grash-operations {gRain}R Documentation

Operations on undirected and directed acyclic graphs.

Description

Make operations on undirected and directed acyclic graphs.

Usage

moralize(dag)
mcs(ug,amat=as.adjmat(ug), vn=colnames(amat), root=NULL, index=FALSE)
triangulate(ug,method="standard", nLevels, matrix=FALSE)
ripOrder(ug,root=NULL,nLevels=NULL)
jTree(ug, method="standard", vn=nodes(ug),nLevels, control=list())

Arguments

dag A directed graph (of class "dagsh")
ug An undirected graph (of class "ugsh")
method The triangulation method, "standard" is a C implementation of a minimum clique weight heuristic, "mcwh" is a Fortran implementation of the same (kindly provided by Peter Green) and "R" is a corresponding R implementation.
matrix Should the triangulated graph be returned as an adjacency matrix
amat The graph represented as an adjancecy matrix
vn The node names as they appear in the adjancecy matrix
root Variables which must be in the first clique in the rip-ordering
nLevels Number of levels of the nodes in the graph
index If TRUE, then a permutation is returned
control Currently not used
... Currently not used.

Details

The jTree (for "junction tree") is just a wrapper for a call of triangulate followed by a call of ripOrder.

Value

moralize and triangulate returns objects of class "graphsh".
mcs returns a vector or NULL.
ripOrder returns a list with cliques, separators etc.

Author(s)

Søren Højsgaard, sorenh@agrsci.dk

See Also

newugsh, newug, newdagsh, newdag

Examples


## Undirected graphs
##
ug <- newug(~me+ve,~me+al,~ve+al,~al+an,~al+st,~an+st)
edges(ug)
nodes(ug)
mcs(ug)
ripOrder(ug)

## Directed graphs
##
dag <- newdag(~me+ve,~me+al,~ve+al,~al+an,~al+st,~an+st)
edges(dag)
nodes(dag)
moralize(dag)

[Package gRain version 0.3.4 Index]