perfSets: Finds a perfect sequence

In gRapHD: Efficient Selection of Undirected Graphical Models for High-Dimensional Datasets

Description

Finds a perfect sequence, returning the cliques, histories, residuals, and separators of a given triangulated graph.

Usage

perfSets(model=NULL,edges=NULL,p=NULL,varType=0,from=0)

Arguments

model	gRapHD object.
edges	matrix with 2 columns, each row representing one edge, and each column one of the vertices in the edge.
p	number of vertices.
varType	vector indicating the type of each variable: 0 if continuous, or 1 if discrete.
from	initial vertex to be used in MCS.

Details

Based on the perfect numbering of mcs, returns the perfect sequnece.
The sequence is given by the cliques in the graph: Cj=closure(α(j)) intersection {α(1),...,α(j)}, j>=1.
The other sets are given by:
- Histories: Hj=C1 union ... union Cj
- Residuals: Rj=Cj \ H(j-1)
- Separators: Sj=H(j-1) intersection Cj

Value

A list containing:

cliques	list.
histories	list.
residuals	list.
separators	list.

Author(s)

Gabriel Coelho Goncalves de Abreu ([e-mail])

References

Lauritzen, S.L. (1996) Graphical Models, Oxford University Press.

Examples

edges <- matrix(c(1,2,2,3,2,4,2,5,2,6,3,4,4,5,5,6),ncol=2,byrow=TRUE)
setList <- perfSets(edges=edges, p=6, varType=0, from=1)
#    > str(setList)
#    List of 4
#     $ cliques   :List of 4
#      ..$ : int [1:2] 1 2
#      ..$ : int [1:3] 2 3 4
#      ..$ : int [1:3] 2 4 5
#      ..$ : int [1:3] 2 5 6
#     $ histories :List of 4
#      ..$ : int [1:2] 1 2
#      ..$ : int [1:4] 1 2 3 4
#      ..$ : int [1:5] 1 2 3 4 5
#      ..$ : int [1:6] 1 2 3 4 5 6
#     $ separators:List of 4
#      ..$ : NULL
#      ..$ : int 2
#      ..$ : int [1:2] 2 4
#      ..$ : int [1:2] 2 5
#     $ residuals :List of 4
#      ..$ : int [1:2] 1 2
#      ..$ : int [1:2] 3 4
#      ..$ : int 5
#      ..$ : int 6

gRapHD documentation built on Feb. 9, 2018, 6:05 a.m.