graphscope.nx.generators.directed.random_k_out_graph
- graphscope.nx.generators.directed.random_k_out_graph(n, k, alpha, self_loops=True, seed=None)[source]
Returns a random k-out graph with preferential attachment.
A random k-out graph with preferential attachment is a multidigraph generated by the following algorithm.
Begin with an empty digraph, and initially set each node to have weight alpha.
Choose a node u with out-degree less than k uniformly at random.
Choose a node v from with probability proportional to its weight.
Add a directed edge from u to v, and increase the weight of v by one.
If each node has out-degree k, halt, otherwise repeat from step 2.
For more information on this model of random graph, see [1].
- Parameters
n (int) – The number of nodes in the returned graph.
k (int) – The out-degree of each node in the returned graph.
alpha (float) – A positive
float
representing the initial weight of each vertex. A higher number means that in step 3 above, nodes will be chosen more like a true uniformly random sample, and a lower number means that nodes are more likely to be chosen as their in-degree increases. If this parameter is not positive, aValueError
is raised.self_loops (bool) – If True, self-loops are allowed when generating the graph.
seed (integer, random_state, or None (default)) – Indicator of random number generation state. See Randomness.
- Returns
A k-out-regular multidigraph generated according to the above algorithm.
- Return type
MultiDiGraph
- Raises
ValueError – If alpha is not positive.
Notes
The returned multidigraph may not be strongly connected, or even weakly connected.
References
- [1]: Peterson, Nicholas R., and Boris Pittel.
“Distance between two random k-out digraphs, with and without preferential attachment.” arXiv preprint arXiv:1311.5961 (2013). <https://arxiv.org/abs/1311.5961>