| incidence_matrix {rhype} | R Documentation |
Find the Incidence Matrix of a Hypergraph
Description
An incidence matrix has rows indexed by vertices and columns indexed by hyperedges. Each entry is non-zero if the associated vertex is a member of the associated hyperedge. For an oriented hypergraph, this returns a list of two matrices with the first representing incidence to one end of the hyperedges and the second representing incidence to the other end. For a directed hypergraph the first represents incidence to the tail of a hyperedge and the second represents incidence to the head.
Usage
incidence_matrix(hype, augment_oriented = TRUE, as_matrix = FALSE)
Arguments
hype |
A hypergraph object |
augment_oriented |
Whether to augment an oriented hypergraph |
as_matrix |
Whether to coerce the result to a simple matrix |
Details
It is hard to use the incidence matrices of oriented undirected hypergraphs
in calculations. The augment_oriented option turns the hypergraph into a
directed hypergraph, but each hyperedge is represented twice, once pointing
in each direction. This is much easier to use for further calculations.
Value
An incidence matrix or a list of two incidence matrices.
Examples
h1 <- example_hype()
incidence_matrix(h1)
h2 <- example_hype(oriented = TRUE, directed = TRUE)
incidence_matrix(h2)