network (version 1.0-1)

add.edges: Add Edges to a Network Object

Description

Add one or more edges to an existing network object.

Usage

add.edge(x, tail, head, names.eval=NULL, vals.eval=NULL, 
    edge.check=FALSE, ...)
add.edges(x, tail, head, names.eval=NULL, vals.eval=NULL, ...)

Arguments

x

an object of class network

tail

for add.edge, a vector of vertex IDs reflecting the tail set for the edge to be added; for add.edges, a list of such vectors

head

for add.edge, a vector of vertex IDs reflecting the head set for the edge to be added; for add.edges, a list of such vectors

names.eval

for add.edge, an optional list of names for edge attributes; for add.edges, a list of such lists

vals.eval

for add.edge, an optional list of edge attribute values (matching names.eval); for add.edges, a list of such lists

edge.check

logical; should we perform (computationally expensive) tests to check for the legality of submitted edges?

...

additional arguments

Value

• Invisibly, add.edge and add.edges return pointers to their modified arguments; both functions modify their arguments in place..

Details

The edge checking procedure is very slow, but should always be employed when debugging; without it, one cannot guarantee that the network state is consistent with network level variables (see network.indicators).

Edges can also be added/removed via the extraction/replacement operators. See the associated man page for details.

References

Butts, C.T. 2002. ``Memory Structures for Relational Data in R: Classes and Interfaces'' Working Paper.

See Also

network, add.vertices, network.extraction

Examples

#Initialize a small, empty network
g<-network.initialize(3)

#Add an edge
add.edge(g,1,2)
g

#Can also add edges using the extraction/replacement operators
g[,3]<-1
g[,]