Get parents of nodes in a caugi

Get parents of node in a graph. Note that not both nodes and index can be given.

Usage

parents(cg, nodes = NULL, index = NULL)

Arguments

cg

A caugi object.

nodes

A vector of node names, a vector of unquoted node names, or an expression combining these with + and c().

index

A vector of node indexes.

Value

Either a character vector of node names (if a single node is requested) or a list of character vectors (if multiple nodes are requested).

See also

Other queries: ancestors(), children(), descendants(), edge_types(), edges(), exogenous(), is_acyclic(), is_caugi(), is_cpdag(), is_dag(), is_empty_caugi(), is_pdag(), is_ug(), markov_blanket(), neighbors(), nodes(), same_nodes(), subgraph()

Examples

cg <- caugi(
  A %-->% B,
  B %-->% C,
  class = "DAG"
)
parents(cg, "A") # NULL
#> NULL
parents(cg, index = 2) # "A"
#> [1] "A"
parents(cg, "B") # "A"
#> [1] "A"
parents(cg, c("B", "C"))
#> $B
#> [1] "A"
#> 
#> $C
#> [1] "B"
#> 
#> $B
#> [1] "A"
#>
#> $C
#> [1] "B"