colour.polynomial_expansion#
- colour.polynomial_expansion(a: ArrayLike, method: Literal['Cheung 2004', 'Finlayson 2015', 'Vandermonde'] | str = 'Cheung 2004', **kwargs: Any) NDArrayFloat [source]#
Perform polynomial expansion of given \(a\) array.
- Parameters:
a (ArrayLike) – \(a\) array to expand.
method (Literal['Cheung 2004', 'Finlayson 2015', 'Vandermonde'] | str) – Computation method.
degree – {
colour.characterisation.polynomial_expansion_Finlayson2015()
,colour.characterisation.polynomial_expansion_Vandermonde()
}, Expanded polynomial degree, must be one of [1, 2, 3, 4] forcolour.characterisation.polynomial_expansion_Finlayson2015()
definition.root_polynomial_expansion – {
colour.characterisation.polynomial_expansion_Finlayson2015()
}, Whether to use the root-polynomials set for the expansion.terms – {
colour.characterisation.matrix_augmented_Cheung2004()
}, Number of terms of the expanded polynomial.kwargs (Any)
- Returns:
Expanded \(a\) array.
- Return type:
References
[CWCR04], [FMH15], [WR04], [Wikipedia03f]
Examples
>>> RGB = np.array([0.17224810, 0.09170660, 0.06416938]) >>> polynomial_expansion(RGB) array([ 0.1722481..., 0.0917066..., 0.0641693...]) >>> polynomial_expansion(RGB, "Cheung 2004", terms=5) array([ 0.1722481..., 0.0917066..., 0.0641693..., 0.0010136..., 1...])