Fig. 4

Histogram of communities grouped by the average internal and outbound edges per member. The numbers of bins in the x and y axes are 200 and 400, respectively. The counting in each bin is normalized by dividing the count by the total number of communities and the bin area. The bin area of the right panel is two times the left panel. To make the normalized values comparable to those in Fig. 6, we set the bin area of the left panel to 1. The normalized counting in each bin is given by the color, as defined by the color bar. More than 99% of the detected communities have \(k_{\text {\tiny C}}^{\text {out}} > k_{\text {\tiny C}}^{\text {int}}\), and \(k_{\text {\tiny C}}^{\text {out}}\) is usually much greater than \(k_{\text {\tiny C}}^{\text {int}}\)