A balanced 2-spread of PG(5,2) obtained via cyclic construction
data(spreadn6t3a)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 9 subspaces \(f_1, f_2, ..., f_9\) each of size 7. The subspaces are \(f_1=(A,EF,AEF,BCE,ABCE,BCF,ABCF)\), \(f_2 = (B,AF,ABF,CDF,BCDF,ACD,ABCD)\), \(f_3 = (C,AB,ABC,ADE,ACDE,BDE,BCDE)\), \(f_4 = (D,BC,BCD,BEF,BDEF,CEF,CDEF)\), \(f_5=(E,CD,CDE,ACF,ACEF,ADF,ADEF)\), \(f_6=(F,DE,DEF,ABD,ABDF,ABE,ABEF)\), \(f_7=(BD,BF,DF,ACE,ABCDE,ABCEF,ACDEF)\), \(f_8=(AC,CE,AE,BDF,ABCDF,BCDEF,ABDEF)\) and \(f_9=(AD,BE,ABDE,CF,ACDF,BCEF,ABCDEF)\).
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.