The Discrete class is a basic Term that represents a discrete membership function. More...

#include <Discrete.h>

Inheritance diagram for fl::Discrete:

Collaboration diagram for fl::Discrete:

Public Types
typedef std::pair< scalar, scalar >	Pair

Public Member Functions
	Discrete (const std::string &name="", const std::vector< Pair > &xy=std::vector< Pair >(), scalar height=1.0)

virtual	~Discrete () FL_IOVERRIDE

virtual std::string	className () const FL_IOVERRIDE
	Returns the name of the class of the term. More...

virtual std::string	parameters () const FL_IOVERRIDE
	Returns the parameters of the term as `x1 y1 xn yn [height]` More...

virtual void	configure (const std::string &parameters) FL_IOVERRIDE
	Configures the term with the parameters given as `x1 y1 xn yn [height]` More...

virtual void	sort ()
	Ascendantly sorts the pairs of values in this Discrete term by the \(x\)-coordinate. More...

virtual Complexity	complexity () const FL_IOVERRIDE
	Computes the estimated complexity of evaluating the membership function. More...

virtual scalar	membership (scalar x) const FL_IOVERRIDE
	Computes the membership function evaluated at \(x\) by using binary search to find the lower and upper bounds of \(x\) and then linearly interpolating the membership function between the bounds. More...

virtual void	setXY (const std::vector< Pair > &pairs)
	Sets the vector of pairs defining the discrete membership function. More...

virtual const std::vector< Pair > &	xy () const
	Gets an immutable vector of pairs defining the discrete membership function. More...

virtual std::vector< Pair > &	xy ()
	Gets a mutable vector of pairs defining the discrete membership function. More...

virtual const Pair &	xy (std::size_t index) const
	Gets the immutable pair \((x_i,y_i)\) at index \(i\). More...

virtual Pair &	xy (std::size_t index)
	Gets the mutable pair \((x_i,y_i)\) at index \(i\). More...

virtual std::vector< scalar >	x () const
	Creates, fills and returns a vector containing the \(x\) values. More...

virtual scalar	x (std::size_t index) const
	Gets the \(x\) value at the given index. More...

virtual scalar &	x (std::size_t index)
	Gets the reference to the \(x\) value at the given index. More...

virtual std::vector< scalar >	y () const
	Creates, fills and returns a vector containing the \(y\) values. More...

virtual scalar	y (std::size_t index) const
	Gets the \(y\) value at the given index. More...

virtual scalar &	y (std::size_t index)
	Gets the reference to the \(y\) value at the given index. More...

virtual Discrete *	clone () const FL_IOVERRIDE
	Creates a clone of the term. More...

Public Member Functions inherited from fl::Term
	Term (const std::string &name="", scalar height=1.0)

virtual	~Term ()

virtual void	setName (const std::string &name)
	Sets the name of the term. More...

virtual std::string	getName () const
	Gets the name of the term. More...

virtual void	setHeight (scalar height)
	Sets the height of the term. More...

virtual scalar	getHeight () const
	Gets the height of the term. More...

virtual std::string	toString () const
	Returns the representation of the term in the FuzzyLite Language. More...

virtual void	updateReference (const Engine *engine)
	Updates the references (if any) to point to the current engine (useful when cloning engines or creating terms within Importer objects. More...

Static Public Member Functions
static void	sort (std::vector< Pair > &pairs)
	Ascendantly sorts the given pairs of values by the \(x\)-value, as it is required by the Discrete term. More...

static std::vector< scalar >	toVector (const std::vector< Pair > &xy)
	Creates a vector of fl::scalar from a vector of Pair given in the form \(\left(\{x_1,y_1\},...,\{x_n,y_n\}\right)\). More...

static std::vector< Pair >	toPairs (const std::vector< scalar > &xy)
	Creates a vector of Pair from a vector of fl::scalar given in the form \((x_1,y_1,...,x_n,y_n)\). More...

