as.edgelist: Convert a network object into a numeric edgelist matrix

In network: Classes for Relational Data

Description

Constructs an edgelist in a sorted format with defined attributes.

Usage

  ## S3 method for class 'network'
as.edgelist(x, attrname = NULL, as.sna.edgelist = FALSE, 
  inverted = NULL, ...)
  
  ## S3 method for class 'matrix'
as.edgelist(x, n, directed = TRUE, bipartite = FALSE, 
  loops = FALSE, inverted = FALSE, vnames = seq_len(n), ...)
  
  is.edgelist(x)
  

Arguments

x	a network object with additional class added indicating how it should be dispatched.
attrname	optionally, the name of an edge attribute to use for edge values
as.sna.edgelist	logical; should the edgelist be returned in edgelist form expected by the sna package?
inverted	logical; value is passed to the 'inverted' flag on the edgelist returned
n	integer number of vertices in network, value passed to the 'n' flag on edgelist returned
vnames	vertex names (defaults to vertex ids) to be attached to edgelist for sna package compatibility
directed	logical; is network directed, value passed to the 'directed' flag on edgelist returned
bipartite	logical or integer; is network bipartite, value passed to the 'bipartite' flag on edgelist returned
loops	logical; are self-loops allowed in network?, value passed to the 'loops' flag on edgelist returned
...	additional arguments to other methods

Details

Constructs a edgelist matrix from a network, sorted tails-major order, with tails first, and, for undirected networks, tail < head. This format is required by some reverse-depending packages (i.e. ergm)

The as.matrix.network.edgelist provides similar functionality but it does not enforce ordering or set the edgelist class and so should be slightly faster.

is.edgelist tests if an object has the class 'edgelist'

Value

A matrix in which the first two columns are integers giving the tail (source) and head (target) vertex ids of each edge. The matrix will be given the class edgelist.

The edgelist has additional attributes attached to it:

• attr(,"n") the number of vertices in the original network

• attr(,"vnames") the names of vertices in the original network

• attr(,"directed") logical, was the original network directed

• attr(,"bipartite") was the original network bipartite

• attr(,"loops") does the original network contain self-loops

• attr(,"inverted") indicates if the network has been inverted?

Note that if the attrname attribute is used the resulting edgelist matrix will have three columns. And if attrname refers to a character attribute, the resulting edgelist matrix will be character rather than numeric.

Note

NOTE: this function was moved to network from the ergm package in network version 1.13

See Also

See also as.matrix.network.edgelist

Examples

   data(emon)
   as.edgelist(emon[[1]])
   # contrast with unsorted columns of
   as.matrix.network.edgelist(emon[[1]])
  

network documentation built on May 2, 2019, 5:16 p.m.