Shape scale

Declare the scale for a mapped (discrete) shape aesthetic. Levels cycle through a default set of marker shapes unless values is given. A shape legend is drawn automatically.

Usage

scale_shape(plot, values = NULL, name = NULL)

Arguments

plot

A PlotSpec.

values

Character vector of shapes, or NULL for the default. Each is either a built-in marker ("circle", "square", "triangle", "diamond", "plus", "cross", "triangle_down", "star") or an SVG icon — a path d string (what icon sets ship) or a path to a .svg file. SVG values are drawn as crisp vector markers (via vellum::svg_grob()) and the legend shows the icon; the size aesthetic scales them.

name

Legend title, or NULL to derive from the encoding.

Value

The modified PlotSpec.

Examples

vplot(mtcars) |> mark_point(x = wt, y = mpg, shape = factor(cyl))

# SVG icon markers, one per level:
star <- "M12 2l3 7h7l-5.5 4.5 2 7-6.5-4.5-6.5 4.5 2-7L2 9h7z"
vplot(mtcars) |>
  mark_point(x = wt, y = mpg, shape = factor(cyl)) |>
  scale_shape(values = c(star, star, star))