ggm (version 2.5.1)

Max: Maximisation for graphs

Description

Max generates a maximal graph that induces the same independence model from a non-maximal graph.

Usage

Max(amat)

Value

A matrix that consists 4 different integers as an \(ij\)-element: 0 for a missing edge between \(i\) and \(j\), 1 for an arrow from \(i\) to \(j\), 10 for a full line between \(i\) and \(j\), and 100 for a bi-directed arrow between \(i\) and \(j\). These numbers are added to be associated with multiple edges of different types. The matrix is symmetric w.r.t full lines and bi-directed arrows.

Arguments

amat

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).

Author

Kayvan Sadeghi

Details

Max looks for non-adjacent pais of nodes that are connected by primitive inducing paths, and connect such pairs by an appropriate edge.

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.

See Also

MAG, MRG, msep, MSG

Examples

H <- matrix(c(  0,100,  1,  0,
	          100,  0,100,  0,
	            0,100,  0,100,
	            0,  1,100,  0), 4, 4)
Max(H)