Bipartite adjacency matrix of a bipartite graph

This function can return a sparse or dense bipartite adjacency matrix of a bipartite network. The bipartite adjacency matrix is an \(n\) times \(m\) matrix, \(n\) and \(m\) are the number of vertices of the two kinds.

Usage

as_biadjacency_matrix(
  graph,
  types = NULL,
  ...,
  weights = NULL,
  names = TRUE,
  sparse = FALSE,
  attr = deprecated()
)

Arguments

graph

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.

...

These dots are for future extensions and must be empty.

weights

One of the following:

• NULL (default): use the weight edge attribute if the graph has one, otherwise return a traditional (unweighted) adjacency matrix.

• NA: explicitly unweighted, ignoring any weight edge attribute.

• A numeric or logical vector of length ecount(): use these values directly as edge weights.

• A character scalar: the name of an edge attribute whose values are used as weights. The attribute must be numeric or logical.

If multiple edges share endpoints, the value of an arbitrarily chosen edge is included in the matrix.

names

Logical, 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 vertices are used as row and column names.

sparse

Logical, if it is TRUE then a sparse matrix is created, you will need the Matrix package for this.

attr

Use weights instead. If supplied, the value is forwarded to weights as a character edge attribute name.

Value

A sparse or dense 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.

Some authors refer to the bipartite adjacency matrix as the "bipartite incidence matrix". igraph 1.6.0 and later does not use this naming to avoid confusion with the edge-vertex incidence matrix.

Related documentation in the C library

get_biadjacency(), get_edgelist(), vcount(), edges(), get_eids(), ecount()

See also

graph_from_biadjacency_matrix() for the opposite operation.

Other conversion: as.matrix.igraph(), as_adj_list(), as_adjacency_matrix(), as_data_frame(), as_directed(), as_edgelist(), as_graphnel(), as_long_data_frame(), graph_from_adj_list(), graph_from_graphnel()

Author

Gabor Csardi csardi.gabor@gmail.com

Examples

g <- make_bipartite_graph(c(0, 1, 0, 1, 0, 0), c(1, 2, 2, 3, 3, 4))
as_biadjacency_matrix(g)
#>   2 4
#> 1 1 0
#> 3 1 1
#> 5 0 0
#> 6 0 0