These functions find the vertices not farther than a given limit from
another fixed vertex, these are called the neighborhood of the vertex.
Note that ego() and neighborhood(),
ego_size() and neighborhood_size(),
make_ego_graph() and make_neighborhood()_graph(),
are synonyms (aliases).
connect(graph, order, mode = c("all", "out", "in", "total"))
ego_size(
graph,
order = 1,
nodes = V(graph),
mode = c("all", "out", "in"),
mindist = 0
)
neighborhood_size(
graph,
order = 1,
nodes = V(graph),
mode = c("all", "out", "in"),
mindist = 0
)
ego(
graph,
order = 1,
nodes = V(graph),
mode = c("all", "out", "in"),
mindist = 0
)
neighborhood(
graph,
order = 1,
nodes = V(graph),
mode = c("all", "out", "in"),
mindist = 0
)
make_ego_graph(
graph,
order = 1,
nodes = V(graph),
mode = c("all", "out", "in"),
mindist = 0
)
make_neighborhood_graph(
graph,
order = 1,
nodes = V(graph),
mode = c("all", "out", "in"),
mindist = 0
)The input graph.
Integer giving the order of the neighborhood.
Character constant, it specifies how to use the direction of
the edges if a directed graph is analyzed. For ‘out’ only the
outgoing edges are followed, so all vertices reachable from the source
vertex in at most order steps are counted. For ‘"in"’ all
vertices from which the source vertex is reachable in at most order
steps are counted. ‘"all"’ ignores the direction of the edges. This
argument is ignored for undirected graphs.
The vertices for which the calculation is performed.
The minimum distance to include the vertex in the result.
ego_size()/neighborhood_size() returns with an integer vector.
ego()/neighborhood() (synonyms) returns A list of igraph.vs or a list of numeric
vectors depending on the value of igraph_opt("return.vs.es"),
see details for performance characteristics.
make_ego_graph()/make_neighborhood_graph() returns with a list of graphs.
connect() returns with a new graph object.
The neighborhood of a given order r of a vertex v includes all
vertices which are closer to v than the order. I.e. order 0 is always
v itself, order 1 is v plus its immediate neighbors, order 2
is order 1 plus the immediate neighbors of the vertices in order 1, etc.
ego_size()/neighborhood_size() (synonyms) returns the size of the neighborhoods of the given order,
for each given vertex.
ego()/neighborhood() (synonyms) returns the vertices belonging to the neighborhoods of the given
order, for each given vertex.
make_ego_graph()/make_neighborhood()_graph() (synonyms) is creates (sub)graphs from all neighborhoods of
the given vertices with the given order parameter. This function preserves
the vertex, edge and graph attributes.
connect() creates a new graph by connecting each vertex to
all other vertices in its neighborhood.
Other functions for manipulating graph structure:
+.igraph(),
add_edges(),
add_vertices(),
complementer(),
compose(),
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()
Other structural.properties:
bfs(),
component_distribution(),
constraint(),
coreness(),
degree(),
dfs(),
distance_table(),
edge_density(),
feedback_arc_set(),
girth(),
is_acyclic(),
is_dag(),
is_matching(),
k_shortest_paths(),
