Each columns item will have E-1 time-lagged vectors created.
The column name is appended with (t-n). For example, data
columns X, Y, with E = 2 will have columns named
X(t-0) X(t-1) Y(t-0) Y(t-1).
The returned data.frame does not have a time column.
If deletePartial is TRUE, the returned
data.frame is truncated by tau * (E-1) rows to remove state vectors
with partial data (NaN elements).