Polar coordinates

coord_polar() projects the panel into polar space: one position aesthetic becomes the angle and the other the radius. With theta = "x" (the default) the x aesthetic maps to angle and y to radius — a categorical bar chart becomes a wind-rose / coxcomb, a line becomes a radar/spider trace, a point cloud is positioned by (angle, radius). With theta = "y" a stacked bar becomes a pie (see also the mark_pie() / mark_donut() shortcuts). The panel is locked to a square. Lines, areas, and ribbons are interpolated into smooth arcs.

Usage

coord_polar(plot, theta = "x", start = 0, direction = 1)

Arguments

plot

A PlotSpec.

theta

Which position aesthetic drives the angle: "x" (default) or "y".

start

Angular offset of the zero position, in radians (0 places the first value at twelve o'clock).

direction

Winding direction: 1 for clockwise (default), -1 for counter-clockwise.

Value

The modified PlotSpec.

See also

mark_pie(), mark_donut()

Examples

vplot(mtcars) |> mark_bar(x = factor(cyl)) |> coord_polar(theta = "x")