Encapsulate all necessary data that is needed for training or predicting using an SVM. More...

#include <data_set.hpp>

Classes
class	label_mapper
	Implements all necessary functionality to map arbitrary labels to labels usable by the C-SVMs. More...

class	scaling
	Implements all necessary data and functions needed for scaling a plssvm::data_set to an user-defined range. More...

Public Types
using	real_type = T
	The type of the data points: either `float` or `double`.

using	label_type = U
	The type of the labels: any arithmetic type or `std::string`.

using	size_type = std::size_t
	An unsigned integer type.

Public Member Functions
	data_set (const std::string &filename)
	Read the data points from the file `filename`. Automatically determines the plssvm::file_format_type based on the file extension. More...

	data_set (const std::string &filename, file_format_type format)
	Read the data points from the file `filename` assuming that the file is given in the `plssvm::file_format_type`. More...

	data_set (const std::string &filename, scaling scale_parameter)
	Read the data points from the file `filename` and scale it using the provided `scale_parameter`. Automatically determines the plssvm::file_format_type based on the file extension. More...

	data_set (const std::string &filename, file_format_type format, scaling scale_parameter)
	Read the data points from the file `filename` assuming that the file is given in the plssvm::file_format_type `format` and scale it using the provided `scale_parameter`. More...

	data_set (std::vector< std::vector< real_type >> data_points)
	Create a new data set using the provided `data_points`. More...

	data_set (std::vector< std::vector< real_type >> data_points, std::vector< label_type > labels)
	Create a new data set using the provided `data_points` and `labels`. More...

	data_set (std::vector< std::vector< real_type >> data_points, scaling scale_parameter)
	Create a new data set using the the provided `data_points` and scale them using the provided `scale_parameter`. More...

	data_set (std::vector< std::vector< real_type >> data_points, std::vector< label_type > labels, scaling scale_parameter)
	Create a new data set using the the provided `data_points` and `labels` and scale the `data_points` using the provided `scale_parameter`. More...

void	save (const std::string &filename, file_format_type format) const
	Save the data points and potential labels of this data set to the file `filename` using the file `format` type. More...

void	save (const std::string &filename) const
	Save the data points and potential labels of this data set to the file `filename`. Automatically determines the plssvm::file_format_type based on the file extension. More...

const std::vector< std::vector< real_type > > &	data () const noexcept
	Return the data points in this data set. More...

bool	has_labels () const noexcept
	Returns whether this data set contains labels or not. More...

optional_ref< const std::vector< label_type > >	labels () const noexcept
	Returns an optional reference to the labels in this data set. More...

std::optional< std::vector< label_type > >	different_labels () const
	Returns an optional to the different labels in this data set. More...

size_type	num_data_points () const noexcept
	Returns the number of data points in this data set. More...

size_type	num_features () const noexcept
	Returns the number of features in this data set. More...

size_type	num_different_labels () const noexcept
	Returns the number of different labels in this data set. More...

bool	is_scaled () const noexcept
	Returns whether this data set has been scaled or not. More...

optional_ref< const scaling >	scaling_factors () const noexcept
	Returns the scaling factors as an optional reference used to scale the data points in this data set. More...

Private Member Functions
	data_set ()
	Default construct an empty data set.

void	create_mapping ()
	Create the mapping between the provided labels and the internally used mapped values, i.e., { -1, 1 }. More...

void	scale ()
	Scale the feature values of the data set to the provided range. More...

void	read_file (const std::string &filename, file_format_type format)
	Read the data points and potential labels from the file `filename` assuming the plssvm::file_format_type `format`. More...

Private Attributes
std::shared_ptr< std::vector< std::vector< real_type > > >	X_ptr_ { nullptr }
	A pointer to the two-dimensional data points.

std::shared_ptr< std::vector< label_type > >	labels_ptr_ { nullptr }
	A pointer to the original labels of this data set; may be `nullptr` if no labels have been provided.

std::shared_ptr< std::vector< real_type > >	y_ptr_ { nullptr }
	A pointer to the mapped values of the labels of this data set; may be `nullptr` if no labels have been provided.

size_type	num_data_points_ { 0 }
	The number of data points in this data set.

size_type	num_features_ { 0 }
	The number of features in this data set.

std::shared_ptr< const label_mapper >	mapping_ { nullptr }
	The mapping used to convert the original label to its mapped value and vice versa; may be `nullptr` if no labels have been provided.

std::shared_ptr< scaling >	scale_parameters_ { nullptr }
	The scaling parameters used to scale the data points in this data set; may be `nullptr` if no data point scaling was requested.

