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François Boulogne 2025-08-28 19:27:47 +02:00
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__version__ = '0.1.0' __version__ = '0.1.1'

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mysignal/phasefreq.py Normal file
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import warnings
import numpy as np
import pandas as pd
import pywt
from scipy.fft import fft, fftfreq
from scipy.signal import find_peaks, hilbert, butter, filtfilt, correlate
from scipy.stats import linregress
from scipy.optimize import curve_fit
def filter_signal_by_modes(time, signal, num_modes=1, bandwidth_factor=0.1):
"""
Filtre un signal pour extraire ses composantes fréquentielles dominantes.
Parameters:
time (array-like): Array contenant les données temporelles.
signal (array-like): Array contenant les données du signal.
num_modes (int): Nombre de modes fréquentiels à extraire.
Returns:
tuple: (filtered_signals, frequencies, time_filtered)
filtered_signals: Liste des signaux filtrés pour chaque mode
frequencies: Fréquences correspondantes à chaque mode
time_filtered: Temps après filtrage (même que l'entrée)
"""
# Convertir en arrays numpy
time = np.array(time)
signal = np.array(signal)
# Calculer la période d'échantillonnage et la fréquence
dt = np.mean(np.diff(time))
fs = 1 / dt
# Supprimer la composante DC
signal_clean = signal - np.mean(signal)
# Calculer la FFT
n = len(time)
fft_signal = fft(signal_clean)
freqs = fftfreq(n, dt)
# Prendre seulement les fréquences positives
positive_mask = freqs > 0
freqs_pos = freqs[positive_mask]
fft_pos = fft_signal[positive_mask]
# Trouver les pics dans le spectre
magnitude = np.abs(fft_pos)
peaks, _ = find_peaks(magnitude, height=0.1*np.max(magnitude))
peak_freqs = freqs_pos[peaks]
peak_mags = magnitude[peaks]
# Trier les pics par magnitude et sélectionner les num_modes plus importants
idx = np.argsort(peak_mags)[-num_modes:]
dominant_freqs = peak_freqs[idx]
# Trier les fréquences par ordre croissant
dominant_freqs.sort()
# Initialiser la liste des signaux filtrés
filtered_signals = []
# Pour chaque fréquence dominante, appliquer un filtre passe-bande
for freq in dominant_freqs:
# Définir la bande passante (10% de la fréquence centrale de chaque côté)
bandwidth = bandwidth_factor * freq
lowcut = freq - bandwidth
highcut = freq + bandwidth
# Éviter les fréquences négatives ou supérieures à la fréquence de Nyquist
nyq = 0.5 * fs
if lowcut <= 0:
lowcut = 0.01
if highcut >= nyq:
highcut = nyq - 0.01
# Créer le filtre Butterworth
low = lowcut / nyq
high = highcut / nyq
b, a = butter(4, [low, high], btype='band')
# Appliquer le filtre (filtfilt pour éviter le déphasage)
filtered_signal = filtfilt(b, a, signal_clean)
filtered_signals.append(filtered_signal)
# Le temps reste le même après filtrage
time_filtered = time
return filtered_signals, dominant_freqs, time_filtered
def analyze_signal_Hilbert(time, e_signal, s_signal):
"""
Analyzes the dominant frequencies, phase shift, time shift, and periods between two signals e_signal(t) and s_signal(t) from a DataFrame.
Uses Hilbert transform method for phase shift calculation (single mode only).
"""
# Extract signals and time
#time = df[time_column].values
#e_signal = df[e_signal_column].values
#s_signal = df[s_signal_column].values
# Calculate sampling period and rate
dt = np.mean(np.diff(time))
fs = 1 / dt
# Remove mean to eliminate DC component
e_signal_clean = e_signal - np.mean(e_signal)
s_signal_clean = s_signal - np.mean(s_signal)
# Compute FFT
n = len(time)
e_fft = fft(e_signal_clean)
s_fft = fft(s_signal_clean)
freqs = fftfreq(n, dt)
# Get positive frequencies only
positive_mask = freqs > 0
freqs_pos = freqs[positive_mask]
e_fft_pos = e_fft[positive_mask]
s_fft_pos = s_fft[positive_mask]
# Find dominant frequencies using peak detection
e_magnitude = np.abs(e_fft_pos)
s_magnitude = np.abs(s_fft_pos)
# Find peaks for e signal
e_peaks, _ = find_peaks(e_magnitude, height=0.1*np.max(e_magnitude))
e_peak_freqs = freqs_pos[e_peaks]
e_peak_mags = e_magnitude[e_peaks]
# Find peaks for s signal
s_peaks, _ = find_peaks(s_magnitude, height=0.1*np.max(s_magnitude))
s_peak_freqs = freqs_pos[s_peaks]
s_peak_mags = s_magnitude[s_peaks]
# Sort peaks by magnitude and select the top one
e_idx = np.argsort(e_peak_mags)[-1]
s_idx = np.argsort(s_peak_mags)[-1]
freq_e = e_peak_freqs[e_idx]
freq_s = s_peak_freqs[s_idx]
# Check if frequencies match within 1%
if np.abs(freq_e - freq_s) / ((freq_e + freq_s)/2) > 0.01:
raise ValueError("Frequency difference exceeds 1%. Phase shift cannot be determined.")
