Polar / radial coordinate system

Maps one axis to angle and the other to radius. Default (full circle, zero inner radius) uses coord_polar(). Set inner_radius > 0 or r_axis_inside = TRUE to switch to the radial variant.

Usage

project_polar(
  plot,
  theta = "x",
  start = 0,
  end = NULL,
  direction = 1,
  inner_radius = 0,
  r_axis_inside = FALSE,
  clip = "on",
  reverse = "none",
  rotate_angle = FALSE,
  ...
)

Arguments

plot

A plotit object.

theta

Variable mapped to angle: "x" or "y".

start

Starting angle in radians (0 = 12 o'clock).

end

Ending angle in radians (radial mode only). NULL (default) = full circle; a finite value renders a partial arc (e.g. semicircle gauges via start = -pi / 2, end = pi / 2). Ignored with a warning in plain polar mode.

direction

1 = clockwise, -1 = anti-clockwise. Deprecated: use reverse = "theta". -1 still works but warns once per call (deprecation cycle, AGENTS.md 1.4).

inner_radius

Inner radius as a fraction of the panel (0-1). 0 = polar (full circle). >0 = radial (hollow centre).

r_axis_inside

If TRUE, place the radial axis inside the panel (radial mode only).

clip

Should drawing be clipped? "on" or "off".

reverse

Reverse direction: "none" (default), "theta" (anti-clockwise, replaces direction = -1), "r" (radial axis) or "thetar" (both). "r"/"thetar" are radial-mode only.

rotate_angle

Rotate angle aesthetics with the theta axis (radial mode only, ggplot2 coord_radial(rotate.angle)).

...

Passed to the underlying coord_polar() or coord_radial().

Value

Modified plotit object.

Examples

plotit(mtcars, encode(x = factor(cyl))) |>
  mark_bar() |>
  project_polar()