
Overview of graph indices 

Path length  Mean of the nodes’ shortest paths 
Clustering coefficient  Mean of the nodes’ triangles intensity around each node 
Diameter  Maximum graph eccentricity 
Causal density  Sum of all significant couplings in 
Spectral radius  : first eigenvalue of adjacency matrix 
Spectral gap  : the difference between the first two eigenvalues of matrix 
Algebraic connectivity  : the second smallest eigenvalue of the Laplacian matrix 
