Stellar number density distribution for a few area cells of the data sample with 2 < M_G ≤ 3. Each panel is labelled by the area cell’s mid-point (X, Y) coordinates. The function obtained by GP regression is shown in solid black; the fitted symmetric function ($\widehat{n}$) of Eq. (5) is shown in dashed red; the raw number count (N) with its associated Poisson noise uncertainty is shown as a 1σ band.