gtrans {sna} | R Documentation

## Compute the Transitivity of an Input Graph or Graph Stack

### Description

`gtrans` returns the transitivity of the elements of `dat` selected by `g`, using the definition of `measure`. Triads involving missing values are omitted from the analysis.

### Usage

    gtrans(dat, g=NULL, diag=FALSE, mode="digraph", measure = c("weak",
        "strong", "weakcensus", "strongcensus"))

### Arguments

`dat` | a collection of input graphs.
`g` | a vector indicating the graphs which are to be analyzed; by default, all graphs are analyzed.
`diag` | a boolean indicating whether or not diagonal entries (loops) are to be taken as valid data.
`mode` | `"digraph"` if directed triads are sought, or else `"graph"`.
`measure` | one of `"weak"` (default), `"strong"`, `"weakcensus"`, or `"strongcensus"`.

### Details

Transitivity is a triadic, algebraic structural constraint. In its weak form, the transitive constraint corresponds to a->b->c => a->c. In the corresponding strong form, the constraint is a->b->c <=> a->c. (Note that the weak form is that most commonly employed.) Where `measure=="weak"`, the fraction of potentially intransitive triads obeying the weak condition is returned. With the `measure=="weakcensus"` setting, by contrast, the total number of transitive triads is computed. The `strong` versions of the measures are similar to the above, save in that the set of all triads is considered (since all are ``at risk'' for intransitivity).

### Value

A vector of transitivity scores

### Author(s)

Carter T. Butts buttsc@uci.edu

### References

Holland, P.W., and Leinhardt, S. (1972). ``Some Evidence on the Transitivity of Positive Interpersonal Sentiment.'' American Journal of Sociology, 72, 1205-1209.

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

### See Also

`triad.classify`, `cugtest`

### Examples

    #Draw some random graphs
    g<-rgraph(5,10)

    #Find transitivity scores
    gtrans(g)

[Package sna version 1.1 Index]