A complementer graph contains all edges that were not present in the input graph.
Details
complementer() creates the complementer of a graph. Only edges
which are not present in the original graph will be included in the
new graph.
complementer() keeps graph and vertex attriubutes, edge
attributes are lost.
See also
Other functions for manipulating graph structure:
+.igraph(),
add_edges(),
add_vertices(),
compose(),
connect(),
contract(),
delete_edges(),
delete_vertices(),
difference(),
difference.igraph(),
disjoint_union(),
edge(),
igraph-minus,
intersection(),
intersection.igraph(),
path(),
permute(),
rep.igraph(),
reverse_edges(),
simplify(),
union(),
union.igraph(),
vertex()
Author
Gabor Csardi csardi.gabor@gmail.com
Examples
## Complementer of a ring
g <- make_ring(10)
complementer(g)
#> IGRAPH f702a96 U--- 10 35 -- Ring graph
#> + attr: name (g/c), mutual (g/l), circular (g/l)
#> + edges from f702a96:
#> [1] 1-- 9 1-- 8 1-- 7 1-- 6 1-- 5 1-- 4 1-- 3 2--10 2-- 9 2-- 8 2-- 7 2-- 6
#> [13] 2-- 5 2-- 4 3--10 3-- 9 3-- 8 3-- 7 3-- 6 3-- 5 4--10 4-- 9 4-- 8 4-- 7
#> [25] 4-- 6 5--10 5-- 9 5-- 8 5-- 7 6--10 6-- 9 6-- 8 7--10 7-- 9 8--10
## A graph and its complementer give together the full graph
g <- make_ring(10)
gc <- complementer(g)
gu <- union(g, gc)
gu
#> IGRAPH 55baafd U--- 10 45 --
#> + attr: name_1 (g/c), name_2 (g/c), mutual_1 (g/l), mutual_2 (g/l),
#> | circular_1 (g/l), circular_2 (g/l)
#> + edges from 55baafd:
#> [1] 9--10 8--10 8-- 9 7--10 7-- 9 7-- 8 6--10 6-- 9 6-- 8 6-- 7 5--10 5-- 9
#> [13] 5-- 8 5-- 7 5-- 6 4--10 4-- 9 4-- 8 4-- 7 4-- 6 4-- 5 3--10 3-- 9 3-- 8
#> [25] 3-- 7 3-- 6 3-- 5 3-- 4 2--10 2-- 9 2-- 8 2-- 7 2-- 6 2-- 5 2-- 4 2-- 3
#> [37] 1--10 1-- 9 1-- 8 1-- 7 1-- 6 1-- 5 1-- 4 1-- 3 1-- 2
graph.isomorphic(gu, make_full_graph(vcount(g)))
#> [1] TRUE