Drawing a factor graph - invisible when edge weight is None

[tillwenke]

Subject of the issue

G = FactorGraph()

G.add_nodes_from(['a', 'b', 'c'])

phi1 = DiscreteFactor(['a', 'b'], [2, 2], np.random.rand(4))

G.add_nodes_from([phi1])

G.add_edge('a', phi1)

nx.draw(Fg)
plt.show()

the graph is not drawn

when G.add_edge('a', phi1, weight=0)

it gets drawn.

Your environment

• 0.1.25
• 3.10

Expected behaviour

The graph should be drawable without explicitly setting a weight.

[ankurankan]

@tillwenke This seems to stemming from the recent release of networkx where the default weight value of edges seem to have been changed. I think a potential quick fix in our code could be to by default add weight=0 argument when calling networkx's add_edge method.