scope.emd module
scope.emd.emd_energy_spectrum submodule
scope.emd.emd_modes submodule
- scope.emd.emd_modes.emd_modes(x, sd_thresh=0.0001)[source]
Returns set of EMD modes for a given timeseries x.
This function wraps sift function from emd library and returns a set of emd modes.
- Parameters:
x (numpy array) – Time series data
sift (floaf) – sifting factor
- Returns:
modes – Set of emd modes
- Return type:
numpy array
scope.emd.emd_noise_conf submodule
scope.emd.emd_period_energy submodule
- scope.emd.emd_period_energy.emd_period_energy(s, t, plot_spectrum=False)[source]
Calculates the dominant period and energy of input intrinsic mode function (IMF).
The function calculates the energy of IMF and performs the wavelet transform to compute its period and global wavelet spectrum. The global wavelet spectrum is fitted to estimate the dominant period.
- Parameters:
s (numpy array) – Input IMF
t (numpy array) – Time
plot_spectrum (bool, optional) – Plots the global wavelet spectrum and wavelet power spectrum. The default is False.
- Returns:
emd_period_energy_result –
- scope.emd.emd_period_energy.energy
Energy of the input IMF
- Type:
float
- scope.emd.emd_period_energy.dominant_period
Modal period associated with maximum power in global wavelet spectrum
- Type:
float
- scope.emd.emd_period_energy.dominant_period_err
Uncertainty of dominant modal period
- Type:
float
- scope.emd.emd_period_energy.period
Modal period
- Type:
numpy array
- scope.emd.emd_period_energy.global_ws
Global wavelet spectrum of input IMF
- Type:
numpy array
- scope.emd.emd_period_energy.best_fit
Values of the function that fits the global wavelet spectrum
- Type:
numpy array
- Return type:
dict
- scope.emd.emd_period_energy.fit_global_ws(period, global_ws)[source]
A global wavelet spectrum fitting algorithm.
This function fits the global wavelet spectrum of intrinsic mode function (IMF) by a Gaussian + quadratic function, in order to extract the dominant modal period from the position of Gaussian peak.
- Parameters:
period (numpy array) – Modal period
global_ws (numpy array) – Global wavelet spectrum of IMF
- Returns:
dominant_period (float) – Estimated dominant modal period
dominant_period_err (float) – Uncertainty of the dominant modal period
best_fit (numpy array) – The Gaussian + quadratic function that fits the global wavelet spectrum