graphical_models.classes.mags.ancestral_graph.AncestralGraph.legitimate_mark_changes

AncestralGraph.legitimate_mark_changes(verbose=False, strict=True)

Return directed edges that can be changed to bidirected edges, and bidirected edges that can be changed to directed edges.

Parameters

• verbose – If True, print each possible mark change and which condition it fails, if any.

• strict – If True, check discriminating path condition. Otherwise, check only equality of parents and spouses.

Returns

Directed edges that can be changed to bidirected edges, and bidirected edges that can be changed to directed edges (which will be the new directed edge).

Return type

(mark_changes_dir, mark_changes_bidir)

Example

>>> from graphical_models import AncestralGraph
>>> g = AncestralGraph(directed={(0, 1)}, bidirected={(1, 2)})
>>> g.legitimate_mark_changes()
({(0, 1)}, {(2, 1)})