get.incidence: Incidence matrix of a bipartite graph
Description
This function can return a sparse or dense incidence matrix
of a bipartite network. The incidence matrix is an $n$ times $m$
matrix, $n$ and $m$ are the number of vertices of the two kinds.
The input graph. The direction of the edges is ignored in
directed graphs.
types
An optional vertex type vector to use instead of the
type vertex attribute. You must supply this argument
if the graph has no type vertex attribute.
attr
Either NULL or a character string giving an edge
attribute name. If NULL, then a traditional incidence matrix is
returned. If not NULL then the values of the given edge
attribute are included in the incid
names
Logical scalar, if TRUE and the vertices in the
graph are named (i.e. the graph has a vertex attribute called
name), then vertex names will be added to the result
as row and column names. Otherwise the ids of the vert
sparse
Logical scalar, if it is TRUE then a sparse
matrix is created, you will need the Matrix package for this.
Value
A sparse or dense matrix.
concept
Bipartite graph
Two-mode network
Incidence matrix
Details
Bipartite graphs have a type vertex attribute in
igraph, this is boolean and FALSE for the vertices of the first
kind and TRUE for vertices of the second kind.