Fig. 11
The Pearson correlation matrix for accessibility indicators: cumulative indicators \(S^{(H)}\) and threshold indicators \(\tau {(xk)}\). Geographical indicators are the average degrees of the access graph at different time points: \(t_c=\{30, 45, 60\}\) minutes and \(t_c=\{\frac{1}{3}, \frac{1}{2}, \frac{2}{3}\}t_{max}\). \(\langle k\rangle _{30}\) is the average degree at \(t_c=30\) min, and \(\langle k\rangle _{t_{max}/3}\) is the average degree at \(t_c=\frac{1}{3}t_{max}\) (and similarly for others). Blue and red shades represent positive and negative correlations, respectively.
