is_acyclic: Test whether an undirected graph is acyclic
In nvihrs14/tcherry: Learning the structure of tcherry trees

Description Usage Arguments Details Value Author(s) Examples

Test whether an undirected graph, represented by an adjacency matrix, is acyclic.

1	is_acyclic(adj_matrix)

adj_matrix

The adjacency matrix representing the graph.

Notice that the function cannot cope with loops. If the graph has loops, an error is returned.

A logical value indicating whether the graph is acyclic.

Katrine Kirkeby, enir_tak@hotmail.com

Maria Knudsen, mariaknudsen@hotmail.dk

Ninna Vihrs, ninnavihrs@hotmail.dk

adj_matrix_cyclic <- matrix(c(0, 1, 1, 1,
                              1, 0, 0, 1,
                              1, 0, 0, 0,
                              1, 1, 0, 0),
                             nrow = 4)

is_acyclic(adj_matrix_cyclic)

adj_matrix_acyclic <- matrix(c(0, 0, 1, 1,
                               0, 0, 0, 1,
                               1, 0, 0, 0,
                               1, 1, 0, 0),
                              nrow = 4)

is_acyclic(adj_matrix_acyclic)