Provides a GP-specific interface to the generic problem class. More...

#include <problem.h>

Classes
struct	default_symbols_t

Public Member Functions
unsigned	categories () const

unsigned	classes () const

bool	classification () const
	Just a shorthand for checking number of classes. More...

dataframe &	data (dataset_t=dataset_t::training)

const dataframe &	data (dataset_t=dataset_t::training) const

bool	is_valid () const override

bool	operator! () const

std::size_t	setup_symbols (const std::filesystem::path &, typing=typing::weak)
	Sets up the symbol set. More...

std::size_t	setup_symbols (typing=typing::weak)
	Sets up the symbol set. More...

void	setup_terminals (typing)
	Inserts variables and states for nominal attributes into the symbol_set. More...

	src_problem ()
	New empty instance of src_problem. More...

	src_problem (const std::filesystem::path &, const default_symbols_t &, typing=typing::weak)
	Initializes the problem with the default symbol set and data coming from a file. More...

	src_problem (const std::filesystem::path &, const std::filesystem::path &, typing=typing::weak)
	Initializes the problem with data / symbols coming from input files. More...

	src_problem (const std::filesystem::path &, typing=typing::weak)
	Initializes problem dataset with examples coming from a file. More...

	src_problem (std::istream &, typing=typing::weak)
	Initializes problem dataset with examples coming from a file. More...

unsigned	variables () const

Public Member Functions inherited from vita::problem
template<class S , class ... Args>
symbol *	insert (Args &&... args)
	Adds a symbol to the internal symbol set. More...

template<class S , class ... Args>
symbol *	insert (Args &&...)

virtual bool	is_valid () const

	problem ()
	A new problem. More...

Static Public Attributes
static const default_symbols_t	default_symbols = {}

Additional Inherited Members
Public Attributes inherited from vita::problem
environment	env

symbol_set	sset

Detailed Description

Provides a GP-specific interface to the generic problem class.

The class is a facade that provides a simpler interface to represent symbolic regression / classification tasks.

Examples: titanic01.cc.

Definition at line 43 of file gp/src/problem.h.

Constructor & Destructor Documentation

◆ src_problem() [1/5]

vita::src_problem::src_problem ( )

New empty instance of src_problem.

Warning

Users must initialize:

the training dataset;
the entire symbol set (functions and terminals) before starting the evolution.

Definition at line 79 of file gp/src/problem.cc.

◆ src_problem() [2/5]

vita::src_problem::src_problem	(	const std::filesystem::path &	ds,
		typing	t = `typing::weak`
	)

explicit

Initializes problem dataset with examples coming from a file.

Parameters

[in]	ds	name of the dataset file (CSV or XRFF format)
[in]	t	weak or strong typing

Warning

Users must specify, at least, the functions to be used;
terminals directly derived from the data (variables / labels) are automatically inserted;
any additional terminal (ephemeral random constant, problem specific constant...) can be manually inserted.

Definition at line 96 of file gp/src/problem.cc.

◆ src_problem() [3/5]

vita::src_problem::src_problem	(	std::istream &	ds,
		typing	t = `typing::weak`
	)

explicit

Initializes problem dataset with examples coming from a file.

Parameters

[in]	ds	dataset
[in]	t	weak or strong typing

Warning

Users must specify, at least, the functions to be used;
terminals directly derived from the data (variables / labels) are automatically inserted;
any additional terminal (ephemeral random constant, problem specific constants...) can be manually inserted.

Definition at line 123 of file gp/src/problem.cc.

◆ src_problem() [4/5]

vita::src_problem::src_problem	(	const std::filesystem::path &	ds,
		const default_symbols_t &	,
		typing	t = `typing::weak`
	)

Initializes the problem with the default symbol set and data coming from a file.

Parameters

[in]	ds	name of the dataset file
[in]	t	weak or strong typing

Mainly useful for simple problems (single category regression / classification) or for the initial approach.

Definition at line 146 of file gp/src/problem.cc.

◆ src_problem() [5/5]

vita::src_problem::src_problem	(	const std::filesystem::path &	ds,
		const std::filesystem::path &	symbols,
		typing	t = `typing::weak`
	)

Initializes the problem with data / symbols coming from input files.

