Auxiliary information for a dataset, including mappings to/from strings and the datatype of each dimension. More...

Public Member Functions
	DatasetMapper (const size_t dimensionality=0)
	Create the DatasetMapper object with the given dimensionality. More...

	DatasetMapper (PolicyType &policy, const size_t dimensionality=0)
	Create the DatasetMapper object with the given policy and dimensionality. More...

size_t	Dimensionality () const
	Get the dimensionality of the DatasetMapper object (that is, how many dimensions it has information for). More...

PolicyType::MappedType	MapString (const std::string &string, const size_t dimension)
	Given the string and the dimension to which it belongs, return its numeric mapping. More...

template<typename eT >
void	MapTokens (const std::vector< std::string > &tokens, size_t &row, arma::Mat< eT > &matrix)
	MapTokens turns vector of strings into numeric variables and puts them into a given matrix. More...

size_t	NumMappings (const size_t dimension) const
	Get the number of mappings for a particular dimension. More...

const PolicyType &	Policy () const
	Return the policy of the mapper. More...

PolicyType &	Policy ()
	Modify the policy of the mapper (be careful!). More...

void	Policy (PolicyType &&policy)
	Modify (Replace) the policy of the mapper with a new policy. More...

template<typename Archive >
void	Serialize (Archive &ar, const unsigned int)
	Serialize the dataset information. More...

Datatype	Type (const size_t dimension) const
	Return the type of a given dimension (numeric or categorical). More...

Datatype &	Type (const size_t dimension)
	Modify the type of a given dimension (be careful!). More...

const std::string &	UnmapString (const size_t value, const size_t dimension)
	Return the string that corresponds to a given value in a given dimension. More...

PolicyType::MappedType	UnmapValue (const std::string &string, const size_t dimension)
	Return the value that corresponds to a given string in a given dimension. More...

Private Types
using	BiMapType = boost::bimap< std::string, typename PolicyType::MappedType >

using	MapType = std::unordered_map< size_t, std::pair< BiMapType, size_t >>

Private Attributes
MapType	maps
	maps object stores string and numerical pairs. More...

PolicyType	policy
	policy object tells dataset mapper how the categorical values should be More...

std::vector< Datatype >	types
	Types of each dimension. More...

Detailed Description

template<typename PolicyType>
class mlpack::data::DatasetMapper< PolicyType >

Auxiliary information for a dataset, including mappings to/from strings and the datatype of each dimension.

DatasetMapper objects are optionally produced by data::Load(), and store the type of each dimension (Datatype::numeric or Datatype::categorical) as well as mappings from strings to unsigned integers and vice versa.

Template Parameters

PolicyType Mapping policy used to specify MapString();

Definition at line 36 of file dataset_mapper.hpp.

Member Typedef Documentation

template<typename PolicyType >

using mlpack::data::DatasetMapper< PolicyType >::BiMapType = boost::bimap<std::string, typename PolicyType::MappedType>

private

Definition at line 146 of file dataset_mapper.hpp.

template<typename PolicyType >

using mlpack::data::DatasetMapper< PolicyType >::MapType = std::unordered_map<size_t, std::pair<BiMapType, size_t>>

private

Definition at line 151 of file dataset_mapper.hpp.

Constructor & Destructor Documentation

template<typename PolicyType >

mlpack::data::DatasetMapper< PolicyType >::DatasetMapper ( const size_t dimensionality = 0 )

explicit

Create the DatasetMapper object with the given dimensionality.

Note that the dimensionality cannot be changed later; you will have to create a new DatasetMapper object.

template<typename PolicyType >

mlpack::data::DatasetMapper< PolicyType >::DatasetMapper	(	PolicyType &	policy,
		const size_t	dimensionality = `0`
	)

explicit

Create the DatasetMapper object with the given policy and dimensionality.

Note that the dimensionality cannot be changed later; you will have to create a new DatasetMapper object. Policy can be modified by the modifier.

Member Function Documentation

template<typename PolicyType >

size_t mlpack::data::DatasetMapper< PolicyType >::Dimensionality ( ) const

Get the dimensionality of the DatasetMapper object (that is, how many dimensions it has information for).

If this object was created by a call to mlpack::data::Load(), then the dimensionality will be the same as the number of rows (dimensions) in the dataset.

template<typename PolicyType >

PolicyType::MappedType mlpack::data::DatasetMapper< PolicyType >::MapString	(	const std::string &	string,
		const size_t	dimension
	)

Given the string and the dimension to which it belongs, return its numeric mapping.

