Adjusting for a collider activates pathways between the parent of the collider. This geom adds a curved edge between any such parent nodes.

geom_dag_collider_edges(mapping = NULL, data = NULL,
stat = "identity", position = "identity", ..., size = 0.6,
curvature = 0.5, angle = 90, ncp = 5, arrow = NULL,
lineend = "butt", na.rm = FALSE, show.legend = NA,
inherit.aes = TRUE)

## Arguments

mapping Set of aesthetic mappings created by aes() or aes_(). If specified and inherit.aes = TRUE (the default), it is combined with the default mapping at the top level of the plot. You must supply mapping if there is no plot mapping. The data to be displayed in this layer. There are three options: If NULL, the default, the data is inherited from the plot data as specified in the call to ggplot(). A data.frame, or other object, will override the plot data. All objects will be fortified to produce a data frame. See fortify() for which variables will be created. A function will be called with a single argument, the plot data. The return value must be a data.frame., and will be used as the layer data. The statistical transformation to use on the data for this layer, as a string. Position adjustment, either as a string, or the result of a call to a position adjustment function. Other arguments passed on to layer(). These are often aesthetics, used to set an aesthetic to a fixed value, like color = "red" or size = 3. They may also be parameters to the paired geom/stat. a numeric vector of length 1. Edge width A numeric value giving the amount of curvature. Negative values produce left-hand curves, positive values produce right-hand curves, and zero produces a straight line. A numeric value between 0 and 180, giving an amount to skew the control points of the curve. Values less than 90 skew the curve towards the start point and values greater than 90 skew the curve towards the end point. The number of control points used to draw the curve. More control points creates a smoother curve. specification for arrow heads, as created by arrow(). Line end style (round, butt, square). If FALSE, the default, missing values are removed with a warning. If TRUE, missing values are silently removed. logical. Should this layer be included in the legends? NA, the default, includes if any aesthetics are mapped. FALSE never includes, and TRUE always includes. It can also be a named logical vector to finely select the aesthetics to display. If FALSE, overrides the default aesthetics, rather than combining with them. This is most useful for helper functions that define both data and aesthetics and shouldn't inherit behaviour from the default plot specification, e.g. borders().

## Examples

library(dagitty)
dagify(m ~ a + b, x ~ a, y ~ b) %>%
tidy_dagitty() %>%
control_for("m") %>%
ggplot(aes(x = x, y = y, xend = xend, yend = yend, shape = adjusted)) +
geom_dag_edges() +
geom_dag_collider_edges() +
geom_dag_node() +
geom_dag_text() +
theme_dag() +
scale_adjusted()