is.isolate {sna} | R Documentation

## Is Ego an Isolate?

### Description

Returns TRUE iff ego is an isolate in graph `g` of `dat`.

### Usage

    is.isolate(dat, ego, g=1, diag=FALSE)

### Arguments

`dat` | one or more input graphs.
`ego` | index of the vertex (or a vector of vertices) to check.
`g` | which graph should be examined?
`diag` | boolean indicating whether adjacency matrix diagonals (i.e., loops) contain meaningful data.

### Details

In the valued case, any non-zero edge value is taken as sufficient to establish a tie.

### Value

A boolean value (or vector thereof) indicating isolate status

### Author(s)

Carter T. Butts buttsc@uci.edu

### References

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

West, D.B. (1996). Introduction to Graph Theory. Upper Saddle River, NJ: Prentice Hall.

### See Also

`isolates`, `add.isolates`

### Examples

    #Generate a test graph
    g<-rgraph(20)
    g[,4]<-0          #Create an isolate
    g[4,]<-0

    #Check for isolates
    is.isolate(g,2)  #2 is almost surely not an isolate
    is.isolate(g,4)  #4 is, by construction

[Package sna version 1.1 Index]