neighbors: Get neighbors of nodes in a 'caugi'

In caugi: Causal Graph Interface

Get neighbors of nodes in a caugi

Description

Get neighbors of a node in the graph, optionally filtered by edge direction or type. This function works for all graph classes including UNKNOWN.

Usage

neighbors(cg, nodes = NULL, index = NULL, mode = "all")

neighbours(cg, nodes = NULL, index = NULL, mode = "all")

Arguments

cg	A caugi object.
nodes	A character vector of node names.
index	A vector of node indexes.
mode	Character; specifies which types of neighbors to return: "all" All neighbors (default) "in" Parents: nodes with directed edges pointing INTO the target node (equivalent to parents()) "out" Children: nodes with directed edges pointing OUT from the target node (equivalent to children()) "undirected" Nodes connected via undirected (⁠---⁠) edges "bidirected" Nodes connected via bidirected (⁠<->⁠) edges (equivalent to spouses() for ADMGs) "partial" Nodes connected via partial edges (edges with circle endpoints: o-o, ⁠o->⁠, --o) Not all modes are valid for all graph classes: DAG: "in", "out", "all" only PDAG: "in", "out", "undirected", "all" UG: "undirected", "all" only ADMG: "in", "out", "bidirected", "all" UNKNOWN: all modes allowed

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(), anteriors(), children(), components(), descendants(), districts(), edge_types(), edges(), exogenous(), is_acyclic(), is_admg(), is_ag(), is_caugi(), is_cpdag(), is_dag(), is_empty_caugi(), is_mag(), is_mpdag(), is_pdag(), is_simple(), is_ug(), m_separated(), markov_blanket(), nodes(), parents(), posteriors(), same_nodes(), spouses(), subgraph(), topological_sort()

Examples

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

# Using mode to filter by edge direction
neighbors(cg, "B", mode = "in") # "A" (parents)
neighbors(cg, "B", mode = "out") # "C" (children)

# Works for UNKNOWN graphs too
cg_unknown <- caugi(
  A %-->% B,
  B %---% C,
  C %o->% D,
  class = "UNKNOWN"
)
neighbors(cg_unknown, "B", mode = "in") # "A"
neighbors(cg_unknown, "B", mode = "undirected") # "C"
neighbors(cg_unknown, "C", mode = "partial") # "D"

caugi documentation built on Oct. 28, 2026, 1:07 a.m.