Parameters

[in]	ds	name of the training dataset file
[in]	symbols	name of the file containing the symbols to be used.
[in]	t	weak or strong typing

Definition at line 159 of file gp/src/problem.cc.

Member Function Documentation

◆ categories()

unsigned vita::src_problem::categories ( ) const

Returns: number of categories of the problem (>= 1)

Definition at line 470 of file gp/src/problem.cc.

◆ classes()

unsigned vita::src_problem::classes ( ) const

Returns: number of classes of the problem (== 0 for a symbolic regression problem, > 1 for a classification problem)

Definition at line 479 of file gp/src/problem.cc.

◆ classification()

bool vita::src_problem::classification ( ) const

inline

Just a shorthand for checking number of classes.

Definition at line 70 of file gp/src/problem.h.

◆ data() [1/2]

dataframe & vita::src_problem::data ( dataset_t t = dataset_t::training )

Parameters

[in] t a dataset type

Returns: a reference to the specified dataset

Definition at line 497 of file gp/src/problem.cc.

◆ data() [2/2]

const dataframe & vita::src_problem::data ( dataset_t t = dataset_t::training ) const

Parameters

[in] t a dataset type

Returns: a const reference to the specified dataset

Definition at line 506 of file gp/src/problem.cc.

◆ is_valid()

bool vita::src_problem::is_valid ( ) const

overridevirtual

Returns: true if the object passes the internal consistency check

Reimplemented from vita::problem.

Definition at line 514 of file gp/src/problem.cc.

◆ operator!()

bool vita::src_problem::operator! ( ) const

Returns: false if the current problem isn't ready for a run

Definition at line 177 of file gp/src/problem.cc.

◆ setup_symbols() [1/2]

std::size_t vita::src_problem::setup_symbols	(	const std::filesystem::path &	file,
		typing	t = `typing::weak`
	)

Sets up the symbol set.

Parameters

[in] file name of the file containing the symbols

Returns: number of parsed symbols

If a file isn't specified, a predefined set is arranged (useful for simple problems: single category regression / classification).

Warning: Data should be loaded before symbols: without data we don't know, among other things, the features the dataset has.

Definition at line 274 of file gp/src/problem.cc.

◆ setup_symbols() [2/2]

std::size_t vita::src_problem::setup_symbols ( typing t = typing::weak )

Sets up the symbol set.

Parameters

[in] t weak or strong typing

Returns: number of parsed symbols

A predefined set is arranged (useful for simple problems: single category regression / classification).

Warning: Data should be loaded before symbols: without data we don't know, among other things, the features the dataset has.

Definition at line 256 of file gp/src/problem.cc.

◆ setup_terminals()

void vita::src_problem::setup_terminals ( typing t )

Inserts variables and states for nominal attributes into the symbol_set.

Parameters

[in] t weak or strong typing

Exceptions

`std::data_format` unsupported state domain

There is one variable for each feature.

The names used for variables, if not specified in the dataset, are in the form X1, ... Xn.

Definition at line 194 of file gp/src/problem.cc.

◆ variables()

unsigned vita::src_problem::variables ( ) const

Returns: dimension of the input vectors (i.e. the number of variable of the problem)

Definition at line 488 of file gp/src/problem.cc.

Member Data Documentation

◆ default_symbols

const src_problem::default_symbols_t vita::src_problem::default_symbols = {}

static

Definition at line 53 of file gp/src/problem.h.

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

Classes

Public Member Functions

Static Public Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ src_problem() [1/5]

◆ src_problem() [2/5]

◆ src_problem() [3/5]

◆ src_problem() [4/5]

◆ src_problem() [5/5]

Member Function Documentation

◆ categories()

◆ classes()

◆ classification()

◆ data() [1/2]

◆ data() [2/2]

◆ is_valid()

◆ operator!()

◆ setup_symbols() [1/2]

◆ setup_symbols() [2/2]

◆ setup_terminals()

◆ variables()

Member Data Documentation

◆ default_symbols