wavelet_analysis#

pymultifracs.wavelet_analysis(signal, wt_name='db3', j2=None, normalization=1)#

Compute wavelet coefficient and wavelet leaders.

Parameters:
signalndarray of float, shape (n_samples,) | (n_samples, n_realisations)

Time series to analyze.

wt_namestr

Name of the wavelet function to use, as defined in the pywavelet package [1]. The default value of 'db3' means Daubechies with 3 vanishing moments.

j2int | None

Upper bound of the scale range for which wavelet coefficients will be computed. If None, it will automatically be set to the highest value possible.

normalizationint

Norm to use on the wavelet coefficients, see notes for more details.

Returns:
WaveletDec

Wavelet coefficient representation of the signal.

Notes

When computing the wavelet coefficients, the values corrupted by border effects are set to NaN (np.nan).

This makes it easier to compute the wavelet leaders, since corrupted values will also be nan and can be easily discarded.

Note

Wavelet coefficients are usually L^1 normalized [2], which is achieved by setting normalization=1.

References