Identify windows in which the phone may have been rotated or flipped, as indicated by a gravity vector
tag_outlier_windows(gravity, window_length, window_overlap)
| gravity | A dataframe with gravity vectors for columns  | 
    
|---|---|
| window_length | The number of samples per window.  | 
    
| window_overlap | Fraction in the interval [0, 1) specifying the amount of window overlap during the windowing transformation.  | 
    
Rotations errors for each window.