Classify dyads in a directed graphs. The relationship between each pair of vertices is measured. It can be in three states: mutual, asymmetric or non-existent.

## Value

A named numeric vector with three elements:

- mut
The number of pairs with mutual connections.

- asym
The number of pairs with non-mutual connections.

- null
The number of pairs with no connection between them.

## References

Holland, P.W. and Leinhardt, S. A Method for Detecting Structure
in Sociometric Data. *American Journal of Sociology*, 76, 492--513.
1970.

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

## See also

`triad_census()`

for the same classification, but with
triples.

Other graph motifs:
`count_motifs()`

,
`motifs()`

,
`sample_motifs()`

## Author

Gabor Csardi csardi.gabor@gmail.com

## Examples

```
g <- sample_pa(100)
dyad_census(g)
#> $mut
#> [1] 0
#>
#> $asym
#> [1] 99
#>
#> $null
#> [1] 4851
#>
```