Basic query operations to get adjacency

Basic query operations to get adjacency

Usage

edge(graph, eid)

neighbors(graph, vid, mode = 3L)

incident(graph, vid, mode = 3L)

degree(graph, vids = integer(0), mode = 3L, loops = TRUE)

Source

https://igraph.org/c/doc/igraph-Basic.html#basic-query-operations

Arguments

graph

An igraph_ptr object.

eid

An integer value of edge ID.

vid

An integer value of vertex ID.

mode

An integer value of edge type to count; {1: OUT, 2: IN, 3: ALL}.

vids

An integer vector of vertex IDs.

loops

whether self-loop should be counted.

Value

edge() returns the head and tail vertices of an edge.

neighbors() returns the adjacent vertices to a vertex.

incident() returns the incident edges of a vertex.

degree() returns the degrees of vertices in a graph.

See also

as_adjlist() and as_inclist() for the all-vertices version of neighbors() and incident().

is_sink(), is_source(), Vsink(), Vsource() for shortcuts to get zero-degree vertices.

Examples

g = graph_tree(5L)
edge(g, 1L)
#> [1] 1 2
neighbors(g, 1L)
#> [1] 2 3
incident(g, 1L)
#> [1] 1 2
degree(g, mode = 1L)
#> [1] 2 2 0 0 0
degree(g, mode = 2L)
#> [1] 0 1 1 1 1
degree(g, mode = 3L)
#> [1] 2 3 1 1 1