Define a full factorial design matrix.
Design = fullfact(levels)
row vector with number of levels for each factor
full factorial design matrix
optional Flag=%T (default) will use [-1 1] or [-1 0 1] as levels for 2 or 3 level factors (otherwise [1 2] and [1 2 3] is used).
Returns a full factorial design matrix where number of levels for each factor is given by the respective values in levels.
http://www.statsoft.com/textbook/experimental-design