sna (version 2.5)

symmetrize: Symmetrize an Adjacency Matrix

Description

Symmetrizes the elements of mats according to the rule in rule.

Usage

symmetrize(mats, rule="weak", return.as.edgelist=FALSE)

Arguments

mats

a graph or graph stack.

rule

one of ``upper'', ``lower'', ``strong'' or ``weak''.

return.as.edgelist

logical; should the symmetrized graphs be returned in edgelist form?

Value

The symmetrized graph stack

Details

The rules used by symmetrize are as follows:

1. upper: Copy the upper triangle over the lower triangle

2. lower: Copy the lower triangle over the upper triangle

3. strong: i<->j iff i->j and i<-j (AND rule)

4. weak: i<->j iff i->j or i<-j (OR rule)

References

Wasserman, S., and Faust, K. (1994). Social Network Analysis: Methods and Applications. Cambridge: Cambridge University Press.

Examples

# NOT RUN {
#Generate a graph
g<-rgraph(5)

#Weak symmetrization
symmetrize(g)

#Strong symmetrization
symmetrize(g,rule="strong")
# }