pyeeg.utils.signal_envelope

pyeeg.utils.signal_envelope(signal, srate, cutoff=20.0, method='hilbert', comp_factor=0.3333333333333333, resample=125, verbose=None)

Compute the broadband envelope of the input signal. Several methods are available:

• Hilbert -> abs -> low-pass (-> resample)

• Rectify -> low-pass (-> resample)

• subenvelopes -> sum

The envelope can also be compressed by raising to a certain power factor.

Parameters:

• signal (ndarray (nsamples,)) – 1-dimensional input signal

• srate (float) – Original sampling rate of the signal

• cutoff (float (default 20Hz)) – Cutoff frequency (transition will be 10 Hz) In Hz

• method (str {'hilbert', 'rectify', 'subs'}) – Method to be used

• comp_factor (float (default 1/3)) – Compression factor (final envelope = env**comp_factor)

• resample (float (default 125Hz)) – New sampling rate of envelope (must be 2*cutoff < .. <= srate) Explicitly set to False or None to skip resampling

Returns:

env – Envelope

Return type:

ndarray (nsamples_env,)