structure.info {igraph} | R Documentation |
Functions for exploring the basic structure of a network: number of vertices and edges, the neighbors of a node, test whether two vertices are connected by an edge.
vcount(graph) ecount(graph) neighbors(graph, v, mode = 1) is.directed(graph) are.connected(graph, v1, v2) get.edge(graph, id) get.edges(graph, es)
graph |
The graph. |
v |
The vertex of which the neighbors are queried. |
mode |
Character string, specifying the type of neighboring vertices to list in a directed graph. If “out” the vertices to which an edge exist are listed, if “in” the vertices from which an edge is directed are listed, “all” lists all the vertices. This argument is ignored for undirected graphs. |
v1 |
The id of the first vertex. For directed graphs only edges
pointing from v1 to v2 are searched. |
v2 |
The id of the second vertex. For directed graphs only edges
pointing from v1 to v2 are searched. |
id |
A numeric edge id. |
es |
An edge sequence. |
These functions provide the basic structural information of a graph.
vcount
gives the number of vertices in the graph.
ecount
gives the number of edges in the graph.
neighbors
gives the neighbors of a vertex. The vertices
connected by multiple edges are listed as many times as the number of
connecting edges.
is.directed
gives whether the graph is directed or not. It just
gives its directed
attribute.
are.connected
decides whether there is an edge from v1
to v2
.
get.edge
returns the end points of the edge with the supplied
edge id. For directed graph the source vertex comes first, for
undirected graphs, the order is arbitrary.
get.edges
returns a matrix with the endpoints of the edges in
the edge sequence argument.
vcount
and ecount
return integer
constants. neighbors
returns an integer
vector. is.directed
and are.connected
return boolean
constants. get.edge
returns a numeric vector of length two.
get.edges
returns a two-column matrix.
Gabor Csardi csardi@rmki.kfki.hu
g <- graph.ring(10) vcount(g) ecount(g) neighbors(g, 5) are.connected(g, 1, 2) are.connected(g, 2, 4) get.edges(g, 0:5)