Transform a DAG object into an igraph object

This function extends the as.igraph function from the igraph package to allow the input of a DAG object. The result is an igraph object that includes only the structure of the DAG, without any specifications. May be useful for plotting purposes.

Usage

# S3 method for class 'DAG'
as.igraph(x, include_root_nodes=TRUE,
          include_td_nodes=TRUE, include_networks=FALSE, ...)

Arguments

x

A DAG object created using the empty_dag function with nodes added to it using the + syntax. See ?empty_dag or ?node for more details. Supports DAGs with time-dependent nodes added using the node_td function. However, including such DAGs may result in cyclic causal structures, because time is not represented in the output matrix.

include_root_nodes

Whether to include root nodes in the output matrix. Should usually be kept at TRUE (default).

include_td_nodes

Whether to include time-dependent nodes added to the dag using the node_td function or not. When including these types of nodes, it is possible for the adjacency matrix to contain cycles, e.g. that it is not a classic DAG anymore, due to the matrix not representing the passage of time.

include_networks

Whether to include time-fixed networks added to the dag using the network function or not. Usually it does not make sense to include those, because they are not classical nodes.

...

Currently not used.

Author

Robin Denz

Value

Returns an igraph object.

See also

empty_dag, node, node_td

Examples

library(simDAG)

# some example DAG
dag <- empty_dag() +
  node("death", type="binomial", parents=c("age", "sex"), betas=c(1, 2),
       intercept=-10) +
  node("age", type="rnorm", mean=10, sd=2) +
  node("sex", parents="", type="rbernoulli", p=0.5) +
  node("smoking", parents=c("sex", "age"), type="binomial",
       betas=c(0.6, 0.2), intercept=-2)

if (requireNamespace("igraph")) {
  g <- igraph::as.igraph(dag)
  plot(g)
}