Color scale — scale_color • plotit

Maps data values to colours. Auto-detects discrete vs continuous variables; supports manual colour vectors and named colour schemes.

Usage

scale_color(
  plot,
  name = ggplot2::waiver(),
  trans = NULL,
  limits = NULL,
  range = NULL,
  breaks = NULL,
  labels = NULL,
  na_color = NULL,
  n_bins = NULL,
  mid = NULL,
  ...
)

Arguments

plot: A plotit object.
name: Scale title (legend name). ggplot2::waiver() = use variable name.
trans: Scale transformation. NULL auto-detects, otherwise one of: "identity", "discrete", "reverse", "binned". Unsupported values (e.g. "log") produce a targeted error message.
limits: Data domain. c(min, max) for continuous; character vector for discrete limits.
range: Output range. NULL = auto (discrete->friendly, continuous->viridis). A colour vector (c("blue","red")) for manual colours, or a scheme name: "viridis", "brewer", "grey", "friendly", "hue". For binned: only "viridis", "brewer". For continuous: only "viridis", "brewer".
breaks: Legend key positions.
labels: Legend key labels.
na_color: Colour used for NA values (passed to na.value). NULL = ggplot2 default.
n_bins: Bin a continuous scale into this many legend steps (guide_coloursteps; shorthand for trans = "binned"). NULL = continuous.
mid: Centre of a diverging colour scale (e.g. 0 for correlation matrices). Requires a continuous scale and a diverging scheme in range ("rdbu" default); mutually exclusive with n_bins.
...: Passed to the underlying ggplot2 scale function.

Value

A modified plotit object.

Examples

plotit(iris, encode(x = Sepal.Width, y = Sepal.Length, colour = Species)) |>
  mark_point() |>
  scale_color(range = "viridis")
#> Warning: `range` = "viridis" with a discrete "colour" variable uses the discrete
#> "viridis" variant.
#> ℹ For a continuous gradient, map a numeric column instead.
#> Scale for colour is already present.
#> Adding another scale for colour, which will replace the existing scale.