Fig. 2: Quantile–quantile plots of VLP area extracted from the AFM images verses a theoretical Gaussian distribution show that the thermally aged particles are not normally distributed.
From: Analyzing atomic force microscopy images of virus-like particles by expectation-maximization

Plots are shown for samples following 2 h (A), 3 h (B) and 4 h (C) of thermal aging. That the Q–Q plots are not linear indicates significant deviation from a single Gaussian accurately describing the VLP distribution. The included red line represents the perfect, noiseless, data, and model.