gRapHD (version 0.2.5)

DFS: Depth-first search

Description

Returns all vertices reachable from one specific vertex (assuming that there are no cycles).

Usage

DFS(model=NULL,edges=NULL, v, p=NULL)

Arguments

model

gRapHD object.

edges

matrix with 2 columns, each row representing one edge, and each column one of the vertices in the edge.

v

initial vertex (0<v<=p).

p

number of vertices.

Value

Vector with all vertices reachable from v, or 0 if v is an isolated vertex.

Details

Given a list of edges, and a specific vertex v, returns a vector with all vertices in the connected component containing v. The function assumes that the graph is acyclic.

References

Cormen, T.H., Leiserson, C.E., Rivest, R.L. and Stein, C. Introduction to Algorithms, 2nd Edition. MIT Press and McGraw-Hill, 2001, pp.540:9.

Examples

# NOT RUN {
set.seed(7,kind="Mersenne-Twister")
dataset <- matrix(rnorm(1000),nrow=100,ncol=10)
m <- minForest(dataset,stat="BIC")

DFS(edges=m@edges,v=1,p=10)
# [1] 5 2 9 8
#######################################################################
data(dsDiscr)
m1 <- minForest(dsDiscr,homog=TRUE,forbEdges=NULL,stat="BIC")
vertices <- DFS(edges=m1@edges, v=1, p=m1@p)

# result
vertices
# numeric(0)
# meaning that 1 is an isolated vertex

# OR
m1 <- minForest(dsDiscr,homog=TRUE,forbEdges=NULL,stat="LR")
vertices <- DFS(edges=m1@edges, v=1, p=m1@p)

# result
vertices
# [1]  4  8 12 19 18 14  7 17  5  3 10 13 15  9  6 20 16 11  2
# meaning that 1 reachs all vertices (a tree)
# }