The isomorphism class is a non-negative integer number. Graphs (with the same number of vertices) having the same isomorphism class are isomorphic and isomorphic graphs always have the same isomorphism class. Currently it can handle directed graphs with 3 or 4 vertices and undirected graphs with 3 to 6 vertices.

## Arguments

- graph
The input graph.

- v
Optionally a vertex sequence. If not missing, then an induced subgraph of the input graph, consisting of this vertices, is used.

## See also

Other graph isomorphism:
`canonical_permutation()`

,
`count_isomorphisms()`

,
`count_subgraph_isomorphisms()`

,
`graph_from_isomorphism_class()`

,
`isomorphic()`

,
`isomorphisms()`

,
`subgraph_isomorphic()`

,
`subgraph_isomorphisms()`

## Examples

```
# create some non-isomorphic graphs
g1 <- graph_from_isomorphism_class(3, 10)
g2 <- graph_from_isomorphism_class(3, 11)
isomorphism_class(g1)
#> [1] 10
isomorphism_class(g2)
#> [1] 11
isomorphic(g1, g2)
#> [1] FALSE
```