48 lines
1.4 KiB
Python
48 lines
1.4 KiB
Python
from typing import Any
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import numpy as np
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from scipy.signal import savgol_filter
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from . import Points
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from .signals import Signal
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class BDS(Signal):
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"""
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Extension of Signal for dielectric spectroscopy purposes.
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"""
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def __init__(self, x, y, **kwargs: Any):
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super().__init__(x, y, **kwargs)
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if np.all(self._x > 0) and not np.allclose(np.diff(self._x), self._x[1]-self._x[0]):
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self.dx = self.x[1] / self.x[0]
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else:
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self.dx = self._x[1] - self._x[0]
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def __repr__(self) -> str:
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return f"{self.meta['mode']}: {self.name}"
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def derivative(self, window_length=9) -> Points:
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"""
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Calculates the derivative :math:`-\\frac{\\pi}{2}\\frac{d\\epsilon'}{d\\ln\\omega}`.
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To reduce :func:`scipy.signal.savgol_filter`
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Args:
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window_length (int)
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Returns:
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Points
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New Points instance with
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References:
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Wübbenhorst, M.; van Turnhout, J.: Analysis of complex dielectric spectra.
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I. One-dimensional derivative techniques and three-dimensional modelling.
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J. Non-Cryst. Solid. 305 (2002) https://doi.org/10.1016/s0022-3093(02)01086-4
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"""
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y = -savgol_filter(self.y[self.mask].real, window_length, 2, deriv=1) * np.pi / 2
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data = Points(x=self.x[self.mask], y=y)
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data.update(self.meta)
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return data
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