causaldag.classes.ancestral_graph.AncestralGraph.add_undirected

AncestralGraph.add_undirected(i: Hashable, j: Hashable)

Add an undirected edge between nodes i and j.

Parameters:

• i – first endpoint of undirected edge.
• j – second endpoint of undirected edge.

Examples

>>> import causaldag as cd
>>> g = cd.AncestralGraph()
>>> g.add_undirected(1, 2)
>>> g.undirected
{frozenset({i, j})}