vertex: Helper function for adding and deleting vertices
Description
This is a helper function that simplifies adding and deleting
vertices to/from graphs.
Usage
vertex(...)
vertices(...)
Arguments
...
See details below.
Value
A special object that can be used with together with
igraph graphs and the plus and minus operators.
Details
vertices is an alias for vertex.
When adding vertices via +, all unnamed arguments are interpreted
as vertex names of the new vertices. Named arguments are interpreted as
vertex attributes for the new vertices.
When deleting vertices via -, all arguments of vertex (or
vertices) are concatenated via c() and passed to
delete_vertices.