This is a helper function that simplifies adding and deleting vertices to/from graphs.
vertex(...)
vertices(...)A special object that can be used with together with igraph graphs and the plus and minus operators.
vertices() is an alias for vertex().
When adding vertices via +, all unnamed arguments are interpreted
as vertex names of the new vertices. Named arguments are interpreted as
vertex attributes for the new vertices.
When deleting vertices via -, all arguments of vertex() (or
vertices()) are concatenated via c() and passed to
delete_vertices().
Other functions for manipulating graph structure:
+.igraph(),
add_edges(),
add_vertices(),
complementer(),
compose(),
connect(),
contract(),
delete_edges(),
delete_vertices(),
difference(),
difference.igraph(),
disjoint_union(),
edge(),
igraph-minus,
intersection(),
intersection.igraph(),
path(),
permute(),
rep.igraph(),
reverse_edges(),
simplify(),
union(),
union.igraph()
g <- make_(ring(10), with_vertex_(name = LETTERS[1:10])) +
vertices("X", "Y")
g
#> IGRAPH 7e6a648 UN-- 12 10 -- Ring graph
#> + attr: name (g/c), mutual (g/l), circular (g/l), name (v/c)
#> + edges from 7e6a648 (vertex names):
#> [1] A--B B--C C--D D--E E--F F--G G--H H--I I--J A--J
plot(g)