Compute a layered layout for a UMG

Assigns coordinates by longest-path layering on the directed subgraph: parameters and constants at the top, observed leaves at the bottom, vertices spread horizontally within layers. Plate rectangles are computed as padded bounding boxes of their members, with padding growing by nesting depth so nested plates remain visually distinct. Coordinates can be overridden by supplying a coords data frame, which is the recommended route for publication figures.

Usage

umg_layout(
  model,
  coords = NULL,
  hgap = 1.6,
  vgap = 1.8,
  orientation = c("TB", "LR")
)

Arguments

model

An object of class umg.

coords

Optional data frame with columns name, x, y overriding computed positions.

hgap, vgap

Horizontal and vertical spacing between vertices.

orientation

Layer direction: "TB" (top to bottom, the default) places sources at the top and observed leaves at the bottom; "LR" lays the layers out left to right. NULL is treated as "TB".

Value

The model with a layout component added: a data frame of vertex coordinates and a list of plate rectangles.