iable is saved in a separate variable
(e.g., X_1, X_2, ..., Y_1, Y_2, ...). This is, e.g., the case when collecting
data using MouseTracker (Freeman &amp;amp;
Ambady, 2010). From this data.frame, mt_import_wide creates a
mousetrap data object containing the trajectories and additional data for
further processing within the mousetrap package. Specifically, it returns a
list that includes the trajectory data as an array (called
trajectories), and all other data as a data.frame (called
data). This data structu