Characteristics of five different time series are shown. Column 1 shows the time series amplitudes. Column 2 represents the multiscale entropy, where the horizontal axis is the coarse-grained scale from 1 to 20. Column 3 is the multiscale time asymmetry value. The value of a in the lower right corner of the time asymmetry plot is the value of the time asymmetry index summed over scales 1 to 5. A nonzero time asymmetry value is a sufficient condition for nonlinearity of a time series.
Bosl et al. BMC Medicine 2011 9:18 doi:10.1186/1741-7015-9-18