872908.fig.003
Figure 3: Probability distribution of Δ 𝑋 . We adopt the method of nonlinear least square to estimate the exponent. S l o p e = 1 . 0 7 , S S E = 1 × 1 0 4 , 𝑅 - s q u a r e = 0 . 8 9 9 9 , and R M S E = 7 . 9 × 1 0 4 .