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())

Arguments

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.

Value

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

Examples

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
#> IGRAPH 2d741bb D--- 5 4 -- 
#> + attr: color (v/c)
#> + edges from 2d741bb:
#> [1] 1->2 2->3 3->4 4->5
V(g)[[]]
#> + 5/5 vertices, from 2d741bb:
#>   color
#> 1   red
#> 2   red
#> 3   red
#> 4 green
#> 5 green
plot(g)