Download Surfaces here

top-left  -
Thin-plate splines extend all contours
to the maximum length.
mid-right  - The 13 curves of ‘golly’ are arranged to form a 3D-x,y,t  surface for each repetition.  An average x,y,t surface is then calculated.
 bottom-left -
A 2D-top down display of the average x,y,t surface shows y position at each x.  Blue is high and red low.
x, y, t ‘Surfaces’ represent the time-motion contours as a single entity.