emd.sift.mask_sift_second_layer#
- emd.sift.mask_sift_second_layer(IA, mask_freqs, sift_args=None)[source]#
Compute second layer IMFs using a mask sift.
Second layer IMFs are computed from the amplitude envelopes of a set of first layer IMFs [1].A single set of masks is applied across all IMFs with the highest frequency mask dropped for each successive first level IMF.
- Parameters:
- IAndarray
Input array containing a set of first layer IMFs
- mask_freqsfunction
Sift function to apply
- sift_argsdict
Dictionary of sift options to be passed into sift_func
- Returns:
- imf2ndarray
3D array [samples x first layer imfs x second layer imfs ] containing the second layer IMFs
References
[1]Huang, N. E., Hu, K., Yang, A. C. C., Chang, H.-C., Jia, D., Liang, W.-K., … Wu, Z. (2016). On Holo-Hilbert spectral analysis: a full informational spectral representation for nonlinear and non-stationary data. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 374(2065), 20150206. https://doi.org/10.1098/rsta.2015.0206