AncestralRelations {dagitty}

Ancestral Relations

Description

Retrieve the names of all variables in a given graph that are in the specified ancestral relationship to the input variable v.

Usage

descendants(x, v, proper = FALSE)

ancestors(x, v, proper = FALSE)

children(x, v)

parents(x, v)

neighbours(x, v)

spouses(x, v)

adjacentNodes(x, v)

markovBlanket(x, v)

Arguments

x

the input graph, of any type.

v

name(s) of variable(s).

proper

logical. By default (proper=FALSE), the descendants or ancestors of a variable include the variable itself. For (proper=TRUE), the variable itself is not included.

descendants(x,v) retrieves variables that are are reachable from v via a directed path.

ancestors(x,v) retrieves variables from which v is reachable via a directed path.

children(x,v) finds all variables w connected to v by an edge v -> w.

parents(x,v) finds all variables w connected to v by an edge w -> v.

markovBlanket(x,v) returns x's parents, its children, and all other parents of its children. The Markov blanket always renders x independent of all other nodes in the graph.

By convention, descendants(x,v) and ancestors(x,v) include v but children(x,v) and parents(x,v) do not.

Examples

g <- dagitty("graph{ a <-> x -> b ; c -- x <- d }")
# Includes "x"
descendants(g,"x")
# Does not include "x"
descendants(g,"x",TRUE)
parents(g,"x")
spouses(g,"x")