The new edges are given as a vertex sequence, e.g. internal
numeric vertex ids, or vertex names. The first edge points from
edges[1] to edges[2], the second from edges[3]
to edges[4], etc.

Usage

add_edges(graph, edges, ..., attr = list())

Arguments

graph

The input graph

edges

The edges to add, a vertex sequence with even number
of vertices.

...

Additional arguments, they must be named,
and they will be added as edge attributes, for the newly added
edges. See also details below.

attr

A named list, its elements will be added
as edge attributes, for the newly added edges. See also details
below.

Value

The graph, with the edges (and attributes) added.

Details

If attributes are supplied, and they are not present in the graph,
their values for the original edges of the graph are set to NA.