static std::vector< Pair >	toPairs (const std::vector< scalar > &xy, scalar missingValue) FL_INOEXCEPT
	Creates a vector of Pair from a vector of fl::scalar given in the form \((x_1,y_1,...,x_n,y_n)\). More...

static std::string	formatXY (const std::vector< Pair > &xy, const std::string &prefix="(", const std::string &innerSeparator=",", const std::string &suffix=")", const std::string &outerSeparator=" ")
	Formats a vector of Pair into a std::string in the form \((x_1,y_1) ... (x_n,y_n)\). More...

static Discrete *	discretize (const Term *term, scalar start, scalar end, int resolution=IntegralDefuzzifier::defaultResolution(), bool boundedMembershipFunction=true)
	Discretizes the given term. More...

static Term *	constructor ()

template<typename T >
static Discrete *	create (const std::string &name, int argc, T x1, T y1,...)
	Creates a Discrete term from a variadic set of values. More...

Additional Inherited Members
Protected Attributes inherited from fl::Term
scalar	_height

Detailed Description

The Discrete class is a basic Term that represents a discrete membership function.

The pairs of values in any Discrete term must be sorted ascendently because the membership function is computed using binary search to find the lower and upper bounds of \(x\).

Author: Juan Rada-Vilela, Ph.D.

See also: Term; Variable

Since: 4.0

Definition at line 42 of file Discrete.h.

Member Typedef Documentation

◆ Pair

typedef std::pair<scalar, scalar> fl::Discrete::Pair

Definition at line 44 of file Discrete.h.

Constructor & Destructor Documentation

◆ Discrete()

fl::Discrete::Discrete	(	const std::string &	name = `""`,
		const std::vector< Pair > &	xy = `std::vector< Pair >()`,
		scalar	height = `1.0`
	)

explicit

◆ ~Discrete()

virtual fl::Discrete::~Discrete ( )

virtual

Member Function Documentation

◆ className()

virtual std::string fl::Discrete::className ( ) const

virtual

Returns the name of the class of the term.

Returns: the name of the class of the term

Implements fl::Term.

◆ clone()

virtual Discrete* fl::Discrete::clone ( ) const

virtual

Creates a clone of the term.

Returns: a clone of the term

Implements fl::Term.

◆ complexity()

virtual Complexity fl::Discrete::complexity ( ) const

virtual

Computes the estimated complexity of evaluating the membership function.

Returns: the estimated complexity of evaluating the membership function

Implements fl::Term.

◆ configure()

virtual void fl::Discrete::configure ( const std::string & parameters )

virtual

Configures the term with the parameters given as x1 y1 xn yn [height]

Parameters

parameters as x1 y1 xn yn [height]

Implements fl::Term.

◆ constructor()

static Term* fl::Discrete::constructor ( )

static

◆ create()

template<typename T >

Discrete * fl::Discrete::create	(	const std::string &	name,
		int	argc,
		T	x1,
		T	y1,
			...
	)

inlinestatic

Creates a Discrete term from a variadic set of values.

Beware: this method is unsafe and must be used with care by ensuring:

the value argc correctly and exactly determines the number of values passed,

the data type of each variadic arguments is the same, e.g., \((1.0, 2.0, 3.0)\) are all fl::scalar, whereas in \((1.0, 2, 3.0)\) the second term is an integer, which will cause memory access issues due to the difference in size between int and fl::scalar.

Parameters

name	is the name of the resulting term
argc	is the number of values passed
x1	is the \(x\) value of the first Pair
y1	is the \(y\) value of the first Pair
...	are the remaining pairs of values \(x_i\) and \(y_i\)

Returns: a new Discrete term with the given parameters

Definition at line 259 of file Discrete.h.

◆ discretize()

static Discrete* fl::Discrete::discretize	(	const Term *	term,
		scalar	start,
		scalar	end,
		int	resolution = `IntegralDefuzzifier::defaultResolution()`,
		bool	boundedMembershipFunction = `true`
	)

static

Discretizes the given term.

