Figure 2
From: Inherent directionality explains the lack of feedback loops in empirical networks
Fraction of feedback loops, F(k), as a function of the loop length, k, in empirical networks.
Black squares correspond to empirical data and red dashed lines stand for fits of the empirical data to an asymptotic exponential curve (fit done using data for k > 4). Pale blue pentagons stand for configurational randomizations and pale pink diamonds for directionality randomizations. Blue crosses mark the best fit of our probabilistic model (the parameter γ has been fitted using a least-squares method to log F(k) versus k). The resulting optimal γ values for the different networks are compiled in Table 1. Blue dashed lines correspond to the asymptotic analytical estimate of Eq.(4) for the corresponding γ. Notice the closeness between the exponential fit to empirical data and the analytical prediction.
