Use this if you are using igraph from R
| vertex_attr<- {igraph} | R Documentation | 
Set one or more vertex attributes
vertex_attr(graph, name, index = V(graph)) <- value
graph | 
 The graph.  | 
name | 
 The name of the vertex attribute to set. If missing,
then   | 
index | 
 An optional vertex sequence to set the attributes of a subset of vertices.  | 
value | 
 The new value of the attribute(s) for all
(or   | 
The graph, with the vertex attribute(s) added or set.
Other graph attributes: 
delete_edge_attr(),
delete_graph_attr(),
delete_vertex_attr(),
edge_attr<-(),
edge_attr_names(),
edge_attr(),
graph_attr<-(),
graph_attr_names(),
graph_attr(),
igraph-dollar,
igraph-vs-attributes,
set_edge_attr(),
set_graph_attr(),
set_vertex_attr(),
vertex_attr_names(),
vertex_attr()
g <- make_ring(10)
vertex_attr(g) <- list(name = LETTERS[1:10],
                        color = rep("yellow", gorder(g)))
vertex_attr(g, "label") <- V(g)$name
g
plot(g)