scale_colour_continuous_sequential: HCL-Based Continuous Sequential Color Scales for ggplot2

In colorspace: A Toolbox for Manipulating and Assessing Colors and Palettes

HCL-Based Continuous Sequential Color Scales for ggplot2

Description

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

Usage

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)

colorspace documentation built on Sept. 11, 2024, 7:05 p.m.