Fig. 2
From: Estimation of diffusion constants from single molecular measurement without explicit tracking
Mean square displacement to the nearest particle. A comparison of MSDN and MSD. The black straight line corresponds to the expected MSD, while the black curve is the expected MSDN, with D=1 μm2/s and ρ=1 particles/μm2. The points are the mean MSDN directly calculated from corresponding simulated data. The error bars indicate the standard deviation from one thousand independent simulations. The red line indicates the asymptotic value of the expected MSDN at Δt → ∞