alibi.utils.approximation_methods

Constants

SUPPORTED_RIEMANN_METHODS

SUPPORTED_RIEMANN_METHODS: list = ['riemann_left', 'riemann_right', 'riemann_middle', 'riemann_trapezoid']

Built-in mutable sequence.

If no argument is given, the constructor creates a new empty list. The argument must be an iterable if specified.

SUPPORTED_METHODS

SUPPORTED_METHODS: list = ['riemann_left', 'riemann_right', 'riemann_middle', 'riemann_trapezoid', 'gau...

Built-in mutable sequence.

If no argument is given, the constructor creates a new empty list. The argument must be an iterable if specified.

Riemann

Inherits from: Enum

An enumeration.

Functions

approximation_parameters

approximation_parameters(method: str) -> Tuple[Callable[[.[<class 'int'>]], List[float]], Callable[[.[<class 'int'>]], List[float]]]

Retrieves parameters for the input approximation method.

Name	Type	Default	Description
method	str		The name of the approximation method. Currently supported only: 'riemann_*' and 'gausslegendre'. Check :py:data:alibi.utils.approximation_methods.SUPPORTED_RIEMANN_METHODS for all 'riemann_*' possible values.

Returns

• Type: Tuple[Callable[[.[<class 'int'>]], List[float]], Callable[[.[<class 'int'>]], List[float]]]

gauss_legendre_builders

gauss_legendre_builders() -> Tuple[Callable[[.[<class 'int'>]], List[float]], Callable[[.[<class 'int'>]], List[float]]]

np.polynomial.legendre function helps to compute step sizes and alpha coefficients using gauss-legendre quadrature rule. Since numpy returns the integration parameters in different scales we need to rescale them to adjust to the desired scale.

Gauss Legendre quadrature rule for approximating the integrals was originally proposed by [Xue Feng and her intern Hauroun Habeeb] (https://research.fb.com/people/feng-xue/).

Name	Type	Default	Description
n			The number of integration steps.

Returns

• Type: Tuple[Callable[[.[<class 'int'>]], List[float]], Callable[[.[<class 'int'>]], List[float]]]

riemann_builders

riemann_builders(method: alibi.utils.approximation_methods.Riemann = <Riemann.trapezoid: 4>) -> Tuple[Callable[[.[<class 'int'>]], List[float]], Callable[[.[<class 'int'>]], List[float]]]

Step sizes are identical and alphas are scaled in [0, 1].

Name	Type	Default	Description
method	alibi.utils.approximation_methods.Riemann	<Riemann.trapezoid: 4>	Riemann method: Riemann.left
n			The number of integration steps.

Returns

• Type: Tuple[Callable[[.[<class 'int'>]], List[float]], Callable[[.[<class 'int'>]], List[float]]]