Create an igraph graph from a list of edges, or a notable graph

graph() was renamed to make_graph() to create a more consistent API.

graph(
  edges,
  ...,
  n = max(edges),
  isolates = NULL,
  directed = TRUE,
  dir = directed,
  simplify = TRUE
)

Arguments

edges

A vector defining the edges, the first edge points from the first element to the second, the second edge from the third to the fourth, etc. For a numeric vector, these are interpreted as internal vertex ids. For character vectors, they are interpreted as vertex names.

Alternatively, this can be a character scalar, the name of a notable graph. See Notable graphs below. The name is case insensitive.

Starting from igraph 0.8.0, you can also include literals here, via igraph's formula notation (see graph_from_literal()). In this case, the first term of the formula has to start with a ‘~’ character, just like regular formulae in R. See examples below.

...

For make_graph(): extra arguments for the case when the graph is given via a literal, see graph_from_literal(). For directed_graph() and undirected_graph(): Passed to make_directed_graph() or make_undirected_graph().

n

The number of vertices in the graph. This argument is ignored (with a warning) if edges are symbolic vertex names. It is also ignored if there is a bigger vertex id in edges. This means that for this function it is safe to supply zero here if the vertex with the largest id is not an isolate.

isolates

Character vector, names of isolate vertices, for symbolic edge lists. It is ignored for numeric edge lists.

directed

Whether to create a directed graph.

dir

It is the same as directed, for compatibility. Do not give both of them.

simplify

For graph literals, whether to simplify the graph.