An edge sequence is a vector containing numeric edge ids, with a special
class attribute that allows custom operations: selecting subsets of
edges based on attributes, or graph structure, creating the
intersection, union of edges, etc.
Usage
E(graph, P = NULL, path = NULL, directed = TRUE)
Value
An edge sequence of the graph.
Arguments
graph
The graph.
P
A list of vertices to select edges via pairs of vertices.
The first and second vertices select the first edge, the third
and fourth the second, etc.
path
A list of vertices, to select edges along a path.
Note that this only works reliable for simple graphs. If the graph
has multiple edges, one of them will be chosen arbitrarily to
be included in the edge sequence.
directed
Whether to consider edge directions in the P
argument, for directed graphs.
Indexing edge sequences
Edge sequences mostly behave like regular vectors, but there are some
additional indexing operations that are specific for them;
e.g. selecting edges based on graph structure, or based on edge
attributes. See [.igraph.es for details.
Querying or setting attributes
Edge sequences can be used to query or set attributes for the
edges in the sequence. See $.igraph.es for details.
Details
Edge sequences are usually used as igraph function arguments that
refer to edges of a graph.
An edge sequence is tied to the graph it refers to: it really denoted
the specific edges of that graph, and cannot be used together with
another graph.
An edge sequence is most often created by the E() function. The
result includes edges in increasing edge id order by default (if. none
of the P and path arguments are used). An edge
sequence can be indexed by a numeric vector, just like a regular R
vector. See links to other edge sequence operations below.
See Also
Other vertex and edge sequences:
V(),
igraph-es-attributes,
igraph-es-indexing2,
igraph-es-indexing,
igraph-vs-attributes,
igraph-vs-indexing2,
igraph-vs-indexing,
print.igraph.es(),
print.igraph.vs()
# Edges of an unnamed graphg <- make_ring(10)
E(g)
# Edges of a named graphg2 <- make_ring(10) %>%
set_vertex_attr("name", value = letters[1:10])
E(g2)