A balanced 1-spread of PG(3,2) obtained via cyclic construction
data(spreadn4t2a)The spread is formatted as a 3-dimensional array, where the [i,j,k]-th element indicates whether or not the ith basic factor is present in the jth effect of the kth flat of the spread.
The spread consists of five subspaces \(f_1, f_2, f_3, f_4, f_5\) given by \(f_1=(D,BC,BCD)\), \(f_2 = (C,AB, ABC)\), \(f_3 = (B,ACD, ABCD)\), \(f_4 = (A,BD, ABD)\) and \(f_5=(CD,AC,AD)\).
Spencer, N.A., Ranjan, P., and Mendivil, F., (2019), "Isomorphism Check for \(2^n\) Factorial Designs with Randomization Restrictions", Journal of Statistical Theory and Practice, 13(60),1-24 [https://doi.org/10.1007/s42519-019-0064-5]
checkSpreadIsomorphism for checking the isomorphism of balanced spreads.
checkStarIsomorphism for checking the isomorphism of balanced covering stars.