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Mark an edge as curved in dagify formulas

Source: R/dagify.R
curved.Rd

Use curved() inside dagify() formulas to specify per-edge curvature. This function should only be used inside dagify() formulas; calling it directly will result in an error, similar to dplyr::n().

Usage

curved(var, curvature = 0.3)

Arguments

var

A variable name (unquoted) representing the parent node.

curvature

A numeric curvature value. Positive values curve edges in one direction, negative in the other. Default is 0.3.

Value

This function is not intended to be called directly. It is detected in the formula AST by dagify().

Curvature sign convention

The curvature value is passed directly to the active edge rendering engine. The ggraph engine (default) and ggarrow engine interpret the sign differently:

  • ggraph: positive curvature curves above (to the left of) a left-to-right edge.

  • ggarrow / grid: positive curvature curves below (to the right of) a left-to-right edge, following grid::curveGrob() convention.

This means the same curvature value will render as a mirror image depending on the engine. ggdag does not negate or transform the value; each engine uses its native convention.

Examples

# Curve the edge from m to y
dagify(
  y ~ x + curved(m, 0.5),
  m ~ x
)
#> dag {
#> m
#> x
#> y
#> m -> y
#> x -> m
#> x -> y
#> }