Query or set attributes of the vertices in a vertex sequence
Source:R/iterators.R
igraph-vs-attributes.Rd
The $
operator is a syntactic sugar to query and set the
attributes of the vertices in a vertex sequence.
Usage
# S3 method for igraph.vs
[[(x, i) <- value
# S3 method for igraph.vs
[(x, i) <- value
# S3 method for igraph.vs
$(x, name)
# S3 method for igraph.vs
$(x, name) <- value
V(x) <- value
Arguments
- x
A vertex sequence. For
V<-
it is a graph.- i
Index.
- value
New value of the attribute, for the vertices in the vertex sequence.
- name
Name of the vertex attribute to query or set.
Value
A vector or list, containing the values of
attribute name
for the vertices in the vertex sequence.
For numeric, character or logical attributes, it is a vector of the
appropriate type, otherwise it is a list.
Details
The query form of $
is a shortcut for
vertex_attr()
, e.g. V(g)[idx]$attr
is equivalent
to vertex_attr(g, attr, V(g)[idx])
.
The assignment form of $
is a shortcut for
set_vertex_attr()
, e.g. V(g)[idx]$attr <- value
is
equivalent to g <- set_vertex_attr(g, attr, V(g)[idx], value)
.
See also
Other vertex and edge sequences:
E()
,
V()
,
as_ids()
,
igraph-es-attributes
,
igraph-es-indexing
,
igraph-es-indexing2
,
igraph-vs-indexing
,
igraph-vs-indexing2
,
print.igraph.es()
,
print.igraph.vs()
Vertex, edge and graph attributes
delete_edge_attr()
,
delete_graph_attr()
,
delete_vertex_attr()
,
edge_attr()
,
edge_attr<-()
,
edge_attr_names()
,
graph_attr()
,
graph_attr<-()
,
graph_attr_names()
,
igraph-attribute-combination
,
igraph-dollar
,
set_edge_attr()
,
set_graph_attr()
,
set_vertex_attr()
,
vertex_attr()
,
vertex_attr<-()
,
vertex_attr_names()
Examples
g <- make_(
ring(10),
with_vertex_(
name = LETTERS[1:10],
color = sample(1:2, 10, replace = TRUE)
)
)
V(g)$name
#> [1] "A" "B" "C" "D" "E" "F" "G" "H" "I" "J"
V(g)$color
#> [1] 1 1 1 1 2 1 2 2 2 2
V(g)$frame.color <- V(g)$color
# color vertices of the largest component
largest_comp <- function(graph) {
cl <- components(graph)
V(graph)[which.max(cl$csize) == cl$membership]
}
g <- sample_(
gnp(100, 2 / 100),
with_vertex_(size = 3, label = ""),
with_graph_(layout = layout_with_fr)
)
giant_v <- largest_comp(g)
V(g)$color <- "blue"
V(g)[giant_v]$color <- "orange"
plot(g)