Figure 3.

(A) Non-negative matrix factorization (NMF) returns five basis shapes that explain 97.6% of the variance in the angle data. The graph shows an x-y coordinate representation of the modes with the resampled basis shapes in gray. (B) Angle representation of the basis shapes in (A; legend in C). (C) The fraction of the variance explained along the worm by including an increasing number of basis shapes suggests that the modes can each explain a different part of the worm well, in this case localized to the five major segments of the worm. (D) Bivariate histograms for the amplitudes of basis shapes (wild type worm, 15 min, frame rate: 30 Hz). Basis shapes 3, 4, 1 and 5 form incomplete rings, suggesting a more diffuse representation of the oscillatory sinusoidal crawling behavior using NMF.