Figure 2.

Coarse Graining Procedure. Given a time series $x_1, x_2\dots x_{i+2}$, we first create coarse-grained time series by averaging a growing number of data points in non-overlapping windows. Schematic illustration of the coarse-graining procedure in Multiscale Sample Entropy for scale τ = 2 in (a) and for scale τ = 3 in (b); data length of the trunk acceleration time series reduced, respectively to $\frac{N}{2}$ and $\frac{N}{3}$.