# Calculate mean frequency for phase shift calculation
mean_freq = (freq_e + freq_s) / 2
# Create a bandpass filter around the mean frequency
nyq = 0.5 * fs
low = (mean_freq - 0.1 * mean_freq) / nyq
high = (mean_freq + 0.1 * mean_freq) / nyq
if low <= 0:
low = 0.01
if high >= 1:
high = 0.99
b, a = butter(4, [low, high], btype='band')
# Filter both signals
e_filtered = filtfilt(b, a, e_signal_clean)
s_filtered = filtfilt(b, a, s_signal_clean)
# Apply Hilbert transform to filtered signals
e_analytic_filtered = hilbert(e_filtered)
s_analytic_filtered = hilbert(s_filtered)
# Extract phase
e_phase_filtered = np.unwrap(np.angle(e_analytic_filtered))
s_phase_filtered = np.unwrap(np.angle(s_analytic_filtered))
# Calculate phase difference
phase_diff = s_phase_filtered - e_phase_filtered
# Average phase difference over the stable part of the signal
n_stable = len(phase_diff) // 4
stable_phase_diff = phase_diff[n_stable:-n_stable]
# Calculate mean phase difference
mean_phase_diff = np.mean(stable_phase_diff)
# Normalize to [-π, π]
mean_phase_diff = np.arctan2(np.sin(mean_phase_diff), np.cos(mean_phase_diff))
# Convert to degrees
phase_diff_deg = np.degrees(mean_phase_diff)
# Calculate time shift
time_shift = mean_phase_diff / (2 * np.pi * mean_freq)
# Calculate periods
period_e = 1 / freq_e
period_s = 1 / freq_s
print(f'phase = {mean_phase_diff}')
return (period_e, period_s, freq_e, freq_s,
mean_phase_diff, phase_diff_deg, time_shift)
def analyze_signal_sinfit(time, e_signal, s_signal):
"""
Analyzes the dominant frequencies, phase shift, time shift, and periods between two signals e_signal(t) and s_signal(t) from a DataFrame.
Uses curve fitting method for phase shift calculation (single mode only).
"""
# Extract signals and time
#time = df[time_column].values
#e_signal = df[e_signal_column].values
#s_signal = df[s_signal_column].values
# Calculate sampling period and rate
dt = np.mean(np.diff(time))
fs = 1 / dt
# Remove mean to eliminate DC component
e_signal_clean = e_signal - np.mean(e_signal)
s_signal_clean = s_signal - np.mean(s_signal)
# Compute FFT
n = len(time)
e_fft = fft(e_signal_clean)
s_fft = fft(s_signal_clean)
freqs = fftfreq(n, dt)
# Get positive frequencies only
positive_mask = freqs > 0
freqs_pos = freqs[positive_mask]
e_fft_pos = e_fft[positive_mask]
s_fft_pos = s_fft[positive_mask]
# Find dominant frequencies using peak detection
e_magnitude = np.abs(e_fft_pos)
s_magnitude = np.abs(s_fft_pos)
# Find peaks for e signal
e_peaks, _ = find_peaks(e_magnitude, height=0.1*np.max(e_magnitude))
e_peak_freqs = freqs_pos[e_peaks]
e_peak_mags = e_magnitude[e_peaks]
# Find peaks for s signal
s_peaks, _ = find_peaks(s_magnitude, height=0.1*np.max(s_magnitude))
s_peak_freqs = freqs_pos[s_peaks]
s_peak_mags = s_magnitude[s_peaks]
# Sort peaks by magnitude and select the top one
e_idx = np.argsort(e_peak_mags)[-1]
s_idx = np.argsort(s_peak_mags)[-1]
freq_e = e_peak_freqs[e_idx]
freq_s = s_peak_freqs[s_idx]
# Check if frequencies match within 1%
if np.abs(freq_e - freq_s) / ((freq_e + freq_s)/2) > 0.01:
raise ValueError("Frequency difference exceeds 1%. Phase shift cannot be determined.")