Friends
template<typename , typename >
class	model

class	csvm

Detailed Description

template<typename T, typename U = int>
class plssvm::data_set< T, U >

Encapsulate all necessary data that is needed for training or predicting using an SVM.

May or may not contain labels! Internally, saves all data using std::shared_ptr to make a plssvm::data_set relatively cheap to copy!

Template Parameters

T	the floating point type of the data (must either be `float` or `double`)
U	the label type of the data (must be an arithmetic type or `std::string`; default: `int`)

Examples: csvm_examples.cpp, data_set_examples.cpp, and model_examples.cpp.

Constructor & Destructor Documentation

◆ data_set() [1/8]

template<typename T , typename U >

plssvm::data_set< T, U >::data_set ( const std::string & filename )

explicit

Read the data points from the file filename. Automatically determines the plssvm::file_format_type based on the file extension.

If filename ends with .arff it uses the ARFF parser, otherwise the LIBSVM parser is used.

Parameters

[in] filename the file to read the data points from

Exceptions

plssvm::invalid_file_format_exception all exceptions thrown by plssvm::data_set::read_file

◆ data_set() [2/8]

template<typename T , typename U >

plssvm::data_set< T, U >::data_set	(	const std::string &	filename,
		file_format_type	format
	)

Read the data points from the file filename assuming that the file is given in the plssvm::file_format_type.

Parameters

[in]	filename	the file to read the data points from
[in]	format	the assumed file format used to parse the data points

Exceptions

plssvm::invalid_file_format_exception all exceptions thrown by plssvm::data_set::read_file

◆ data_set() [3/8]

template<typename T , typename U >

plssvm::data_set< T, U >::data_set	(	const std::string &	filename,
		scaling	scale_parameter
	)

Read the data points from the file filename and scale it using the provided scale_parameter. Automatically determines the plssvm::file_format_type based on the file extension.

If filename ends with .arff it uses the ARFF parser, otherwise the LIBSVM parser is used.

Parameters

[in]	filename	the file to read the data points from
[in]	scale_parameter	the parameters used to scale the data set feature values to a given range

Exceptions

plssvm::invalid_file_format_exception	all exceptions thrown by plssvm::data_set::read_file
plssvm::data_set_exception	all exceptions thrown by plssvm::data_set::scale

◆ data_set() [4/8]

template<typename T , typename U >

plssvm::data_set< T, U >::data_set	(	const std::string &	filename,
		file_format_type	format,
		scaling	scale_parameter
	)

Read the data points from the file filename assuming that the file is given in the plssvm::file_format_type format and scale it using the provided scale_parameter.

Parameters

[in]	filename	the file to read the data points from
[in]	format	the assumed file format used to parse the data points
[in]	scale_parameter	the parameters used to scale the data set feature values to a given range

Exceptions

plssvm::invalid_file_format_exception	all exceptions thrown by plssvm::data_set::read_file
plssvm::data_set_exception	all exceptions thrown by plssvm::data_set::scale

◆ data_set() [5/8]

template<typename T , typename U >

plssvm::data_set< T, U >::data_set ( std::vector< std::vector< real_type >> data_points )

explicit

Create a new data set using the provided data_points.

Since no labels are provided, this data set may not be used to a call to plssvm::csvm::fit!

Parameters

[in] data_points the data points used in this data set

Exceptions

plssvm::data_set_exception	if the `data_points` vector is empty
plssvm::data_set_exception	if the data points in `data_points` have mismatching number of features
plssvm::data_set_exception	if any `data_point` has no features

◆ data_set() [6/8]

template<typename T , typename U >

plssvm::data_set< T, U >::data_set	(	std::vector< std::vector< real_type >>	data_points,
		std::vector< label_type >	labels
	)

Create a new data set using the provided data_points and labels.

