Check whether a graph is directed
See also
Other structural queries:
[.igraph()
,
[[.igraph()
,
adjacent_vertices()
,
are_adjacent()
,
ends()
,
get.edge.ids()
,
gorder()
,
gsize()
,
head_of()
,
incident()
,
incident_edges()
,
neighbors()
,
tail_of()