Frontdoor

class pgmpy.identification.frontdoor.Frontdoor(variant=None)

Bases: _BaseIdentification

Given a causal graph, finds the set of variables satisfying frontdoor criterion.

Given a causal graph with exposures and outcomes roles specified, the FrontdoorIdentification class provides methods to find the set of variables satisfying the frontdoor criterion with respect to exposures and outcomes in the causal graph.

Parameters:

variant: all | None

If all, returns all possible frontdoor identification causal graphs. If None, returns one at random.

Examples

>>> from pgmpy.base import DAG
>>> dag = DAG(
...     ebunch=[
...         ("X", "M"),
...         ("M", "Y"),
...         ("U", "X"),
...         ("U", "Y"),
...     ],
...     roles={"exposures": "X", "outcomes": "Y"},
... )
>>> dag_with_adj, is_identified = Frontdoor().identify(dag)
>>> dag_with_adj.get_role_dict()
{'exposures': ['X'], 'outcomes': ['Y'], 'frontdoor': ['M']}
>>> Frontdoor().validate(dag_with_adj)
True