Class to perform optimization using firefly algorithm [32], [33]. More...

#include <num_collect/opt/firefly_optimizer.h>

Inheritance diagram for num_collect::opt::firefly_optimizer< ObjectiveFunction >:

Collaboration diagram for num_collect::opt::firefly_optimizer< ObjectiveFunction >:

Public Types
using	objective_function_type = ObjectiveFunction
	Type of the objective function.
using	random_number_generator_type = std::mt19937
	Type of the random number generator.
using	this_type = firefly_optimizer<ObjectiveFunction>
	This class.
using	value_type = typename objective_function_type::value_type
	Type of function values.
using	variable_scalar_type = typename variable_type::Scalar
	Type of scalars in variables.
using	variable_type = typename objective_function_type::variable_type
	Type of variables.

Public Member Functions
	firefly_optimizer (const ObjectiveFunction &obj_fun=ObjectiveFunction())
	Construct.
auto	absorption_coeff (variable_scalar_type value) -> this_type &
	Set the light absorption coefficient.
auto	attractiveness_coeff (variable_scalar_type value) -> this_type &
	Set the coefficient of the attractiveness.
void	change_objective_function (const objective_function_type &obj_fun)
	Change the objective function.
void	configure_iteration_logger (logging::iterations::iteration_logger< firefly_optimizer< ObjectiveFunction > > &iteration_logger) const
	Configure an iteration logger.
auto	evaluations () const noexcept -> index_type
	Get the number of function evaluations.
void	init (const variable_type &lower, const variable_type &upper)
	Initialize the algorithm.
auto	is_stop_criteria_satisfied () const -> bool
	Determine if stopping criteria of the algorithm are satisfied.
void	iterate ()
	Iterate the algorithm once.
auto	iterations () const noexcept -> index_type
	Get the number of iterations.
auto	max_evaluations (index_type value) -> this_type &
	Set the maximum number of function evaluations.
auto	num_fireflies (index_type value) -> this_type &
	Set the number of fireflies.
auto	opt_value () const -> const value_type &
	Get current optimal value.
auto	opt_variable () const -> const variable_type &
	Get current optimal variable.
auto	random_coeff (variable_scalar_type value) -> this_type &
	Set the coefficient of the random walk.
auto	seed (random_number_generator_type::result_type value) -> this_type &
	Change the seed of the random number generator.
Public Member Functions inherited from num_collect::opt::optimizer_base< firefly_optimizer< ObjectiveFunction > >
	optimizer_base (logging::log_tag_view tag)
	Constructor.
auto	evaluations () const noexcept -> index_type
	Get the number of function evaluations.
auto	iterations () const noexcept -> index_type
	Get the number of iterations.
auto	opt_value () const
	Get current optimal value.
auto	opt_variable () const
	Get current optimal variable.
Public Member Functions inherited from num_collect::base::iterative_solver_base< firefly_optimizer< ObjectiveFunction > >
	iterative_solver_base (logging::log_tag_view tag)
	Constructor.
auto	is_stop_criteria_satisfied () const -> bool
	Determine if stopping criteria of the algorithm are satisfied.
void	iterate ()
	Iterate the algorithm once.
void	solve ()
	Solve the problem.
Public Member Functions inherited from num_collect::logging::logging_mixin
	logging_mixin (log_tag_view tag)
	Constructor.
template<typename Child>
void	configure_child_algorithm_logger_if_exists (Child &child)
	Configure a logger of a child algorithm if exists.
auto	logger () const noexcept -> const num_collect::logging::logger &
	Access to the logger.
auto	logger () noexcept -> num_collect::logging::logger &
	Access to the logger.
Public Member Functions inherited from num_collect::logging::iterations::iteration_logger_mixin< firefly_optimizer< ObjectiveFunction > >
	iteration_logger_mixin ()=default
	Constructor.
void	configure_iteration_logger (num_collect::logging::iterations::iteration_logger< firefly_optimizer< ObjectiveFunction > > &iteration_logger) const
	Configure an iteration logger.
auto	initialize_iteration_logger () -> num_collect::logging::iterations::iteration_logger< firefly_optimizer< ObjectiveFunction > > &
	Get the iteration logger.

Private Member Functions
auto	evaluate_on (const variable_type &variable) -> value_type
	Evaluate a function value.

