Simple Graph Operations {ggm} | R Documentation |
Finds the boundary, children, parents of a subset of nodes of a graph.
bd(nn, A) ch(nn, A) pa(nn, A)
nn |
a vector of nodes. It may either a numeric vector, or a
character vector. If it is character vector must be a subset
of the rownames of the edge matrix. |
A |
a square matrix specifying the edge matrix of the graph |
For the definitions of these operators see Lauritzen (1996).
A vector, specifying the boundary or the children or the parents of nodes nn
in the graph. This is a numeric or a character vector depending
on the mode of nn
.
Giovanni M. Marchetti
Lauritzen, S. (1996). Graphical models. Oxford: Clarendon Press.
## find boundary of a subset of nodes of a DAG G <- DAG(y ~ x+b+a, b~a, x~a) bd("b", G) bd(c("b", "x"), G) bd(2, G) bd(c(2,3), G) ## find boundary of a subset of nodes of an UG G <- UG(~ y*x*z + z*h*v) bd("z", G) bd(c("y", "x"), G) bd(5, G) bd(c(2,5), G) ## children of a subset of nodes of a DAG G <- DAG(y ~ x+b+a, b~a, x~a) ch("b", G) ch(c("b", "x"), G) ch(2, G) ch(c(2,3), G) ## parents of a subset of nodes of a DAG pa("b", G) pa(c("b", "x"), G) pa(2, G) pa(c(2,3), G)