item bias, item implicit matrix) of the decomposition.
gradient	Calculated gradient for the parameters.

◆ Gradient() [2/2]

void Gradient	(	const arma::mat &	parameters,
		const size_t	start,
		GradType &	gradient,
		const size_t	batchSize = `1`
	)		const

Evaluates the gradient of the cost function over one training example.

This function is useful for optimizers like SGD. The type of the gradient parameter is a template argument to allow the computation of a sparse gradient.

Template Parameters

GradType The type of the gradient out-param.

Parameters

parameters	Parameters(user/item matrices, user/item bias, item implicit matrix) of the decomposition.
start	The first index of the training examples to use.
gradient	Calculated gradient for the parameters.
batchSize	Size of batch to calculate gradient for.

◆ ImplicitDataset()

const arma::sp_mat& ImplicitDataset ( ) const

inline

Return the implicit data passed into the constructor.

Definition at line 113 of file svdplusplus_function.hpp.

◆ Lambda()

double Lambda ( ) const

inline

Return the regularization parameters.

Definition at line 125 of file svdplusplus_function.hpp.

◆ NumFunctions()

size_t NumFunctions ( ) const

inline

Return the number of training examples. Useful for SGD optimizer.

Definition at line 116 of file svdplusplus_function.hpp.

◆ NumItems()

size_t NumItems ( ) const

inline

Return the number of items in the data.

Definition at line 122 of file svdplusplus_function.hpp.

◆ NumUsers()

size_t NumUsers ( ) const

inline

Return the number of users in the data.

Definition at line 119 of file svdplusplus_function.hpp.

◆ Rank()

size_t Rank ( ) const

inline

Return the rank used for the factorization.

Definition at line 128 of file svdplusplus_function.hpp.

◆ Shuffle()

void Shuffle ( )

Shuffle the points in the dataset.

This may be used by optimizers.

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

/home/ryan/src/mlpack.org/_src/mlpack-git/src/mlpack/methods/svdplusplus/svdplusplus_function.hpp

Public Member Functions

Detailed Description

template<typenameMatType=arma::mat> class mlpack::svd::SVDPlusPlusFunction< MatType >

Constructor & Destructor Documentation

◆ SVDPlusPlusFunction()

Member Function Documentation

◆ Dataset()

◆ Evaluate() [1/2]

◆ Evaluate() [2/2]

◆ GetInitialPoint()

◆ Gradient() [1/2]

◆ Gradient() [2/2]

◆ ImplicitDataset()

◆ Lambda()

◆ NumFunctions()

◆ NumItems()

◆ NumUsers()

◆ Rank()

◆ Shuffle()

template
<
typename
MatType
=
arma::mat
>

class mlpack::svd::SVDPlusPlusFunction< MatType >