is.dag: Check whether a directed graph is acyclic

In MXM: Feature Selection (Including Multiple Solutions) and Bayesian Networks

Check whether a directed graph is acyclic

Description

Check whether a directed graph is acyclic.

Usage

is.dag(dag)

Arguments

dag

A square matrix representing a directed graph which contains either 0, 1 or 0, 2, and 3. In the first canse where G[i, j] = 1, means there is an arrow from node i to node j. In the second case G[i, j] = 2 and G[j, i] = 3 means that there is an arrow from node i to node j, where the 2 iindcates the arrohead and the 3 inducates the arrowtail.

Details

The topological sort is performed. If it cannot be performed, NAs are returned. Hence, the functions checks for NAs.

Value

A logical value, TRUE if the matrix represents a DAG and FALSE otherwise.

Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris [e-mail]

References

Chickering, D.M. (1995). A transformational characterization of equivalent Bayesian network structures. Proceedings of the 11th Conference on Uncertainty in Artificial Intelligence, Montreal, Canada, 87-98.

See Also

topological_sort, dag2eg, pc.or

Examples

# simulate a dataset with continuous data
# simulate a dataset with continuous data
G <- rdag(100, 20, 0.3)$G
is.dag(G)  ## TRUE 

MXM documentation built on Aug. 25, 2022, 9:05 a.m.