Find all Unshielded Triples in an Undirected Graph
Find all unshielded triples in an undirected graph, q, i.e., the ordered ((x,y,z) with x < z) list of all the triples in the graph.
find.unsh.triple(g, check=TRUE)
g |
adjacency matrix of type amat.cpdag representing the
skeleton; since a skeleton consists only of undirected edges,
|
check |
logical indicating that the symmetry of |
A triple of nodes x, y and z is
“unshielded”, if (all of these are true):
x and y are connected;
y and z are connected;
x and z are not connected.
unshTripl |
Matrix with 3 rows containing in each column an unshielded triple |
unshVect |
Vector containing the unique number for each column in unshTripl (for internal use only) |
Diego Colombo, Markus Kalisch (kalisch@stat.math.ethz.ch), and Martin Maechler
data(gmG)
if (require(Rgraphviz)) {
## show graph
plot(gmG$g, main = "True DAG")
}
## prepare skeleton use in example
g <- wgtMatrix(gmG$g) ## compute weight matrix
g <- 1*(g != 0) # wgts --> 0/1; still lower triangular
print.table(g, zero.print=".")
skel <- g + t(g) ## adjacency matrix of skeleton
## estimate unshielded triples -- there are 13 :
(uTr <- find.unsh.triple(skel))Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.