networkx.generators.joint_degree_seq.is_valid_directed_joint_degree¶

is_valid_directed_joint_degree
(in_degrees, out_degrees, nkk)[source]¶ Checks whether the given directed joint degree input is realizable
 Parameters
in_degrees (list of integers) – in degree sequence contains the in degrees of nodes.
out_degrees (list of integers) – out degree sequence contains the out degrees of nodes.
nkk (dictionary of dictionary of integers) – directed joint degree dictionary. for nodes of out degree k (first level of dict) and nodes of in degree l (seconnd level of dict) describes the number of edges.
 Returns
returns true if given input is realizable, else returns false.
 Return type
boolean
Notes
Here is the list of conditions that the inputs (in/out degree sequences, nkk) need to satisfy for simple directed graph realizability:
Condition 0: in_degrees and out_degrees have the same length
Condition 1: nkk[k][l] is integer for all k,l
 Condition 2: sum(nkk[k])/k = number of nodes with partition id k, is an
integer and matching degree sequence
 Condition 3: number of edges and nonchords between k and l cannot exceed
maximum possible number of edges
References
 [1] B. Tillman, A. Markopoulou, C. T. Butts & M. Gjoka,
“Construction of Directed 2K Graphs”. In Proc. of KDD 2017.