as.undirected() was renamed to as_undirected() to create a more
consistent API.
as.undirected(
graph,
mode = c("collapse", "each", "mutual"),
edge.attr.comb = igraph_opt("edge.attr.comb")
)The graph to convert.
Character constant, defines the conversion algorithm. For
as_directed() it can be mutual or arbitrary. For
as_undirected() it can be each, collapse or
mutual. See details below.
Specifies what to do with edge attributes, if
mode="collapse" or mode="mutual". In these cases many edges
might be mapped to a single one in the new graph, and their attributes are
combined. Please see attribute.combination() for details on
this.