计算脑电信号柯尔莫哥洛夫熵的python代码
时间: 2023-06-08 22:07:36 浏览: 122
以下是一个python代码示例,用于计算脑电信号的柯尔莫哥洛夫熵:
```
import numpy as np
from scipy.signal import welch
def spectral_entropy(signal, sf, method='fft', nperseg=None, normalize=False):
"""Spectral Entropy.
Parameters:
-----------
signal: list or np.array
One-dimensional time series of measurement values
sf: float
Sampling frequency
method: str
Spectral estimation method ::
'fft' : Fourier Transform (via scipy.signal.welch)
'welch': Welch periodogram (via scipy.signal.welch)
nperseg: str or int
Length of each Welch segment for FFT method.
If None, uses scipy default of 256 samples.
normalize: bool
If True, divides by log2 of frequency bin count
(some methods use raw spectral entropy, not normalized)
Returns:
--------
se: float
Spectral Entropy
Notes:
------
Spectral Entropy is defined to be the Shannon Entropy of the Power
Spectral Density (PSD) of the data after normalization of the PSD
to have unit area. This implementation first estimates the PSD
using welch or FFT, optionally normalizes the PSD, and then applies
the Shannon Entropy function.
To reduce memory requirements, the Welch method can be used to divide
the signal into segments.
This implementation is based on the spectral_entropy function from
the Entropy package authored by Raphael Vallat.
(https://raphaelvallat.com/entropy/build/html/index.html)
"""
# Compute and normalize power spectrum
if method == 'fft':
freqs, psd = welch(signal, sf, nperseg=nperseg)
elif method == 'welch':
freqs, psd = welch(signal, sf, nperseg=nperseg)
else:
raise ValueError('Method must be "fft" or "welch"')
psd_norm = np.divide(psd, psd.sum())
# Compute Shannon entropy
se = -np.multiply(psd_norm, np.log2(psd_norm)).sum()
# Normalize according to the spectral resolution
if normalize:
se /= np.log2(len(freqs))
return se
```
请注意,该代码的详细说明包括输入和输出的每个参数。此外,它使用scipy库中的welch函数来计算功率谱密度。该代码也可以使用其他信号源作为输入,而不仅仅是脑电信号。
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