Static Private Member Functions
static auto	correct_value_if_needed (value_type value) noexcept -> value_type
	Correct function values if needed.

Private Attributes
variable_scalar_type	absorption_coeff_ {default_absorption_coeff}
	Light absorption coefficient.
variable_scalar_type	attractiveness_coeff_ {default_attractiveness_coeff}
	Coefficient of the attractiveness.
index_type	dim_ {0}
	Number of dimension.
index_type	evaluations_ {0}
	Number of function evaluations.
std::uniform_real_distribution< variable_scalar_type >	initial_distribution_ {}
	Distribution for the initial variables. (Uniform distribution from 0 to 1.)
index_type	iterations_ {0}
	Number of iterations.
variable_type	lower_ {}
	Element-wise lower limit.
index_type	max_evaluations_ {default_max_evaluations}
	Maximum number of function evaluations.
index_type	num_fireflies_ {default_num_fireflies}
	Number of fireflies.
objective_function_type	obj_fun_
	Objective function.
value_type	opt_value_ {std::numeric_limits<value_type>::max()}
	Current optimal value.
variable_type	opt_variable_ {}
	Current optimal variable.
variable_scalar_type	random_coeff_ {default_random_coeff}
	Coefficient of the random walk.
random_number_generator_type	random_number_generator_
	Random number generator.
std::normal_distribution< variable_scalar_type >	random_walk_distribution_ {}
	Distribution for random walk. (Standard normal distribution.)
variable_type	upper_ {}
	Element-wise upper limit.
Eigen::VectorX< value_type >	values_
	Function values of the current variables.
util::vector< variable_type >	variable_changes_
	Buffer of variable changes.
util::vector< variable_type >	variables_
	Current variables. (Positions of fireflies.)
variable_type	width_ {}
	Element-wise width.

Static Private Attributes
static constexpr auto	default_absorption_coeff
	Default value of the light absorption coefficient.
static constexpr auto	default_attractiveness_coeff
	Default value of the coefficient of the attractiveness.
static constexpr index_type	default_max_evaluations = 10000
	Default maximum number of function evaluations.
static constexpr index_type	default_num_fireflies = 200
	Default value of the number of fireflies.
static constexpr auto	default_random_coeff
	Default value of the coefficient of the random walk.

Additional Inherited Members
Protected Member Functions inherited from num_collect::base::iterative_solver_base< firefly_optimizer< ObjectiveFunction > >
auto	derived () noexcept -> firefly_optimizer< ObjectiveFunction > &
	Access derived object.

Detailed Description

template<concepts::multi_variate_objective_function ObjectiveFunction>
class num_collect::opt::firefly_optimizer< ObjectiveFunction >

Class to perform optimization using firefly algorithm [32], [33].

Template Parameters

ObjectiveFunction Type of the objective function.

Definition at line 63 of file firefly_optimizer.h.

Member Typedef Documentation

◆ objective_function_type

template<concepts::multi_variate_objective_function ObjectiveFunction>

using num_collect::opt::firefly_optimizer< ObjectiveFunction >::objective_function_type = ObjectiveFunction

Type of the objective function.

Definition at line 70 of file firefly_optimizer.h.

◆ random_number_generator_type

template<concepts::multi_variate_objective_function ObjectiveFunction>

using num_collect::opt::firefly_optimizer< ObjectiveFunction >::random_number_generator_type = std::mt19937

Type of the random number generator.

Definition at line 82 of file firefly_optimizer.h.

◆ this_type

template<concepts::multi_variate_objective_function ObjectiveFunction>

using num_collect::opt::firefly_optimizer< ObjectiveFunction >::this_type = firefly_optimizer<ObjectiveFunction>

This class.

Definition at line 67 of file firefly_optimizer.h.

◆ value_type

template<concepts::multi_variate_objective_function ObjectiveFunction>

using num_collect::opt::firefly_optimizer< ObjectiveFunction >::value_type = typename objective_function_type::value_type

Type of function values.

Definition at line 79 of file firefly_optimizer.h.

◆ variable_scalar_type

template<concepts::multi_variate_objective_function ObjectiveFunction>

using num_collect::opt::firefly_optimizer< ObjectiveFunction >::variable_scalar_type = typename variable_type::Scalar

Type of scalars in variables.

Definition at line 76 of file firefly_optimizer.h.

