isCollider: Test for Colliders

In dagitty: Graphical Analysis of Structural Causal Models

Description

Returns TRUE if three given variables form a collider in a given graph.

Usage

isCollider(x, u, v, w)

Arguments

x	the input graph, a DAG.
u	the first endpoint of the putative collider
v	the midpoint of the putative collider
w	the second endpoint of the putative collider

Examples

g1 <- dagitty("dag{X -> Y -> Z}")
stopifnot( isTRUE(!isCollider( g1, "X", "Y", "Z" )) )
g2 <- dagitty("dag{X -> Y <- Z }")
stopifnot( isTRUE(isCollider( g2, "X", "Y", "Z" )) )

Example output

dagitty documentation built on Jan. 21, 2021, 5:07 p.m.