Top: median value of the OPCF at each distance for 10 realisations of a fractal distribution with D = 1.6 in red. Black solid lines represent the quartiles Q₁ and Q₃, with the inter-quartile range area shaded in blue. The horizontal dashed black line at constant value 1 represents the theoretical value for CSR, and the vertical dashed green line shows the average value of the ϵ obtained by S2D2 (see Table 2). Middle: same for a fractal distribution with D = 2.0. Bottom: same for a fractal distribution with D = 2.6.