◆ variable_type

template<concepts::multi_variate_objective_function ObjectiveFunction>

using num_collect::opt::firefly_optimizer< ObjectiveFunction >::variable_type = typename objective_function_type::variable_type

Type of variables.

Definition at line 73 of file firefly_optimizer.h.

Constructor & Destructor Documentation

◆ firefly_optimizer()

template<concepts::multi_variate_objective_function ObjectiveFunction>

num_collect::opt::firefly_optimizer< ObjectiveFunction >::firefly_optimizer ( const ObjectiveFunction & obj_fun = ObjectiveFunction() )

inlineexplicit

Construct.

Parameters

[in] obj_fun Objective function.

Definition at line 89 of file firefly_optimizer.h.

Member Function Documentation

◆ absorption_coeff()

template<concepts::multi_variate_objective_function ObjectiveFunction>

auto num_collect::opt::firefly_optimizer< ObjectiveFunction >::absorption_coeff ( variable_scalar_type value ) -> this_type&

inline

Set the light absorption coefficient.

Note: This value is \(\gamma\) in [32].

Parameters

[in] value Value.

Returns: This object.

Definition at line 286 of file firefly_optimizer.h.

◆ attractiveness_coeff()

template<concepts::multi_variate_objective_function ObjectiveFunction>

auto num_collect::opt::firefly_optimizer< ObjectiveFunction >::attractiveness_coeff ( variable_scalar_type value ) -> this_type&

inline

Set the coefficient of the attractiveness.

Note: This value is \(\beta 0\) in [32].

Parameters

[in] value Value.

Returns: This object.

Definition at line 271 of file firefly_optimizer.h.

◆ change_objective_function()

template<concepts::multi_variate_objective_function ObjectiveFunction>

void num_collect::opt::firefly_optimizer< ObjectiveFunction >::change_objective_function ( const objective_function_type & obj_fun )

inline

Change the objective function.

Parameters

[in] obj_fun Objective function.

Definition at line 98 of file firefly_optimizer.h.

◆ configure_iteration_logger()

template<concepts::multi_variate_objective_function ObjectiveFunction>

void num_collect::opt::firefly_optimizer< ObjectiveFunction >::configure_iteration_logger ( logging::iterations::iteration_logger< firefly_optimizer< ObjectiveFunction > > & iteration_logger ) const

inline

Configure an iteration logger.

Parameters

[in] iteration_logger Iteration logger.

Definition at line 212 of file firefly_optimizer.h.

◆ correct_value_if_needed()

template<concepts::multi_variate_objective_function ObjectiveFunction>

auto num_collect::opt::firefly_optimizer< ObjectiveFunction >::correct_value_if_needed ( value_type value ) -> value_type

inlinestaticnodiscardprivatenoexcept

Correct function values if needed.

Parameters

[in] value Function value.

Returns: Corrected value.

Definition at line 358 of file firefly_optimizer.h.

◆ evaluate_on()

template<concepts::multi_variate_objective_function ObjectiveFunction>

auto num_collect::opt::firefly_optimizer< ObjectiveFunction >::evaluate_on ( const variable_type & variable ) -> value_type

inlinenodiscardprivate

Evaluate a function value.

Parameters

[in] variable Variable.

Returns: Function value.

Definition at line 340 of file firefly_optimizer.h.

◆ evaluations()

template<concepts::multi_variate_objective_function ObjectiveFunction>

auto num_collect::opt::firefly_optimizer< ObjectiveFunction >::evaluations ( ) const -> index_type

inlinenodiscardnoexcept

Get the number of function evaluations.

Returns: Number of function evaluations.

Definition at line 246 of file firefly_optimizer.h.

◆ init()

template<concepts::multi_variate_objective_function ObjectiveFunction>

void num_collect::opt::firefly_optimizer< ObjectiveFunction >::init	(	const variable_type &	lower,
		const variable_type &	upper )

inline

Initialize the algorithm.

Parameters

[in]	lower	Lower limit.
[in]	upper	Upper limit.

Definition at line 108 of file firefly_optimizer.h.

◆ is_stop_criteria_satisfied()

template<concepts::multi_variate_objective_function ObjectiveFunction>

auto num_collect::opt::firefly_optimizer< ObjectiveFunction >::is_stop_criteria_satisfied ( ) const -> bool

inlinenodiscard

Determine if stopping criteria of the algorithm are satisfied.

