Use this if you are using igraph from R

add_vertices {igraph} | R Documentation |

If attributes are supplied, and they are not present in the graph,
their values for the original vertices of the graph are set to
`NA`

.

```
add_vertices(graph, nv, ..., attr = list())
```

`graph` |
The input graph. |

`nv` |
The number of vertices to add. |

`...` |
Additional arguments, they must be named, and they will be added as vertex attributes, for the newly added vertices. See also details below. |

`attr` |
A named list, its elements will be added as vertex attributes, for the newly added vertices. See also details below. |

The graph, with the vertices (and attributes) added.

Other functions for manipulating graph structure:
`+.igraph()`

,
`add_edges()`

,
`delete_edges()`

,
`delete_vertices()`

,
`edge()`

,
`igraph-minus`

,
`path()`

,
`vertex()`

```
g <- make_empty_graph() %>%
add_vertices(3, color = "red") %>%
add_vertices(2, color = "green") %>%
add_edges(c(1,2, 2,3, 3,4, 4,5))
g
V(g)[[]]
plot(g)
```

[Package *igraph* version 1.3.4 Index]