huePal: Create (named) single-hue gradient palette

In david-barnett/hueR: Create Grouped Palettes from Hue values

Description

Function to create create HCL palette of n colours based on fixed hue. Luminance monotonically increases, whilst chroma increases and then decreases.

If names provided: return named palette of same length as unique(names), with n distinct colours (if n is left null, all colours are unique)

If the hue value is left as NULL, a function will be returned, which can generate a palette when given a hue values and n and/or names

Usage

huePal(
  hue = NULL,
  names = NULL,
  n = NULL,
  minChroma = 40,
  maxChroma = 150,
  minLum = 10,
  maxLum = 98,
  power = 0.8
)

Arguments

hue	numeric hue value, or NULL to return palette function
names	names for palette, or NULL for unnamed palette of length n
n	number of unique shades in palette
minChroma	minimum Chroma for palette
maxChroma	maximum Chroma for palette
minLum	minimum luminance for palette
maxLum	maximum luminance for palette
power	power used by colorspace::sequential_hcl()

Details

Uses colorspace::sequential_hcl() with a fixed hue to generate palettes.

The palette generated will be roughly centered around the midpoint of the luminance range, and at approximately the maximum chroma.

Note that edges of generated palette are cut off so min and max luminances are never returned. This is because they are, by default, too dark/light to be distinguishable across hues.

Value

vector of colours, possibly named, or a function

Examples

pal <- huePal(hue = 120, n = 9)
scales::show_col(pal, borders = NA)
huePal(hue = 120, names = letters[1:9]) == huePal(hue = 120, n = 9)

# more names than shades --> repeats last shade
extendedPal <- huePal(hue = 120, names = letters[1:16], n = 9)
scales::show_col(extendedPal, borders = NA)

david-barnett/hueR documentation built on Dec. 19, 2021, 9:03 p.m.