Parameters

term	is the term to discretize
start	is the value from which discretization starts
end	is the value at which discretization ends
resolution	is the number of equally-distributed samples to perform between start and end
boundedMembershipFunction	indicates whether to ensure that \(\mu(x)\in[0.0,1.0]\)

Returns: a Discrete term that approximates the given term

◆ formatXY()

static std::string fl::Discrete::formatXY	(	const std::vector< Pair > &	xy,
		const std::string &	prefix = `"("`,
		const std::string &	innerSeparator = `","`,
		const std::string &	suffix = `")"`,
		const std::string &	outerSeparator = `" "`
	)

static

Formats a vector of Pair into a std::string in the form \((x_1,y_1) ... (x_n,y_n)\).

Parameters

xy	is the vector of Pair
prefix	indicates the prefix of a Pair, e.g., `(` results in \((x_i\)
innerSeparator	indicates the separator between \(x\) and \(y\), e.g., `,` results in \(x_i,y_i\)
suffix	indicates the postfix of a Pair, e.g., `]` results in \(y_i]\)
outerSeparator	indicates the separator between Pair, e.g., `;` results in \((x_i,y_i);(x_j,y_j)\)

Returns: a formatted string containing the pairs of \((x,y)\) values

◆ membership()

virtual scalar fl::Discrete::membership ( scalar x ) const

virtual

Computes the membership function evaluated at \(x\) by using binary search to find the lower and upper bounds of \(x\) and then linearly interpolating the membership function between the bounds.

Parameters

x

Returns: \( \dfrac{h (y_{\max} - y_{\min})}{(x_{\max}- x_{\min})} (x - x_{\min}) + y_{\min}\)

where \(h\) is the height of the Term, \(x_{\min}\) and \(x_{\max}\)is are the lower and upper limits of \(x\) in xy (respectively), \(y_{\min}\) and \(y_{\max}\)is are the membership functions of \(\mu(x_{\min})\) and \(\mu(x_{\max})\) (respectively)

Implements fl::Term.

◆ parameters()

virtual std::string fl::Discrete::parameters ( ) const

virtual

Returns the parameters of the term as x1 y1 xn yn [height]

Returns: x1 y1 xn yn [height]

Implements fl::Term.

◆ setXY()

virtual void fl::Discrete::setXY ( const std::vector< Pair > & pairs )

virtual

Sets the vector of pairs defining the discrete membership function.

Parameters

pairs is the vector of pairs defining the discrete membership function

◆ sort() [1/2]

static void fl::Discrete::sort ( std::vector< Pair > & pairs )

static

Ascendantly sorts the given pairs of values by the \(x\)-value, as it is required by the Discrete term.

Parameters

pairs is a vector of pairs of values in the form \((x,y)\)

◆ sort() [2/2]

virtual void fl::Discrete::sort ( )

virtual

Ascendantly sorts the pairs of values in this Discrete term by the \(x\)-coordinate.

◆ toPairs() [1/2]

static std::vector<Pair> fl::Discrete::toPairs ( const std::vector< scalar > & xy )

static

Creates a vector of Pair from a vector of fl::scalar given in the form \((x_1,y_1,...,x_n,y_n)\).

Parameters

xy	is a vector of fl::scalar given as \((x_1,y_1,...,x_n,y_n)\)

Returns: a vector of Pair in the form \(\left(\{x_1,y_1\},...,\{x_n,y_n\}\right)\)

Exceptions

fl::Exception if a value is missing, that is, if the length of \(xy\) is odd: \(|xy|\mod 2 = 1\)

◆ toPairs() [2/2]

static std::vector<Pair> fl::Discrete::toPairs	(	const std::vector< scalar > &	xy,
		scalar	missingValue
	)

static

Creates a vector of Pair from a vector of fl::scalar given in the form \((x_1,y_1,...,x_n,y_n)\).

