msep function

The m-separation criterion

msep determines whether two set of nodes are m-separated by a third set of nodes.

msep(a, alpha, beta, C = c())

Arguments

• a: An adjacency matrix, or a graph that can be a graphNEL or an igraph object or a vector of length $3e$, where $e$ is the number of edges of the graph, that is a sequence of triples (type, node1label, node2label). The type of edge can be "a" (arrows from node1 to node2), "b" (arcs), and "l" (lines).
• alpha: A subset of the node set of a
• beta: Another disjoint subset of the node set of a
• C: A third disjoint subset of the node set of a

Returns

A logical value. TRUE if alpha and beta are m-separated given C. FALSE otherwise.

References

Richardson, T.S. and Spirtes, P. (2002) Ancestral graph Markov models. Annals of Statistics, 30(4), 962-1030.

Sadeghi, K. and Lauritzen, S.L. (2014). Markov properties for loopless mixed graphs. Bernoulli 20(2), 676-696.

Author(s)

Kayvan Sadeghi

See Also

dSep, MarkEqMag

Examples

H <-matrix(c(0,0,0,0,
                 1,0,0,1,
                 0,1,0,0,
                 0,0,0,0),4,4)
msep(H,1,4, 2)
msep(H,1,4, c())