Figure 6
From: Data-driven spectral analysis for coordinative structures in periodic human locomotion
Extracted frequencies in four decomposition methods. Temporal frequency spectra averaged among all participants in relative frequency domain to the gait frequency for (a) column-type and (b) row-type Hankel DMDs, (c) companion-matrix DMD and (d) Fourier transformation for all walking speeds are shown. Pref. indicates preferred walking speed. The spectrum of each sequence was normalised so that the maximal norm is 1. For all walking speeds, column- and row-type Hankel DMDs visually obtained five harmonic frequencies. However, companion-matrix DMD visually shows only two harmonic frequencies. Averaged Fourier spectra were seemingly smoothed around the gait frequency.
