HCL-Based Continuous Sequential Color Scales for ggplot2 — scale_colour_continuous

Continuous ggplot2 color scales using the color palettes generated by sequential_hcl.

scale_colour_continuous_sequential(
  palette = NULL,
  c1 = NULL,
  c2 = NULL,
  cmax = NULL,
  l1 = NULL,
  l2 = NULL,
  h1 = NULL,
  h2 = NULL,
  p1 = NULL,
  p2 = NULL,
  alpha = 1,
  rev = TRUE,
  begin = 0,
  end = 1,
  na.value = "grey50",
  guide = "colourbar",
  aesthetics = "colour",
  n_interp = 11,
  ...
)

scale_color_continuous_sequential(
  palette = NULL,
  c1 = NULL,
  c2 = NULL,
  cmax = NULL,
  l1 = NULL,
  l2 = NULL,
  h1 = NULL,
  h2 = NULL,
  p1 = NULL,
  p2 = NULL,
  alpha = 1,
  rev = TRUE,
  begin = 0,
  end = 1,
  na.value = "grey50",
  guide = "colourbar",
  aesthetics = "colour",
  n_interp = 11,
  ...
)

scale_fill_continuous_sequential(..., aesthetics = "fill")

Arguments

palette: The name of the palette to be used. Run hcl_palettes(type = "sequential") for available options.
c1: Beginning chroma value.
c2: Ending chroma value.
cmax: Maximum chroma value.
l1: Beginning luminance value.
l2: Ending luminance value.
h1: Beginning hue value.
h2: Ending hue value. If set to NA, generates a single-hue scale.
p1: Control parameter determining how chroma should vary (1 = linear, 2 = quadratic, etc.).
p2: Control parameter determining how luminance should vary (1 = linear, 2 = quadratic, etc.).
alpha: Numeric vector of values in the range [0, 1] for alpha transparency channel (0 means transparent and 1 means opaque).
rev: If TRUE (default), reverses the order of the colors in the color scale (compared to sequential_hcl).
begin: Number in the range of [0, 1] indicating to which point in the color scale the smallest data value should be mapped.
end: Number in the range of [0, 1] indicating to which point in the color scale the largest data value should be mapped.
na.value: Color to be used for missing data points.
guide: Type of legend. Use "colourbar" for continuous color bar.
aesthetics: The ggplot2 aesthetics to which this scale should be applied.
n_interp: Number of discrete colors that should be used to interpolate the continuous color scale. 11 will work fine in most cases.
...: common continuous scale parameters: `name`, `breaks`, `labels`, and `limits`. See continuous_scale for more details.

Details

If both a valid palette name and palette parameters are provided then the provided palette parameters overwrite the parameters in the named palette. This enables easy customization of named palettes.

Compared to sequential_hcl the ordering of the colors in the sequential ggplot2 scale are reversed by default (i.e., rev = TRUE) to be more consistent with ggplot2's own scales such as scale_color_brewer. For most named palettes this leads to darker and more colorful colors for larger values on the scale. This is typically the better default on light/white backgrounds.

Examples

library("ggplot2")

# base plot
gg <- ggplot(iris, aes(x = Species, y = Sepal.Width, color = Sepal.Length)) + 
  geom_jitter(width = 0.3) + theme_minimal()

# default settings
gg + scale_color_continuous_sequential()


# switch palette and overwrite some default values
gg + scale_color_continuous_sequential(palette = "Reds", l1 = 20, c2 = 70, p1 = 1)


# select a range out of the entire palette
gg + scale_color_continuous_sequential(palette = "Heat", begin = 0.2, end = 0.8)


# volcano plot
df <- data.frame(height = c(volcano), x = c(row(volcano)), y = c(col(volcano)))
ggplot(df, aes(x, y, fill = height)) + 
  geom_raster() + scale_fill_continuous_sequential(palette = "Terrain", rev = FALSE) +
  coord_fixed(expand = FALSE)