Cross-approximate entropy Co-ApEn

Keywords— Diabetics, autonomic neuropathy, nonlinear, cross-approximate entropy (Co-ApEn). 

Cross-approximate entropy (Co-ApEn) is a measure the pattern similarity between two time series. No matter how the distribution of the signal pattern [17]. Low value of Co-ApEn indicates that two signals were similar, and high value of the Co-ApEn indicates that two signals are not similar. Co-ApEn can be estimated as follows. 

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