The number of two-level factors in the experiment.
replications
The number of replications at each combination of factor levels.
interactions
If TRUE, columns will be included representing the interactions between all the factors.
Value
A matrix where the number of rows is \(2^nk\), where \(n\) is the number of factors and \(k\)
is the number of replications. The entries are -1's and 1's.