Accelerometer data elaboration donkey pasture

Elaboration of raw acceleration data obtained from a tri-axial accelerometer used on donkeys at pasture. The acceleration data were grouped in different intervals of time called epochs, corresponding to the following time intervals: 15, 30, 60, 90, 120, 150, and 180 seconds. Mean, variance, and inverse of the coefficient of variation (obtained from the ratio between mean and standard deviation) for each axis and considering the trhee axis togheter were computed according to Watanabe et al. (2008).