Term

Term

Bases: ABC

Abstract class for linguistic terms.

The linguistic terms in this library can be divided into four groups, namely basic, extended, edge, and function.

basic/function	extended	edge
fuzzylite.term.Discrete	fuzzylite.term.Bell	fuzzylite.term.Arc
fuzzylite.term.Rectangle	fuzzylite.term.Cosine	fuzzylite.term.Binary
fuzzylite.term.SemiEllipse	fuzzylite.term.Gaussian	fuzzylite.term.Concave
fuzzylite.term.Triangle	fuzzylite.term.GaussianProduct	fuzzylite.term.Ramp
fuzzylite.term.Trapezoid	fuzzylite.term.PiShape	fuzzylite.term.Sigmoid
fuzzylite.term.Constant	fuzzylite.term.SigmoidDifference	fuzzylite.term.SShape - fuzzylite.term.ZShape
fuzzylite.term.Linear	fuzzylite.term.SigmoidProduct	fuzzylite.term.SShape
fuzzylite.term.Function	fuzzylite.term.Spike	fuzzylite.term.ZShape

related

• fuzzylite.variable.Variable
• fuzzylite.variable.InputVariable
• fuzzylite.variable.OutputVariable

Attributes

height instance-attribute

height = height

name instance-attribute

name = name

Functions

__init__

__init__(name: str = '', height: float = 1.0) -> None

Constructor.

Parameters:

Name	Type	Description	Default
name	str	name of the term	''
height	float	height of the term.	1.0

__repr__

__repr__() -> str

Return the code to construct the term in Python.

Returns:

Type	Description
str	code to construct the term in Python.

__str__

__str__() -> str

Return the code to construct the term in the FuzzyLite Language.

Returns:

Type	Description
str	code to construct the term in the FuzzyLite Language.

_parameters

_parameters(*args: object) -> str

Concatenate the arguments and the height.

Parameters:

Name	Type	Description	Default
*args	object	arguments to configure the term	()

Returns:

Type	Description
str	parameters concatenated and an optional height at the end.

_parse

_parse(required: int, parameters: str, *, height: bool = True) -> list[float]

Parse the required values from the parameters.

Parameters:

Name	Type	Description	Default
required	int	number of values to parse	required
parameters	str	text containing the values	required
height	bool	whether parameters contains an extra value for the height of the term	True

Returns:

Type	Description
list[float]	list of floating-point values parsed from the parameters.

configure

configure(parameters: str) -> None

Configure the term with the parameters.

The parameters is a list of space-separated values, with an optional value at the end to set the height (defaults to 1.0 if absent)

Parameters:

Name	Type	Description	Default
parameters	str	space-separated parameter values to configure the term.	required

discretize

discretize(start: float, end: float, resolution: int = 10, midpoints: bool = True) -> Discrete

Discretize the term.

Parameters:

Name	Type	Description	Default
start	float	start of the range	required
end	float	end of the range	required
resolution	int	number of points to discretize	10
midpoints	bool	use midpoints method or include start and end.	True

related

• fuzzylite.operation.Operation.midpoints
• numpy.linspace

is_monotonic

is_monotonic() -> bool

Return whether the term is monotonic.

Returns:

Type	Description
bool	False.

membership abstractmethod

membership(x: Scalar) -> Scalar

Compute the membership function value of \(x\).

Parameters:

Name	Type	Description	Default
x	Scalar	scalar	required

Returns:

Type	Description
Scalar	membership function value \(\mu(x)\).

parameters

parameters() -> str

Return the parameters of the term.

Returns:

Type	Description
str	list of space-separated parameters of the term.

tsukamoto

tsukamoto(y: Scalar) -> Scalar

Compute the tsukamoto value of the monotonic term for activation degree \(y\).

Equation

\(g(y) = \{ z \in\mathbb{R} : \mu(z) = y \}\)

Warning

Raises RuntimeError because the term does not support Tsukamoto

Parameters:

Name	Type	Description	Default
y	Scalar	activation degree	required

Raises:

Type	Description
RuntimeError	because the term does not support Tsukamoto

update_reference

update_reference(engine: Engine | None) -> None

Update the reference (if any) to the engine the term belongs to.

Parameters:

Name	Type	Description	Default
engine	Engine | None	engine to which the term belongs to.	required