Returns: If stopping criteria of the algorithm are satisfied.

Definition at line 205 of file firefly_optimizer.h.

◆ iterate()

template<concepts::multi_variate_objective_function ObjectiveFunction>

void num_collect::opt::firefly_optimizer< ObjectiveFunction >::iterate ( )

inline

Iterate the algorithm once.

Warning: Any required initializations (with init functions) are assumed to have been done.

Definition at line 143 of file firefly_optimizer.h.

◆ iterations()

template<concepts::multi_variate_objective_function ObjectiveFunction>

auto num_collect::opt::firefly_optimizer< ObjectiveFunction >::iterations ( ) const -> index_type

inlinenodiscardnoexcept

Get the number of iterations.

Returns: Number of iterations.

Definition at line 239 of file firefly_optimizer.h.

◆ max_evaluations()

template<concepts::multi_variate_objective_function ObjectiveFunction>

auto num_collect::opt::firefly_optimizer< ObjectiveFunction >::max_evaluations ( index_type value ) -> this_type&

inline

Set the maximum number of function evaluations.

Parameters

[in] value Value.

Returns: This object.

Definition at line 314 of file firefly_optimizer.h.

◆ num_fireflies()

template<concepts::multi_variate_objective_function ObjectiveFunction>

auto num_collect::opt::firefly_optimizer< ObjectiveFunction >::num_fireflies ( index_type value ) -> this_type&

inline

Set the number of fireflies.

Parameters

[in] value Value.

Returns: This object.

Definition at line 256 of file firefly_optimizer.h.

◆ opt_value()

template<concepts::multi_variate_objective_function ObjectiveFunction>

auto num_collect::opt::firefly_optimizer< ObjectiveFunction >::opt_value ( ) const -> const value_type&

inlinenodiscard

Get current optimal value.

Returns: Current optimal value.

Definition at line 232 of file firefly_optimizer.h.

◆ opt_variable()

template<concepts::multi_variate_objective_function ObjectiveFunction>

auto num_collect::opt::firefly_optimizer< ObjectiveFunction >::opt_variable ( ) const -> const variable_type&

inlinenodiscard

Get current optimal variable.

Returns: Current optimal variable.

Definition at line 225 of file firefly_optimizer.h.

◆ random_coeff()

template<concepts::multi_variate_objective_function ObjectiveFunction>

auto num_collect::opt::firefly_optimizer< ObjectiveFunction >::random_coeff ( variable_scalar_type value ) -> this_type&

inline

Set the coefficient of the random walk.

Note: This value is \(\alpha\) in [32].

Parameters

[in] value Value.

Returns: This object.

Definition at line 301 of file firefly_optimizer.h.

◆ seed()

template<concepts::multi_variate_objective_function ObjectiveFunction>

auto num_collect::opt::firefly_optimizer< ObjectiveFunction >::seed ( random_number_generator_type::result_type value ) -> this_type&

inline

Change the seed of the random number generator.

Parameters

[in] value Value.

Returns: This.

Definition at line 328 of file firefly_optimizer.h.

Member Data Documentation

◆ absorption_coeff_

template<concepts::multi_variate_objective_function ObjectiveFunction>

variable_scalar_type num_collect::opt::firefly_optimizer< ObjectiveFunction >::absorption_coeff_ {default_absorption_coeff}

private

Light absorption coefficient.

Note: This value is \(\gamma\) in [32].

Definition at line 408 of file firefly_optimizer.h.

◆ attractiveness_coeff_

template<concepts::multi_variate_objective_function ObjectiveFunction>

variable_scalar_type num_collect::opt::firefly_optimizer< ObjectiveFunction >::attractiveness_coeff_ {default_attractiveness_coeff}

private

Coefficient of the attractiveness.

Note: This value is \(\beta 0\) in [32].

Definition at line 397 of file firefly_optimizer.h.

◆ default_absorption_coeff

template<concepts::multi_variate_objective_function ObjectiveFunction>

auto num_collect::opt::firefly_optimizer< ObjectiveFunction >::default_absorption_coeff

staticconstexprprivate

Initial value:

=

static_cast<variable_scalar_type>(300)

num_collect::opt::firefly_optimizer< ObjectiveFunction >::variable_scalar_type

typename variable_type::Scalar variable_scalar_type

Type of scalars in variables.

