Rasterise the layers of a plot

Render the point and line layers of a ggplot or patchwork object as raster images, while the axes, text, legends and the remaining layers stay vector. A figure with a large number of elements then stays small and quick to draw, in the file and in the browser. For a patchwork composite the sub-plots are rasterised as well, because a composite carries only the first sub-plot's layers itself. The rasterisation is done by ggrastr::rasterise().

Usage

rasterise_plot(
  plot,
  layers = c("Point", "Tile", "Path", "Line", "Segment"),
  dpi = 300,
  dev = "ragg",
  recurse = TRUE
)

Arguments

plot

A ggplot or patchwork object.

layers

Layer types to rasterise, named without the Geom prefix, so the default "Point" matches geom_point() layers. Add "Violin", "Boxplot" or "Crossbar" to rasterise those layers as well.

dpi

Resolution of the rasterised layers, in dots per inch. Default is 300.

dev

Graphic device used to render the rasterised layers, passed to ggrastr::rasterise(). Default is "ragg", which does not need X11; the "cairo" device of the underlying package does, and is unavailable on many headless machines.

recurse

Whether to rasterise the sub-plots of a patchwork composite. Default is TRUE.

Value

The plot object with its heavy layers rasterised. Objects that are neither a ggplot nor a patchwork are returned unchanged, with a warning.

See also

invert_svg()

Examples

panel <- ggplot2::ggplot(mtcars, ggplot2::aes(wt, mpg)) +
  ggplot2::geom_point() +
  ggplot2::facet_wrap(~cyl)

rasterise_plot(panel)


rasterise_plot(patchwork::wrap_plots(panel, panel), dpi = 150)