Distributions of the vertical density of the grid points for different grids. The regular grid (black) was taken at half resolution, meaning every second grid point. The different irregular grids (blue, cyan, and yellow) were sampled by the quantity indicated in the legend and had three million sites. The shaded histograms (red) show the τ = 1 heights at the line core and the wing at −27 km s⁻¹ from the core.