Figure 4.

The set F of all fractal frames plotted in the xy-plane. The fractal frames (a, b) ∈ F are colored to distinguish those with depths D(a, b) ≥ D_max (grey) and D(a, b) <D_max (blue), thus illustrating the subsets F_d and F_s, respectively. Frames with side lengths below 20 bp are not shown to unclutter the figure.