data.frame of dimension n * (p+2) containing the
p dimensional activity data for all n subject days.
The first two columns have to be ID and Day. ID can be
either character or numeric. Day has to be numeric indicating
the sequency of days within each subject.
window
since the caculation of M10 and L5 depends on the dimension of data, we need to include
window size as an argument. This function is a whole dataset
wrapper for RA.
method
character of "sum" or "average", function used to bin the data