R igraph manual pages

Query or set attributes of the edges in an edge sequence

Description

The $ operator is a syntactic sugar to query and set edge attributes, for edges in an edge sequence.

Usage

## S3 replacement method for class 'igraph.es'
x[[i]] <- value

## S3 replacement method for class 'igraph.es'
x[i] <- value

## S3 method for class 'igraph.es'
x$name

## S3 replacement method for class 'igraph.es'
x$name <- value

E(x, path = NULL, P = NULL, directed = NULL) <- value

Arguments

x	An edge sequence. For E<- it is a graph.
i	Index.
value	New value of the attribute, for the edges in the edge sequence.
name	Name of the edge attribute to query or set.
path	Select edges along a path, given by a vertex sequence See E.
P	Select edges via pairs of vertices. See E.
directed	Whether to use edge directions for the path or P arguments.

Details

The query form of $ is a shortcut for edge_attr, e.g. E(g)[idx]$attr is equivalent to edge_attr(g, attr, E(g)[idx]).

The assignment form of $ is a shortcut for set_edge_attr, e.g. E(g)[idx]$attr <- value is equivalent to g <- set_edge_attr(g, attr, E(g)[idx], value).

Value

A vector or list, containing the values of the attribute name for the edges in the sequence. For numeric, character or logical attributes, it is a vector of the appropriate type, otherwise it is a list.

See Also

Other vertex and edge sequences: E, V, igraph-es-indexing2, igraph-es-indexing, igraph-vs-attributes, igraph-vs-indexing2, igraph-vs-indexing, print.igraph.es, print.igraph.vs

Other vertex and edge sequences: E, V, igraph-es-indexing2, igraph-es-indexing, igraph-vs-attributes, igraph-vs-indexing2, igraph-vs-indexing, print.igraph.es, print.igraph.vs

Examples

# color edges of the largest component
largest_comp <- function(graph) {
  cl <- components(graph)
  V(graph)[which.max(cl$csize) == cl$membership]
}
g <- sample_(gnp(100, 1/100),
  with_vertex_(size = 3, label = ""),
  with_graph_(layout = layout_with_fr)
)
giant_v <- largest_comp(g)
E(g)$color <- "orange"
E(g)[giant_v %--% giant_v]$color <- "blue"
plot(g)

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