Definition firefly_optimizer.h:76

Default value of the light absorption coefficient.

Definition at line 400 of file firefly_optimizer.h.

◆ default_attractiveness_coeff

template<concepts::multi_variate_objective_function ObjectiveFunction>

auto num_collect::opt::firefly_optimizer< ObjectiveFunction >::default_attractiveness_coeff

staticconstexprprivate

Initial value:

=

static_cast<variable_scalar_type>(1)

Default value of the coefficient of the attractiveness.

Definition at line 389 of file firefly_optimizer.h.

◆ default_max_evaluations

template<concepts::multi_variate_objective_function ObjectiveFunction>

index_type num_collect::opt::firefly_optimizer< ObjectiveFunction >::default_max_evaluations = 10000

staticconstexprprivate

Default maximum number of function evaluations.

Definition at line 454 of file firefly_optimizer.h.

◆ default_num_fireflies

template<concepts::multi_variate_objective_function ObjectiveFunction>

index_type num_collect::opt::firefly_optimizer< ObjectiveFunction >::default_num_fireflies = 200

staticconstexprprivate

Default value of the number of fireflies.

Definition at line 383 of file firefly_optimizer.h.

◆ default_random_coeff

template<concepts::multi_variate_objective_function ObjectiveFunction>

auto num_collect::opt::firefly_optimizer< ObjectiveFunction >::default_random_coeff

staticconstexprprivate

Initial value:

=

static_cast<variable_scalar_type>(0.1)

Default value of the coefficient of the random walk.

Definition at line 411 of file firefly_optimizer.h.

◆ dim_

template<concepts::multi_variate_objective_function ObjectiveFunction>

index_type num_collect::opt::firefly_optimizer< ObjectiveFunction >::dim_ {0}

private

Number of dimension.

Definition at line 380 of file firefly_optimizer.h.

◆ evaluations_

template<concepts::multi_variate_objective_function ObjectiveFunction>

index_type num_collect::opt::firefly_optimizer< ObjectiveFunction >::evaluations_ {0}

private

Number of function evaluations.

Definition at line 451 of file firefly_optimizer.h.

◆ initial_distribution_

template<concepts::multi_variate_objective_function ObjectiveFunction>

std::uniform_real_distribution<variable_scalar_type> num_collect::opt::firefly_optimizer< ObjectiveFunction >::initial_distribution_ {}

private

Distribution for the initial variables. (Uniform distribution from 0 to 1.)

Definition at line 436 of file firefly_optimizer.h.

◆ iterations_

template<concepts::multi_variate_objective_function ObjectiveFunction>

index_type num_collect::opt::firefly_optimizer< ObjectiveFunction >::iterations_ {0}

private

Number of iterations.

Definition at line 448 of file firefly_optimizer.h.

◆ lower_

template<concepts::multi_variate_objective_function ObjectiveFunction>

variable_type num_collect::opt::firefly_optimizer< ObjectiveFunction >::lower_ {}

private

Element-wise lower limit.

Definition at line 371 of file firefly_optimizer.h.

◆ max_evaluations_

template<concepts::multi_variate_objective_function ObjectiveFunction>

index_type num_collect::opt::firefly_optimizer< ObjectiveFunction >::max_evaluations_ {default_max_evaluations}

private

Maximum number of function evaluations.

Definition at line 457 of file firefly_optimizer.h.

◆ num_fireflies_

template<concepts::multi_variate_objective_function ObjectiveFunction>

index_type num_collect::opt::firefly_optimizer< ObjectiveFunction >::num_fireflies_ {default_num_fireflies}

private

Number of fireflies.

Definition at line 386 of file firefly_optimizer.h.

◆ obj_fun_

template<concepts::multi_variate_objective_function ObjectiveFunction>

objective_function_type num_collect::opt::firefly_optimizer< ObjectiveFunction >::obj_fun_

private

Objective function.

Definition at line 368 of file firefly_optimizer.h.

◆ opt_value_

template<concepts::multi_variate_objective_function ObjectiveFunction>

value_type num_collect::opt::firefly_optimizer< ObjectiveFunction >::opt_value_ {std::numeric_limits<value_type>::max()}

private

Current optimal value.