Parameters

xy	is a vector of fl::scalar given as \((x_1,y_1,...,x_n,y_n)\) possibly missing a value
missingValue	is the replacement in the case a value is missing from \(xy\)

Returns: a vector of Pair in the form \(\left(\{x_1,y_1\},...,\{x_n,y_n\}\right)\)

◆ toVector()

static std::vector<scalar> fl::Discrete::toVector ( const std::vector< Pair > & xy )

static

Creates a vector of fl::scalar from a vector of Pair given in the form \(\left(\{x_1,y_1\},...,\{x_n,y_n\}\right)\).

Parameters

xy	is the vector of Pair

Returns: a vector of fl::scalar as \((x_1,y_1,...,x_n,y_n)\)

◆ x() [1/3]

virtual std::vector<scalar> fl::Discrete::x ( ) const

virtual

Creates, fills and returns a vector containing the \(x\) values.

Returns: a vector containing the \(x\) values

◆ x() [2/3]

virtual scalar fl::Discrete::x ( std::size_t index ) const

virtual

Gets the \(x\) value at the given index.

Returns: the \(x\) value at the given index

◆ x() [3/3]

virtual scalar& fl::Discrete::x ( std::size_t index )

virtual

Gets the reference to the \(x\) value at the given index.

Returns: the reference to the \(x\) value at the given index

◆ xy() [1/4]

virtual const std::vector<Pair>& fl::Discrete::xy ( ) const

virtual

Gets an immutable vector of pairs defining the discrete membership function.

Returns: an immutable vector of pairs defining the discrete membership function

◆ xy() [2/4]

virtual std::vector<Pair>& fl::Discrete::xy ( )

virtual

Gets a mutable vector of pairs defining the discrete membership function.

Returns: a mutable vector of pairs defining the discrete membership function

◆ xy() [3/4]

virtual const Pair& fl::Discrete::xy ( std::size_t index ) const

virtual

Gets the immutable pair \((x_i,y_i)\) at index \(i\).

Parameters

index is the index \(i\)

Returns: the immutable pair \((x_i,y_i)\)

◆ xy() [4/4]

virtual Pair& fl::Discrete::xy ( std::size_t index )

virtual

Gets the mutable pair \((x_i,y_i)\) at index \(i\).

Parameters

index is the index \(i\)

Returns: a mutable pair \((x_i,y_i)\)

◆ y() [1/3]

virtual std::vector<scalar> fl::Discrete::y ( ) const

virtual

Creates, fills and returns a vector containing the \(y\) values.

Returns: a vector containing the \(y\) values

◆ y() [2/3]

virtual scalar fl::Discrete::y ( std::size_t index ) const

virtual

Gets the \(y\) value at the given index.

Parameters

index is the index

Returns: the \(y\) value at the given index

◆ y() [3/3]

virtual scalar& fl::Discrete::y ( std::size_t index )

virtual

Gets the reference to the \(y\) value at the given index.

Parameters

index is the index

Returns: the reference to the \(y\) value at the given index

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

fuzzylite/fl/term/Discrete.h

Public Types

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ Pair

Constructor & Destructor Documentation

◆ Discrete()

◆ ~Discrete()

Member Function Documentation

◆ className()

◆ clone()

◆ complexity()

◆ configure()

◆ constructor()

◆ create()

◆ discretize()

◆ formatXY()

◆ membership()

◆ parameters()

◆ setXY()

◆ sort() [1/2]

◆ sort() [2/2]

◆ toPairs() [1/2]

◆ toPairs() [2/2]

◆ toVector()

◆ x() [1/3]

◆ x() [2/3]

◆ x() [3/3]

◆ xy() [1/4]

◆ xy() [2/4]

◆ xy() [3/4]

◆ xy() [4/4]

◆ y() [1/3]

◆ y() [2/3]

◆ y() [3/3]