knn(),
reciprocity(),
subcomponent(),
subgraph(),
topo_sort(),
transitivity(),
unfold_tree(),
which_multiple(),
which_mutual()
g <- make_ring(10)
ego_size(g, order = 0, 1:3)
#> [1] 1 1 1
ego_size(g, order = 1, 1:3)
#> [1] 3 3 3
ego_size(g, order = 2, 1:3)
#> [1] 5 5 5
# neighborhood_size() is an alias of ego_size()
neighborhood_size(g, order = 0, 1:3)
#> [1] 1 1 1
neighborhood_size(g, order = 1, 1:3)
#> [1] 3 3 3
neighborhood_size(g, order = 2, 1:3)
#> [1] 5 5 5
ego(g, order = 0, 1:3)
#> [[1]]
#> + 1/10 vertex, from 71be79c:
#> [1] 1
#>
#> [[2]]
#> + 1/10 vertex, from 71be79c:
#> [1] 2
#>
#> [[3]]
#> + 1/10 vertex, from 71be79c:
#> [1] 3
#>
ego(g, order = 1, 1:3)
#> [[1]]
#> + 3/10 vertices, from 71be79c:
#> [1] 1 2 10
#>
#> [[2]]
#> + 3/10 vertices, from 71be79c:
#> [1] 2 1 3
#>
#> [[3]]
#> + 3/10 vertices, from 71be79c:
#> [1] 3 2 4
#>
ego(g, order = 2, 1:3)
#> [[1]]
#> + 5/10 vertices, from 71be79c:
#> [1] 1 2 10 3 9
#>
#> [[2]]
#> + 5/10 vertices, from 71be79c:
#> [1] 2 1 3 10 4
#>
#> [[3]]
#> + 5/10 vertices, from 71be79c:
#> [1] 3 2 4 1 5
#>
# neighborhood() is an alias of ego()
neighborhood(g, order = 0, 1:3)
#> [[1]]
#> + 1/10 vertex, from 71be79c:
#> [1] 1
#>
#> [[2]]
#> + 1/10 vertex, from 71be79c:
#> [1] 2
#>
#> [[3]]
#> + 1/10 vertex, from 71be79c:
#> [1] 3
#>
neighborhood(g, order = 1, 1:3)
#> [[1]]
#> + 3/10 vertices, from 71be79c:
#> [1] 1 2 10
#>
#> [[2]]
#> + 3/10 vertices, from 71be79c:
#> [1] 2 1 3
#>
#> [[3]]
#> + 3/10 vertices, from 71be79c:
#> [1] 3 2 4
#>
neighborhood(g, order = 2, 1:3)
#> [[1]]
#> + 5/10 vertices, from 71be79c:
#> [1] 1 2 10 3 9
#>
#> [[2]]
#> + 5/10 vertices, from 71be79c:
#> [1] 2 1 3 10 4
#>
#> [[3]]
#> + 5/10 vertices, from 71be79c:
#> [1] 3 2 4 1 5
#>
# attributes are preserved
V(g)$name <- c("a", "b", "c", "d", "e", "f", "g", "h", "i", "j")
make_ego_graph(g, order = 2, 1:3)
#> [[1]]
#> IGRAPH 07c6536 UN-- 5 4 -- Ring graph
#> + attr: name (g/c), mutual (g/l), circular (g/l), name (v/c)
#> + edges from 07c6536 (vertex names):
#> [1] a--b b--c a--j i--j
#>
#> [[2]]
#> IGRAPH 80f702f UN-- 5 4 -- Ring graph
#> + attr: name (g/c), mutual (g/l), circular (g/l), name (v/c)
#> + edges from 80f702f (vertex names):
#> [1] a--b b--c c--d a--j
#>
#> [[3]]
#> IGRAPH 218b006 UN-- 5 4 -- Ring graph
#> + attr: name (g/c), mutual (g/l), circular (g/l), name (v/c)
#> + edges from 218b006 (vertex names):
#> [1] a--b b--c c--d d--e
#>
# make_neighborhood_graph() is an alias of make_ego_graph()
make_neighborhood_graph(g, order = 2, 1:3)
#> [[1]]
#> IGRAPH cab3c75 UN-- 5 4 -- Ring graph
#> + attr: name (g/c), mutual (g/l), circular (g/l), name (v/c)
#> + edges from cab3c75 (vertex names):
#> [1] a--b b--c a--j i--j
#>
#> [[2]]
#> IGRAPH 37ff31c UN-- 5 4 -- Ring graph
#> + attr: name (g/c), mutual (g/l), circular (g/l), name (v/c)
#> + edges from 37ff31c (vertex names):
#> [1] a--b b--c c--d a--j
#>
#> [[3]]
#> IGRAPH dcc701b UN-- 5 4 -- Ring graph
#> + attr: name (g/c), mutual (g/l), circular (g/l), name (v/c)
#> + edges from dcc701b (vertex names):
#> [1] a--b b--c c--d d--e
#>
# connecting to the neighborhood
g <- make_ring(10)
g <- connect(g, 2)