If no mapping yet exists, the string is added to the list of mappings for the given dimension. The dimension parameter refers to the index of the dimension of the string (i.e. the row in the dataset).

Parameters

string	String to find/create mapping for.
dimension	Index of the dimension of the string.

template<typename PolicyType >

template<typename eT >

void mlpack::data::DatasetMapper< PolicyType >::MapTokens	(	const std::vector< std::string > &	tokens,
		size_t &	row,
		arma::Mat< eT > &	matrix
	)

MapTokens turns vector of strings into numeric variables and puts them into a given matrix.

It is uses mapping policy to store categorical values to maps. How it determines whether a value is categorical and how it stores the categorical value into map and replaces with the numerical value all depends on the mapping policy object's MapTokens() funciton.

Template Parameters

eT	Type of armadillo matrix.

Parameters

tokens	Vector of variables inside a dimension.
row	Position of the given tokens.
matrix	Matrix to save the data into.

template<typename PolicyType >

size_t mlpack::data::DatasetMapper< PolicyType >::NumMappings ( const size_t dimension ) const

Get the number of mappings for a particular dimension.

If the dimension is numeric, then this will return 0.

template<typename PolicyType >

const PolicyType& mlpack::data::DatasetMapper< PolicyType >::Policy ( ) const

Return the policy of the mapper.

Referenced by mlpack::data::DatasetMapper< PolicyType >::Serialize().

template<typename PolicyType >

PolicyType& mlpack::data::DatasetMapper< PolicyType >::Policy ( )

Modify the policy of the mapper (be careful!).

template<typename PolicyType >

void mlpack::data::DatasetMapper< PolicyType >::Policy ( PolicyType && policy )

Modify (Replace) the policy of the mapper with a new policy.

template<typename PolicyType >

template<typename Archive >

void mlpack::data::DatasetMapper< PolicyType >::Serialize	(	Archive &	ar,
		const unsigned	int
	)

inline

Serialize the dataset information.

Definition at line 126 of file dataset_mapper.hpp.

References mlpack::data::CreateNVP(), mlpack::data::DatasetMapper< PolicyType >::maps, mlpack::data::DatasetMapper< PolicyType >::Policy(), and mlpack::data::DatasetMapper< PolicyType >::types.

template<typename PolicyType >

Datatype mlpack::data::DatasetMapper< PolicyType >::Type ( const size_t dimension ) const

Return the type of a given dimension (numeric or categorical).

template<typename PolicyType >

Datatype& mlpack::data::DatasetMapper< PolicyType >::Type ( const size_t dimension )

Modify the type of a given dimension (be careful!).

template<typename PolicyType >

const std::string& mlpack::data::DatasetMapper< PolicyType >::UnmapString	(	const size_t	value,
		const size_t	dimension
	)

Return the string that corresponds to a given value in a given dimension.

If the string is not a valid mapping in the given dimension, a std::invalid_argument is thrown.

Parameters

value	Mapped value for string.
dimension	Dimension to unmap string from.

template<typename PolicyType >

PolicyType::MappedType mlpack::data::DatasetMapper< PolicyType >::UnmapValue	(	const std::string &	string,
		const size_t	dimension
	)

Return the value that corresponds to a given string in a given dimension.

If the value is not a valid mapping in the given dimension, a std::invalid_argument is thrown.

Parameters

string	Mapped string for value.
dimension	Dimension to unmap string from.

Member Data Documentation

template<typename PolicyType >

MapType mlpack::data::DatasetMapper< PolicyType >::maps

private

maps object stores string and numerical pairs.

Definition at line 154 of file dataset_mapper.hpp.

Referenced by mlpack::data::DatasetMapper< PolicyType >::Serialize().

template<typename PolicyType >

PolicyType mlpack::data::DatasetMapper< PolicyType >::policy

private

policy object tells dataset mapper how the categorical values should be

Definition at line 158 of file dataset_mapper.hpp.

template<typename PolicyType >

std::vector<Datatype> mlpack::data::DatasetMapper< PolicyType >::types

private

Types of each dimension.

Definition at line 143 of file dataset_mapper.hpp.

Referenced by mlpack::data::DatasetMapper< PolicyType >::Serialize().

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

src/mlpack/core/data/dataset_mapper.hpp

Public Member Functions

Private Types

Private Attributes

Detailed Description

template<typename PolicyType> class mlpack::data::DatasetMapper< PolicyType >

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<typename PolicyType>
class mlpack::data::DatasetMapper< PolicyType >