Set curvature for multiple edges at once

set_curve_edges() replaces all edge curvatures on a dagitty or tidy_dagitty object from a data frame. Use curve_edge() to set a single edge.

Usage

set_curve_edges(.dag, edges)

Arguments

.dag

A dagitty or tidy_dagitty object.

edges

A data frame with columns from, to, and curvature.

Value

The modified .dag object with updated curvatures.

Curvature sign convention

Per-edge curvature is drawn by the ggarrow edge engine only. Set it with edge_engine = "ggarrow" on geom_dag() and the ggdag_*() quick plots, or globally with ggdag_options_set(edge_engine = "ggarrow"); the default ggraph engine draws every edge with the curvature of its own edge type and warns when it is handed a per-edge value it cannot draw.

ggarrow follows the grid::curveGrob() convention, so positive curvature curves below (to the right of) a left-to-right edge and negative curvature curves above it. ggdag passes the value through untouched.

A bidirected edge has no direction of its own, so ggdag draws it from the endpoint dagitty stores first. Naming its endpoints the other way round, as in curve_edge(dag, "y", "x", 0.5) for an edge stored as x <-> y, curves the edge to the same side of the page: the sign is flipped to match the direction the edge is drawn in.

Examples

dag <- dagify(y ~ x + m, m ~ x)
edges <- data.frame(
  from = c("x", "m"),
  to = c("y", "y"),
  curvature = c(0.3, -0.4)
)
dag <- set_curve_edges(dag, edges)