2D binned heatmap layer — mark

Divides the x-y plane into rectangular bins and fills each by the count (or another aggregation) of observations it holds. The rectangular sibling of mark_hex(): exact bin boundaries make counts easier to read against the axes, hex bins pack denser.

Usage

mark_bin2d(
  plot,
  mapping = NULL,
  data = NULL,
  position = NULL,
  ...,
  bins = NULL,
  binwidth = NULL,
  rasterize = FALSE,
  rasterize_dpi = 300,
  rasterize_dev = "cairo"
)

Arguments

plot: A plotit object
mapping: Optional new aesthetics
data: Optional data for this layer
position: Position adjustment.
...: Other arguments passed to geom_bin_2d
bins: Number of bins along each axis (default 30).
binwidth: Bin width along each axis; overrides bins when given.
rasterize: If TRUE, rasterize via ggrastr::rasterise().
rasterize_dpi: DPI for rasterization (default 300).
rasterize_dev: Graphics device for rasterization (default "cairo").

Value

Modified plotit object

Details

The bin-count fill is owned by this closed statistical mark: it defaults to the sequential viridis scale (colour-blind safe). Chain scale_fill() afterwards to replace it (last call wins).

References

Vega-Lite: Rect with bin transform

AntV G2: Heatmap (corelib)

Examples

plotit(ggplot2::diamonds, encode(x = carat, y = price)) |>
  mark_bin2d(bins = 20)


plotit(faithful, encode(x = eruptions, y = waiting)) |>
  mark_bin2d(bins = 15) |>
  scale_fill(trans = "binned")
#> Scale for fill is already present.
#> Adding another scale for fill, which will replace the existing scale.