Parameters

[in]	data_points	the data points used in this data set
[in]	labels	the labels used in this data set

Exceptions

plssvm::data_set_exception	if the `data_points` vector is empty
plssvm::data_set_exception	if the data points in `data_points` have mismatching number of features
plssvm::data_set_exception	if any `data_point` has no features
plssvm::data_set_exception	if the number of data points in `data_points` and number of `labels` mismatch

◆ data_set() [7/8]

template<typename T , typename U >

plssvm::data_set< T, U >::data_set	(	std::vector< std::vector< real_type >>	data_points,
		scaling	scale_parameter
	)

Create a new data set using the the provided data_points and scale them using the provided scale_parameter.

Parameters

[in]	data_points	the data points used in this data set
[in]	scale_parameter	the parameters used to scale the data set feature values to a given range

Exceptions

plssvm::data_set_exception	if the `data_points` vector is empty
plssvm::data_set_exception	if the data points in `data_points` have mismatching number of features
plssvm::data_set_exception	if any `data_point` has no features
plssvm::data_set_exception	all exceptions thrown by plssvm::data_set::scale

◆ data_set() [8/8]

template<typename T , typename U >

plssvm::data_set< T, U >::data_set	(	std::vector< std::vector< real_type >>	data_points,
		std::vector< label_type >	labels,
		scaling	scale_parameter
	)

Create a new data set using the the provided data_points and labels and scale the data_points using the provided scale_parameter.

Parameters

[in]	data_points	the data points used in this data set
[in]	labels	the labels used in this data set
[in]	scale_parameter	the parameters used to scale the data set feature values to a given range

Exceptions

plssvm::data_set_exception	if the `data_points` vector is empty
plssvm::data_set_exception	if the data points in `data_points` have mismatching number of features
plssvm::data_set_exception	if any `data_point` has no features
plssvm::data_set_exception	if the number of data points in `data_points` and number of `labels` mismatch
plssvm::data_set_exception	all exceptions thrown by plssvm::data_set::scale

Member Function Documentation

◆ save() [1/2]

template<typename T , typename U >

void plssvm::data_set< T, U >::save	(	const std::string &	filename,
		file_format_type	format
	)		const

Save the data points and potential labels of this data set to the file filename using the file format type.

Parameters

[in]	filename	the file to save the data points and labels to
[in]	format	the file format

◆ save() [2/2]

template<typename T , typename U >

void plssvm::data_set< T, U >::save ( const std::string & filename ) const

Save the data points and potential labels of this data set to the file filename. Automatically determines the plssvm::file_format_type based on the file extension.

Parameters

[in] filename the file to save the data points and labels to

Exceptions

plssvm::data_set_exception if the file extension isn't one of libsvm or arff

◆ data()

template<typename T , typename U = int>

const std::vector<std::vector<real_type> >& plssvm::data_set< T, U >::data ( ) const

inlinenoexcept

Return the data points in this data set.

Returns: the data points ([[nodiscard]])

◆ has_labels()

template<typename T , typename U = int>

bool plssvm::data_set< T, U >::has_labels ( ) const

inlinenoexcept

Returns whether this data set contains labels or not.

Returns: true if this data set contains labels, false otherwise ([[nodiscard]])

Examples: data_set_examples.cpp.

◆ labels()

template<typename T , typename U >

auto plssvm::data_set< T, U >::labels

noexcept

Returns an optional reference to the labels in this data set.

If the labels are present, they can be retrieved as std::vector using: dataset.labels()->get().

Returns: if this data set contains labels, returns a reference to them, otherwise returns a std::nullopt ([[nodiscard]])

◆ different_labels()

template<typename T , typename U >

auto plssvm::data_set< T, U >::different_labels

Returns an optional to the different labels in this data set.

If the data set contains the labels std::vector<int>{ -1, 1, 1, -1, -1, 1 }, this function returns the labels { -1, 1 }.

Note: Must not return a optional reference, since it would bind to a temporary!

