# Encoding: utf-8
"""Polynomial dispersion."""
import numpy.typing as npt
from .base_dispersion import Dispersion
[docs]
class Polynomial(Dispersion):
r"""Polynomial expression for the dielectric function.
Single parameters:
:e0: Defaults to 1.
Repeated parameters:
:f: Defaults to 0.
:e: Defaults to 0.
Output:
.. math::
\varepsilon(\lambda) =
\boldsymbol{\varepsilon_0} + \sum_j \boldsymbol{f}_j \cdot \lambda^{\boldsymbol{e}_j}
"""
single_params_template = {"e0": 1}
rep_params_template = {"f": 0, "e": 0}
def dielectric_function(self, lbda: npt.ArrayLike) -> npt.NDArray:
return self.single_params.get("e0") + sum(
c.get("f") * lbda ** c.get("e") for c in self.rep_params
)