Source code for networkx.generators.stochastic

"""Stocastic graph."""
import networkx as nx
#    Copyright (C) 2010 by 
#    Aric Hagberg <>
#    Dan Schult <>
#    Pieter Swart <>
#    All rights reserved.
#    BSD license.
__author__ = "Aric Hagberg <>"
__all__ = ['stochastic_graph']

[docs]def stochastic_graph(G, copy=True, weight='weight'): """Return a right-stochastic representation of G. A right-stochastic graph is a weighted graph in which all of the node (out) neighbors edge weights sum to 1. Parameters ----------- G : graph A NetworkX graph, must have valid edge weights copy : boolean, optional If True make a copy of the graph, otherwise modify original graph weight : key (optional) Edge data key used for weight. If None all weights are set to 1. """ if type(G) == nx.MultiGraph or type(G) == nx.MultiDiGraph: raise Exception("stochastic_graph not implemented for multigraphs") if not G.is_directed(): raise Exception("stochastic_graph not defined for undirected graphs") if copy: W=nx.DiGraph(G) else: W=G # reference original graph, no copy degree=W.out_degree(weight=weight) for (u,v,d) in W.edges(data=True): d[weight]=d.get(weight,1.0)/degree[u] return W