L_ratio and N_peaks statistics shown as a function of the large scale overdensity δ_LSS at redshift z = 4.0. The input spectrum is the Neufeld solution. The colormap in the upper panel shows the underlying PDF normalized at a given δ_LSS. Overdense regions overall decrease L_ratio. At a higher overdensity, this trend halts as the ratio becomes more fluctuating for different LOS. For the peak fractions, we find a gradual decrease of double peaks. This is caused by absorption features on the blue side of the line-center. Thus, the decrease of double peaks is strongly correlated with the increase of the fraction of single peaked spectra.