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Fig. 3. The velocity of each cell was analyzed in regard to speed and trajectory.
Examples show four types of analysis for four cells cultured from G.
mirabilis, two moving in straight lines and two moving in circles: (A) a
trajectory plot of (x,y) coordinates of the positions of four cells
over 20 min, beginning at the origin and rotated such that the first step is
along the y-axis (x=0); (B) speed histograms of the
frequency of instantaneous cell speeds; (C) autocorrelation analysis of cell
speed shows memory (correlation) and oscillation; and (D) cosine analysis
shows the magnitude of turning angles (
) made by the cell over
time.