ggrastr (version 1.0.2)

rasterise: Rasterise ggplot layers Takes a ggplot object or a layer as input and renders their graphical output as a raster.

Description

Rasterise ggplot layers Takes a ggplot object or a layer as input and renders their graphical output as a raster.

Usage

rasterise(input, ...)
# S3 method for Layer
rasterise(input, ..., dpi = NULL, dev = "cairo", scale = 1)
# S3 method for list
rasterise(input, ..., dpi = NULL, dev = "cairo", scale = 1)
# S3 method for ggplot
rasterise(
  input,
  ...,
  layers = c("Point", "Tile"),
  dpi = NULL,
  dev = "cairo",
  scale = 1
)

Value

A modified Layer object.

Arguments

input

ggplot plot object to rasterize

...

ignored

dpi

integer Sets the desired resolution in dots per inch (default=NULL).

dev

string Specifies the device used, which can be one of: "cairo", "ragg", "ragg_png" or "cairo_png" (default="cairo").

scale

numeric Scaling factor to modify the raster object size (default=1). The parameter 'scale=1' results in an object size that is unchanged, 'scale'>1 increase the size, and 'scale'<1 decreases the size. These parameters are passed to 'height' and 'width' of grid::grid.raster(). Please refer to 'rasterise()' and 'grid::grid.raster()' for more details.

layers

list of layer types that should be rasterized

Author

Teun van den Brand <[e-mail]>

Details

The default dpi (NULL (i.e. let the device decide)) can conveniently be controlled by setting the option "ggrastr.default.dpi" (e.g. options("ggrastr.default.dpi" = 30) for drafting).

Examples

require(ggplot2)
# `rasterise()` is used to wrap layers
ggplot(pressure, aes(temperature, pressure)) +
  rasterise(geom_line())

# The `dpi` argument controls resolution
ggplot(faithful, aes(eruptions, waiting)) +
  rasterise(geom_point(), dpi = 5)

# The `dev` argument offers a few options for devices
require(ragg)
ggplot(diamonds, aes(carat, depth, z = price)) +
  rasterise(stat_summary_hex(), dev = "ragg")

# The `scale` argument allows you to render a 'big' plot in small window, or vice versa.
ggplot(faithful, aes(eruptions, waiting)) +
  rasterise(geom_point(), scale = 4)