RepMarDAG determines whether a given maximal ancestral graph can
be Markov equivalent to a directed acyclic graph, and if that is the case,
it finds a directed acyclic graph that is Markov equivalent to the given
graph.
RepMarDAG(amat)A list with two components: verify and
amat. verify is a logical value, TRUE if there is
a representational Markov equivalence and FALSE otherwise.
amat is either NA if verify == FALSE or
the adjacency matrix of the generated graph, if
verify == TRUE. In this case it consists of 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.
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).
Kayvan Sadeghi
RepMarDAG first looks whether the subgraph induced by full lines
is chordal and whether there is a minimal collider path or cycle of
length 4 in graph.
Sadeghi, K. (2011). Markov equivalences for subclasses of loopless mixed graphs. Submitted, 2011.
MarkEqMag, MarkEqRcg, RepMarBG,
RepMarUG
H<-matrix(c(0,10,0,0,10,0,0,0,0,1,0,100,0,0,100,0),4,4)
RepMarBG(H)
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