Modified from the Ben Fulcher version of original code sampenc.m from http://physionet.org/physiotools/sampen/ http://www.physionet.org/physiotools/sampen/matlab/1.1/sampenc.m Code by DK Lake (dlake@virginia.edu), JR Moorman and Cao Hanqing.
References
cf. "Physiological time-series analysis using approximate entropy and sample entropy", J. S. Richman and J. R. Moorman, Am. J. Physiol. Heart Circ. Physiol., 278(6) H2039 (2000)
B.D. Fulcher and N.S. Jones. hctsa: A computational framework for automated time-series phenotyping using massive feature extraction. Cell Systems 5, 527 (2017).
B.D. Fulcher, M.A. Little, N.S. Jones Highly comparative time-series analysis: the empirical structure of time series and their methods. J. Roy. Soc. Interface 10, 83 (2013).