get.edges
retrieves a list of edges incident on a given vertex; get.edgeIDs
returns the internal identifiers for those edges, instead. Both allow edges to be selected based on vertex neighborhood and (optionally) an additional endpoint.
get.edges(x, v, alter = NULL, neighborhood = c("out", "in", "combined"), na.omit = TRUE)
get.edgeIDs(x, v, alter=NULL, neighborhood=c("out","in","combined"), na.omit=TRUE)
get.dyads.eids(x, tails, heads, neighborhood = c("out", "in", "combined"))
network
v
). defaults to 'combined'
for undirected networks get.edges
, a list of edges. For get.edgeIDs
, a vector of edge ID numbers. For get.edgeIDs
, a list of edge IDs corresponding to the dyads defined by the vertex ids in tails
and heads
get.edges
returns all out-, in-, or out- and in-edges containing v
. get.edgeIDs
is identical, save in its return value, as it returns only the ids of the edges. Specifying a vertex in alter
causes these edges to be further selected such that alter must also belong to the edge -- this can be used to extract edges between two particular vertices. Omission of missing edges is accomplished via na.omit
. Note that for multiplex networks, multiple edges or edge ids can be returned.
The function get.dyads.eids
simplifies the process of looking up the edge ids associated with a set of 'dyads' (tail and head vertex ids) for edges. It only is intended for working with non-multiplex networks and will return a warning and NA
value for any dyads that correspond to multiple edges. The value numeric(0)
will be returned for any dyads that do not have a corresponding edge.
get.neighborhood
, valid.eids
#Create a network with three edges
m<-matrix(0,3,3)
m[1,2]<-1; m[2,3]<-1; m[3,1]<-1
g<-network(m)
get.edges(g,1,neighborhood="out")
get.edgeIDs(g,1,neighborhood="in")
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