# Calculate mean frequency for phase shift calculation
mean_freq = (freq_e + freq_s) / 2
# Define sine function for fitting
def sine_func(t, A, phi, offset):
return A * np.sin(2 * np.pi * mean_freq * t + phi) + offset
# Fit sine wave to e signal
try:
popt_e, _ = curve_fit(sine_func, time, e_signal,
p0=[np.std(e_signal), 0, np.mean(e_signal)],
bounds=([0, -np.pi, -np.inf], [np.inf, np.pi, np.inf]))
except:
popt_e = [np.std(e_signal), 0, np.mean(e_signal)]
# Fit sine wave to s signal
try:
popt_s, _ = curve_fit(sine_func, time, s_signal,
p0=[np.std(s_signal), 0, np.mean(s_signal)],
bounds=([0, -np.pi, -np.inf], [np.inf, np.pi, np.inf]))
except:
popt_s = [np.std(s_signal), 0, np.mean(s_signal)]
# Calculate phase difference
phase_diff = popt_s[1] - popt_e[1]
# Normalize to [-π, π]
phase_diff = np.arctan2(np.sin(phase_diff), np.cos(phase_diff))
# Convert to degrees
phase_diff_deg = np.degrees(phase_diff)
# Calculate time shift
time_shift = phase_diff / (2 * np.pi * mean_freq)
# Calculate periods
period_e = 1 / freq_e
period_s = 1 / freq_s
print(f'phase = {phase_diff}')
return (period_e, period_s, freq_e, freq_s,
phase_diff, phase_diff_deg, time_shift)
def analyze_signal_cross_correlation(time, e_signal, s_signal):
"""
Analyzes signals using cross-correlation method for phase shift calculation (single mode only).
"""
# Extract signals and time
#time = df[time_column].values
#e_signal = df[e_signal_column].values
#s_signal = df[s_signal_column].values
# Calculate sampling period and rate
dt = np.mean(np.diff(time))
fs = 1 / dt
# Remove mean to eliminate DC component
e_signal_clean = e_signal - np.mean(e_signal)
s_signal_clean = s_signal - np.mean(s_signal)
# Compute FFT
n = len(time)
e_fft = fft(e_signal_clean)
s_fft = fft(s_signal_clean)
freqs = fftfreq(n, dt)
# Get positive frequencies only
positive_mask = freqs > 0
freqs_pos = freqs[positive_mask]
e_fft_pos = e_fft[positive_mask]
s_fft_pos = s_fft[positive_mask]
# Find dominant frequencies using peak detection
e_magnitude = np.abs(e_fft_pos)
s_magnitude = np.abs(s_fft_pos)
# Find peaks for e signal
e_peaks, _ = find_peaks(e_magnitude, height=0.1*np.max(e_magnitude))
e_peak_freqs = freqs_pos[e_peaks]
e_peak_mags = e_magnitude[e_peaks]
# Find peaks for s signal
s_peaks, _ = find_peaks(s_magnitude, height=0.1*np.max(s_magnitude))
s_peak_freqs = freqs_pos[s_peaks]
s_peak_mags = s_magnitude[s_peaks]
# Sort peaks by magnitude and select the top one
e_idx = np.argsort(e_peak_mags)[-1]
s_idx = np.argsort(s_peak_mags)[-1]
freq_e = e_peak_freqs[e_idx]
freq_s = s_peak_freqs[s_idx]
# Check if frequencies match within 1%
if np.abs(freq_e - freq_s) / ((freq_e + freq_s)/2) > 0.01:
raise ValueError("Frequency difference exceeds 1%. Phase shift cannot be determined.")
# Calculate mean frequency for phase shift calculation
mean_freq = (freq_e + freq_s) / 2
# Create a bandpass filter around the mean frequency
nyq = 0.5 * fs
low = (mean_freq - 0.1 * mean_freq) / nyq
high = (mean_freq + 0.1 * mean_freq) / nyq
if low <= 0:
low = 0.01
if high >= 1:
high = 0.99
b, a = butter(4, [low, high], btype='band')
# Filter both signals
e_filtered = filtfilt(b, a, e_signal_clean)
s_filtered = filtfilt(b, a, s_signal_clean)
# Compute cross-correlation
correlation = correlate(s_filtered, e_filtered, mode='full')
lags = np.arange(-len(e_filtered) + 1, len(e_filtered))
# Find the lag with maximum correlation
max_lag = lags[np.argmax(correlation)]
# Calculate time shift
time_shift = max_lag * dt
# Calculate phase shift
phase_diff = 2 * np.pi * mean_freq * time_shift
# Normalize to [-π, π]
phase_diff = np.arctan2(np.sin(phase_diff), np.cos(phase_diff))
# Convert to degrees
phase_diff_deg = np.degrees(phase_diff)
# Calculate periods
period_e = 1 / freq_e
period_s = 1 / freq_s
print(f'phase = {phase_diff}')
return (period_e, period_s, freq_e, freq_s,
phase_diff, phase_diff_deg, time_shift)
def analyze_signal_wavelet(time, e_signal, s_signal):
"""
Analyzes signals using wavelet transform for phase shift calculation (single mode only).
