Create a wheel graph

A wheel graph is created by connecting a center vertex to all vertices of a cycle graph. A wheel graph on n vertices can be thought of as a wheel with n - 1 spokes. The cycle graph part makes up the rim, while the star graph part adds the spokes.

Note that the two and three-vertex wheel graphs are non-simple: The two-vertex wheel graph contains a self-loop, while the three-vertex wheel graph contains parallel edges (a 1-cycle and a 2-cycle, respectively).

Usage

make_wheel(n, ..., mode = c("in", "out", "mutual", "undirected"), center = 1)

wheel(n, ..., mode = c("in", "out", "mutual", "undirected"), center = 1)

Arguments

n

Number of vertices.

...

These dots are for future extensions and must be empty.

mode

It defines the direction of the edges. in: the edges point to the center, out: the edges point from the center, mutual: a directed wheel is created with mutual edges, undirected: the edges are undirected.

center

ID of the center vertex.

Value

An igraph graph.

See also

Other deterministic constructors: graph_from_atlas(), graph_from_edgelist(), graph_from_literal(), make_(), make_chordal_ring(), make_circulant(), make_empty_graph(), make_full_citation_graph(), make_full_graph(), make_full_multipartite(), make_graph(), make_lattice(), make_ring(), make_star(), make_tree(), make_turan()

Related documentation in the C library

wheel().

Examples

make_wheel(10, mode = "out")
#> IGRAPH 7d0ab96 D--- 10 18 -- Out-wheel
#> + attr: name (g/c), mode (g/c), center (g/n)
#> + edges from 7d0ab96:
#>  [1]  1-> 2  1-> 3  1-> 4  1-> 5  1-> 6  1-> 7  1-> 8  1-> 9  1->10  2-> 3
#> [11]  3-> 4  4-> 5  5-> 6  6-> 7  7-> 8  8-> 9  9->10 10-> 2
make_wheel(5, mode = "undirected")
#> IGRAPH 6d50452 U--- 5 8 -- Wheel
#> + attr: name (g/c), mode (g/c), center (g/n)
#> + edges from 6d50452:
#> [1] 1--2 1--3 1--4 1--5 2--3 3--4 4--5 2--5