fold_dt: Widens the dataset to take into account the t previous time slices
Description
This function will widen the dataset to put the t previous time slices
in each row, so that it can be used to learn temporal arcs in the second
phase of the dmmhc.
Usage
fold_dt(dt, size)
Value
the extended data.table
Arguments
dt
the data.table to be treated
size
number of time slices to unroll. Markovian 1 would be size 2