design_scan()
1 1 1 1 1 1 -1 -1 1 -1 1 -1
coef_scan()
1 -1 -1 1
a1_matrix(design,ncol=3)
abc_solve(a1,coef)
abc

design_scan()
1 1 1 1 1 -1 1 -1 1
coef_scan()
1 -1 -1
a1_matrix(design,ncol=3)
abc_solve(a1,coef)
abc