causal_networkx.algorithms.possibly_d_sep_sets#

causal_networkx.algorithms.possibly_d_sep_sets(graph, node_x, node_y=None, max_path_length=inf)[source]#

Find all PDS sets between node_x and node_y.

Possibly d-separting (PDS) sets are adjacency paths from ‘node_x’ to some node ‘V’, which has the following characteristics for every subpath triple <X, Y, Z>:

  • Y is a collider, or

  • Y is a triangle (i.e. X, Y and Z form a complete subgraph)

If Y is a triangle, then it will be uncertain with circular edges due to the fact that it is a shielded triple, not allowing us to infer that it is a collider.

Parameters:

graph : PAG

_description_

node_x : node

The node ‘x’.

node_y : node

The node ‘y’.

max_path_length : int

The maximum length of a path to search on.

Returns:

pds_set : set

The possibly d-separating set between node_x and node_y.