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 e1a80af U--- 10 35 -- Ring graph
#> + attr: name (g/c), mutual (g/l), circular (g/l)
#> + edges from e1a80af:
#> [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 235f3ac 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 235f3ac:
#> [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