# Common graphs and digraphs generators (Cython)#

AUTHORS:

• David Coudert (2012)

sage.graphs.graph_generators_pyx.RandomGNP(n, p, directed=False, loops=False, seed=None)[source]#

Return a random graph or a digraph on $$n$$ nodes.

Each edge is inserted independently with probability $$p$$.

INPUT:

• n – number of nodes of the digraph

• p – probability of an edge

• directed – boolean (default: False); whether the random graph is directed or undirected (default)

• loops – boolean (default: False); whether the random digraph may have loops or not. This value is used only when directed == True

• seed – a random.Random seed or a Python int for the random number generator (default: None)

REFERENCES:

EXAMPLES:

sage: from sage.graphs.graph_generators_pyx import RandomGNP
sage: D = RandomGNP(10, .2, directed=True, seed=0)
sage: D.num_verts()
10
sage: D.edges(sort=True, labels=False)
[(0, 2), (0, 5), (1, 5), (1, 7), (4, 1), (4, 2), (4, 9), (5, 0), (5, 2), (5, 3), (5, 7), (6, 5), (7, 1), (8, 2), (8, 6), (9, 4)]

>>> from sage.all import *
>>> from sage.graphs.graph_generators_pyx import RandomGNP
>>> D = RandomGNP(Integer(10), RealNumber('.2'), directed=True, seed=Integer(0))
>>> D.num_verts()
10
>>> D.edges(sort=True, labels=False)
[(0, 2), (0, 5), (1, 5), (1, 7), (4, 1), (4, 2), (4, 9), (5, 0), (5, 2), (5, 3), (5, 7), (6, 5), (7, 1), (8, 2), (8, 6), (9, 4)]