"""
# Extract signals and time
#time = df[time_column].values
#e_signal = df[e_signal_column].values
#s_signal = df[s_signal_column].values
# Calculate sampling period and rate
dt = np.mean(np.diff(time))
fs = 1 / dt
# Remove mean to eliminate DC component
e_signal_clean = e_signal - np.mean(e_signal)
s_signal_clean = s_signal - np.mean(s_signal)
# Compute FFT
n = len(time)
e_fft = fft(e_signal_clean)
s_fft = fft(s_signal_clean)
freqs = fftfreq(n, dt)
# Get positive frequencies only
positive_mask = freqs > 0
freqs_pos = freqs[positive_mask]
e_fft_pos = e_fft[positive_mask]
s_fft_pos = s_fft[positive_mask]
# Find dominant frequencies using peak detection
e_magnitude = np.abs(e_fft_pos)
s_magnitude = np.abs(s_fft_pos)
# Find peaks for e signal
e_peaks, _ = find_peaks(e_magnitude, height=0.1*np.max(e_magnitude))
e_peak_freqs = freqs_pos[e_peaks]
e_peak_mags = e_magnitude[e_peaks]
# Find peaks for s signal
s_peaks, _ = find_peaks(s_magnitude, height=0.1*np.max(s_magnitude))
s_peak_freqs = freqs_pos[s_peaks]
s_peak_mags = s_magnitude[s_peaks]
# Sort peaks by magnitude and select the top one
e_idx = np.argsort(e_peak_mags)[-1]
s_idx = np.argsort(s_peak_mags)[-1]
freq_e = e_peak_freqs[e_idx]
freq_s = s_peak_freqs[s_idx]
# Check if frequencies match within 1%
if np.abs(freq_e - freq_s) / ((freq_e + freq_s)/2) > 0.01:
raise ValueError("Frequency difference exceeds 1%. Phase shift cannot be determined.")
# Calculate mean frequency for phase shift calculation
mean_freq = (freq_e + freq_s) / 2
# Perform continuous wavelet transform
scales = np.arange(1, 128)
coefficients_e, frequencies_e = pywt.cwt(e_signal_clean, scales, 'morl', sampling_period=dt)
coefficients_s, frequencies_s = pywt.cwt(s_signal_clean, scales, 'morl', sampling_period=dt)
# Find the scale index closest to the mean frequency
scale_idx = np.argmin(np.abs(frequencies_e - mean_freq))
# Extract the wavelet coefficients at this scale
coeffs_e = coefficients_e[scale_idx, :]
coeffs_s = coefficients_s[scale_idx, :]
# Calculate the instantaneous phase using the Hilbert transform
analytic_e = hilbert(coeffs_e)
analytic_s = hilbert(coeffs_s)
phase_e = np.unwrap(np.angle(analytic_e))
phase_s = np.unwrap(np.angle(analytic_s))
# Calculate phase difference
phase_diff = phase_s - phase_e
# Average phase difference over the stable part of the signal
n_stable = len(phase_diff) // 4
stable_phase_diff = phase_diff[n_stable:-n_stable]
# Calculate mean phase difference
mean_phase_diff = np.mean(stable_phase_diff)
# Normalize to [-π, π]
mean_phase_diff = np.arctan2(np.sin(mean_phase_diff), np.cos(mean_phase_diff))
# Convert to degrees
phase_diff_deg = np.degrees(mean_phase_diff)
# Calculate time shift
time_shift = mean_phase_diff / (2 * np.pi * mean_freq)
# Calculate periods
period_e = 1 / freq_e
period_s = 1 / freq_s
print(f'phase = {mean_phase_diff}')
return (period_e, period_s, freq_e, freq_s,
mean_phase_diff, phase_diff_deg, time_shift)

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numpy numpy
scipy scipy
pandas pandas
PyWavelets