hrg_tree() creates the corresponsing igraph tree of a hierarchical
random graph model.
hrg_tree(hrg)An igraph graph with a vertex attribute called "probability".
Other hierarchical random graph functions:
consensus_tree(),
fit_hrg(),
hrg(),
hrg-methods,
predict_edges(),
print.igraphHRG(),
print.igraphHRGConsensus(),
sample_hrg()