Filling factor functions of the model L512: total filling factors of clusters and voids, ℱ_tot, and filling factors of maximal clusters and voids, ℱ_max, as functions of threshold density, D_t, plotted in logarithmic scales. Solid lines indicate total filling factors of high- and low-density regions, dashed lines indicate maximal clusters and voids, blue indicates clusters, and black indicates voids. Functions are calculated using smoothing kernels 2 and 8 h⁻¹ Mpc (left and right panels). Bottom row: the same functions for observed SDSS samples.