Figure 1.

Gradient and spiral array construction. We depict 3×3 constructions using individuals ${\mathcal{I}}_{(1)},{\mathcal{I}}_{(2)},\dots ,{\mathcal{I}}_{(9)}$ corresponding to p₍₁₎ ≤ p₍₂₎ ≤ ⋯ ≤ p₍₉₎. Constructing K × K arrays for other values of K is done similarly.