A complementer graph contains all edges that were not present in the input graph.
Arguments
- graph
The input graph, can be directed or undirected.
- loops
Logical constant, whether to generate loop edges.
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.igraph(),
difference(),
disjoint_union(),
edge(),
igraph-minus,
intersection.igraph(),
intersection(),
path(),
permute(),
rep.igraph(),
reverse_edges(),
simplify(),
union.igraph(),
union(),
vertex()
Author
Gabor Csardi csardi.gabor@gmail.com
Examples
## Complementer of a ring
g <- make_ring(10)
complementer(g)
#> IGRAPH 3e0b641 U--- 10 35 -- Ring graph
#> + attr: name (g/c), mutual (g/l), circular (g/l)
#> + edges from 3e0b641:
#> [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 8935102 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 8935102:
#> [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