graph.union() was renamed to union.igraph() to create a more
consistent API.
Arguments
- ...
Graph objects or lists of graph objects.
- byname
A logical scalar, or the character scalar
auto. Whether to perform the operation based on symbolic vertex names. If it isauto, that meansTRUEif all graphs are named andFALSEotherwise. A warning is generated ifautoand some (but not all) graphs are named.