Definition at line 445 of file firefly_optimizer.h.

◆ opt_variable_

template<concepts::multi_variate_objective_function ObjectiveFunction>

variable_type num_collect::opt::firefly_optimizer< ObjectiveFunction >::opt_variable_ {}

private

Current optimal variable.

Definition at line 442 of file firefly_optimizer.h.

◆ random_coeff_

template<concepts::multi_variate_objective_function ObjectiveFunction>

variable_scalar_type num_collect::opt::firefly_optimizer< ObjectiveFunction >::random_coeff_ {default_random_coeff}

private

Coefficient of the random walk.

Note: This value is \(\alpha\) in [32].

Definition at line 419 of file firefly_optimizer.h.

◆ random_number_generator_

template<concepts::multi_variate_objective_function ObjectiveFunction>

random_number_generator_type num_collect::opt::firefly_optimizer< ObjectiveFunction >::random_number_generator_

private

Initial value:

{

std::random_device()()}

Random number generator.

Definition at line 431 of file firefly_optimizer.h.

◆ random_walk_distribution_

template<concepts::multi_variate_objective_function ObjectiveFunction>

std::normal_distribution<variable_scalar_type> num_collect::opt::firefly_optimizer< ObjectiveFunction >::random_walk_distribution_ {}

private

Distribution for random walk. (Standard normal distribution.)

Definition at line 439 of file firefly_optimizer.h.

◆ upper_

template<concepts::multi_variate_objective_function ObjectiveFunction>

variable_type num_collect::opt::firefly_optimizer< ObjectiveFunction >::upper_ {}

private

Element-wise upper limit.

Definition at line 374 of file firefly_optimizer.h.

◆ values_

template<concepts::multi_variate_objective_function ObjectiveFunction>

Eigen::VectorX<value_type> num_collect::opt::firefly_optimizer< ObjectiveFunction >::values_

private

Function values of the current variables.

Definition at line 428 of file firefly_optimizer.h.

◆ variable_changes_

template<concepts::multi_variate_objective_function ObjectiveFunction>

util::vector<variable_type> num_collect::opt::firefly_optimizer< ObjectiveFunction >::variable_changes_

private

Buffer of variable changes.

Definition at line 425 of file firefly_optimizer.h.

◆ variables_

template<concepts::multi_variate_objective_function ObjectiveFunction>

util::vector<variable_type> num_collect::opt::firefly_optimizer< ObjectiveFunction >::variables_

private

Current variables. (Positions of fireflies.)

Definition at line 422 of file firefly_optimizer.h.

◆ width_

template<concepts::multi_variate_objective_function ObjectiveFunction>

variable_type num_collect::opt::firefly_optimizer< ObjectiveFunction >::width_ {}

private

Element-wise width.

Definition at line 377 of file firefly_optimizer.h.

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

include/num_collect/opt/firefly_optimizer.h

Public Types

Public Member Functions

Private Member Functions

Static Private Member Functions

Private Attributes

Static Private Attributes

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ objective_function_type

◆ random_number_generator_type

◆ this_type

◆ value_type

◆ variable_scalar_type

◆ variable_type

Constructor & Destructor Documentation

◆ firefly_optimizer()

Member Function Documentation

◆ absorption_coeff()

◆ attractiveness_coeff()

◆ change_objective_function()

◆ configure_iteration_logger()

◆ correct_value_if_needed()

◆ evaluate_on()

◆ evaluations()

◆ init()

◆ is_stop_criteria_satisfied()

◆ iterate()

◆ iterations()

◆ max_evaluations()

◆ num_fireflies()

◆ opt_value()

◆ opt_variable()

◆ random_coeff()

◆ seed()

Member Data Documentation

◆ absorption_coeff_

◆ attractiveness_coeff_

◆ default_absorption_coeff

◆ default_attractiveness_coeff

◆ default_max_evaluations

◆ default_num_fireflies

◆ default_random_coeff

◆ dim_

◆ evaluations_

◆ initial_distribution_

◆ iterations_

◆ lower_

◆ max_evaluations_

◆ num_fireflies_

◆ obj_fun_

◆ opt_value_

◆ opt_variable_

◆ random_coeff_

◆ random_number_generator_

◆ random_walk_distribution_

◆ upper_

◆ values_

◆ variable_changes_

◆ variables_

◆ width_