Returns: if this data set contains labels, returns a reference to all different labels, otherwise returns a std::nullopt ([[nodiscard]])

◆ num_data_points()

template<typename T , typename U = int>

size_type plssvm::data_set< T, U >::num_data_points ( ) const

inlinenoexcept

Returns the number of data points in this data set.

Returns: the number of data points ([[nodiscard]])

◆ num_features()

template<typename T , typename U = int>

size_type plssvm::data_set< T, U >::num_features ( ) const

inlinenoexcept

Returns the number of features in this data set.

Returns: the number of features ([[nodiscard]])

◆ num_different_labels()

template<typename T , typename U = int>

size_type plssvm::data_set< T, U >::num_different_labels ( ) const

inlinenoexcept

Returns the number of different labels in this data set.

If the data set contains the labels std::vector<int>{ -1, 1, 1, -1, -1, 1 }, this function returns 2. It is the same as: dataset.different_labels()->size()

Returns: the number of different labels ([[nodiscard]])

◆ is_scaled()

template<typename T , typename U = int>

bool plssvm::data_set< T, U >::is_scaled ( ) const

inlinenoexcept

Returns whether this data set has been scaled or not.

The used scaling factors can be retrieved using plssvm::data_set::scaling_factors().

Returns: true if this data set has been scaled, false otherwise ([[nodiscard]])

◆ scaling_factors()

template<typename T , typename U >

auto plssvm::data_set< T, U >::scaling_factors

noexcept

Returns the scaling factors as an optional reference used to scale the data points in this data set.

Can be used to scale another data set in the same way (e.g., a test data set). If the data set has been scaled, the scaling factors can be retrieved as using: dataset.scaling_factors()->get().

Returns: the scaling factors ([[nodiscard]])

Examples: data_set_examples.cpp.

◆ create_mapping()

template<typename T , typename U >

void plssvm::data_set< T, U >::create_mapping

private

Create the mapping between the provided labels and the internally used mapped values, i.e., { -1, 1 }.

Exceptions

plssvm::data_set_exception any exception of the plssvm::data_set::label_mapper class

◆ scale()

template<typename T , typename U >

void plssvm::data_set< T, U >::scale

private

Scale the feature values of the data set to the provided range.

Scales all data points feature wise, i.e., one scaling factor is responsible, e.g., for the first feature of all data points.
Scaling a data value \(x\) to the range \([a, b]\) is done with the formular: \(x_{scaled} = a + (b - a) \cdot \frac{x - min(x)}{max(x) - min(x)}\)

Exceptions

plssvm::data_set_exception	if more scaling factors than features are present
plssvm::data_set_exception	if the largest scaling factor index is larger than the number of features
plssvm::data_set_exception	if for any feature more than one scaling factor is present

◆ read_file()

template<typename T , typename U >

void plssvm::data_set< T, U >::read_file	(	const std::string &	filename,
		file_format_type	format
	)

private

Read the data points and potential labels from the file filename assuming the plssvm::file_format_type format.

Parameters

[in]	filename	the filename to read the data from
[in]	format	the assumed file format type

Exceptions

plssvm::invalid_file_format_exception	all exceptions thrown by the respective functions in the plssvm::detail::io namespace
plssvm::data_set_exception	if labels are present in `filename`, all exceptions thrown by plssvm::data_set::create_mapping

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

include/plssvm/data_set.hpp

Classes

Public Types

Public Member Functions

Private Member Functions

Private Attributes

Friends

Detailed Description

template<typename T, typename U = int> class plssvm::data_set< T, U >

Constructor & Destructor Documentation

◆ data_set() [1/8]

◆ data_set() [2/8]

◆ data_set() [3/8]

◆ data_set() [4/8]

◆ data_set() [5/8]

◆ data_set() [6/8]

◆ data_set() [7/8]

◆ data_set() [8/8]

Member Function Documentation

◆ save() [1/2]

◆ save() [2/2]

◆ data()

◆ has_labels()

◆ labels()

◆ different_labels()

◆ num_data_points()

◆ num_features()

◆ num_different_labels()

◆ is_scaled()

◆ scaling_factors()

◆ create_mapping()

◆ scale()

◆ read_file()

template<typename T, typename U = int>
class plssvm::data_set< T, U >