CO_f1ecacderives from an earlier version of hctsa (the current version of hctsa names this feature as
first1e_acf_taufeature in catch22 computes the first 1/e crossing of the autocorrelation function of the time series. In hctsa, this can be computed as
first1e_acf_taucaptures the approximate scale of autocorrelation in a time series. This can be thought of as the number of steps into the future at which a value of the time series at the current point and that future point remain substantially (>1/e) correlated. For a continuous-time system, this statistic is high when the sampling rate is high relative to the timescale of the dynamics.
first1e_acf_tau = 1.
first1e_acf_tau = 6
first1e_acf_tau = 17
first1e_acf_tau = 176
CO_FirstMin_acin catch22 and matches the hctsa feature named
firstMin_acfcomputes the first minimum of the autocorrelation function. It exhibits similar behavior.