as.network.matrix: Coercion from Matrices to Network Objects

In network: Classes for Relational Data

Coercion from Matrices to Network Objects

Description

as.network.matrix attempts to coerce its first argument to an object of class network.

Usage

## Default S3 method:
as.network(x, ...)

## S3 method for class 'matrix'
as.network(
  x,
  matrix.type = NULL,
  directed = TRUE,
  hyper = FALSE,
  loops = FALSE,
  multiple = FALSE,
  bipartite = FALSE,
  ignore.eval = TRUE,
  names.eval = NULL,
  na.rm = FALSE,
  edge.check = FALSE,
  ...
)

Arguments

x	a matrix containing an adjacency structure
...	additional arguments
matrix.type	one of "adjacency", "edgelist", "incidence", or NULL
directed	logical; should edges be interpreted as directed?
hyper	logical; are hyperedges allowed?
loops	logical; should loops be allowed?
multiple	logical; are multiplex edges allowed?
bipartite	count; should the network be interpreted as bipartite? If present (i.e., non-NULL) it is the count of the number of actors in the bipartite network. In this case, the number of nodes is equal to the number of actors plus the number of events (with all actors preceding all events). The edges are then interpreted as nondirected.
ignore.eval	logical; ignore edge values?
names.eval	optionally, the name of the attribute in which edge values should be stored
na.rm	logical; ignore missing entries when constructing the network?
edge.check	logical; perform consistency checks on new edges?

Details

Depending on matrix.type, one of three edgeset constructor methods will be employed to read the input matrix (see edgeset.constructors). If matrix.type==NULL, which.matrix.type will be used to guess the appropriate matrix type.

The coercion methods will recognize and attempt to utilize the sna extended matrix attributes where feasible. These are as follows:

• "n": taken to indicate number of vertices in the network.

• "bipartite": taken to indicate the network's bipartite attribute, where present.

• "vnames": taken to contain vertex names, where present.

These attributes are generally used with edgelists, and indeed data in sna edgelist format should be transparently converted in most cases. Where the extended matrix attributes are in conflict with the actual contents of x, results are no guaranteed (but the latter will usually override the former). For an edge list, the number of nodes in a network is determined by the number of unique nodes specified. If there are isolate nodes not in the edge list, the "n" attribute needs to be set. See example below.

Value

An object of class network

Author(s)

Carter T. Butts [e-mail] and David Hunter [e-mail]

References

Butts, C. T. (2008). “network: a Package for Managing Relational Data in R.” Journal of Statistical Software, 24(2). https://www.jstatsoft.org/v24/i02/

See Also

edgeset.constructors, network, which.matrix.type

Examples

#Draw a random matrix
m<-matrix(rbinom(25,1,0.5),5)
diag(m)<-0

#Coerce to network form
g<-as.network.matrix(m,matrix.type="adjacency")

# edge list example. Only 4 nodes in the edge list.
m = matrix(c(1,2, 2,3, 3,4), byrow = TRUE, nrow=3)
attr(m, 'n') = 7
as.network(m, matrix.type='edgelist')

network documentation built on Feb. 16, 2023, 6:11 p.m.