# symmetrize: Symmetrize an Adjacency Matrix In sna: Tools for Social Network Analysis

## Description

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

## Usage

 1 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?

## 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)

## Value

The symmetrized graph stack

## Author(s)

Carter T. Butts [email protected]

## References

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

## Examples

 1 2 3 4 5 6 7 8 #Generate a graph g<-rgraph(5) #Weak symmetrization symmetrize(g) #Strong symmetrization symmetrize(g,rule="strong")

### Example output

network: Classes for Relational Data
Version 1.13.0 created on 2015-08-31.
copyright (c) 2005, Carter T. Butts, University of California-Irvine
Mark S. Handcock, University of California -- Los Angeles
David R. Hunter, Penn State University
Martina Morris, University of Washington
Skye Bender-deMoll, University of Washington
For citation information, type citation("network").
Type help("network-package") to get started.

sna: Tools for Social Network Analysis
Version 2.4 created on 2016-07-23.
copyright (c) 2005, Carter T. Butts, University of California-Irvine
For citation information, type citation("sna").
Type help(package="sna") to get started.

[,1] [,2] [,3] [,4] [,5]
[1,]    0    1    0    1    0
[2,]    1    0    1    1    1
[3,]    0    1    0    1    0
[4,]    1    1    1    0    0
[5,]    0    1    0    0    0
[,1] [,2] [,3] [,4] [,5]
[1,]    0    1    0    0    0
[2,]    1    0    0    0    0
[3,]    0    0    0    0    0
[4,]    0    0    0    0    0
[5,]    0    0    0    0    0

sna documentation built on May 30, 2017, 12:18 a.m.