Area, ribbon, and step marks

mark_area() fills the region between a y line and the zero baseline; mark_ribbon() fills between ymin and ymax; mark_step() draws a staircase line. All connect points in x order.

Usage

mark_area(
  plot,
  ...,
  position = "stack",
  blend = NULL,
  sketch = NULL,
  data = NULL
)

mark_ribbon(plot, ..., blend = NULL, sketch = NULL, data = NULL)

mark_step(
  plot,
  ...,
  direction = "hv",
  blend = NULL,
  effects = list(),
  sketch = NULL,
  data = NULL
)

Arguments

plot

A PlotSpec (from vplot()).

...

Encodings (tidy-eval): x and y for area/step; x, ymin, ymax for ribbon; plus color/fill/alpha.

position

For mark_area(), how areas sharing an x combine when fill/color is mapped: "stack" (default) stacks them into a band, "fill" normalises each x to 1, "identity" overlays them from the zero baseline. With no fill mapping all three are equivalent (a single area).

blend

Optional blend mode for compositing this layer against what is already drawn beneath it (the panel and earlier layers), one of the CSS mix-blend-mode names, e.g. "multiply", "screen", "darken". The whole layer composites as one isolated group (not per element).

sketch

A sketch() spec giving this layer a hand-drawn look (wobbly outlines, hachure fills), NA/FALSE to force it crisp (overriding a plot-wide theme_sketch()), or NULL (default) to inherit. Geometry marks accept it; text, raster, hex and datashade marks do not.

data

Optional layer data frame; overrides the plot data for this layer.

direction

For mark_step(), "hv" (horizontal then vertical, default) or "vh".

effects

A list of layer render effects applied to the mark at draw time — glow(), outline(), and shadow(). Available on stroked and point marks.

Value

The modified PlotSpec.

Examples

vplot(pressure) |> mark_area(x = temperature, y = pressure)