ColorPalettes: Bonus color palettes

In squash: Color-Based Plots for Multivariate Visualization

Description

Generate a vector of contiguous colors of a specified length.

Usage

rainbow2(n)
jet(n)
heat(n)
coolheat(n)
blueorange(n)
bluered(n)
darkbluered(n)
greyscale(n, start = 0.9, end = 0)
grayscale(n, start = 0.9, end = 0)

Arguments

n	Number of colors to return.
start, end	Levels of gray (1 = white, 0 = black).

Details

rainbow2 is a variation of rainbow, in which the colors do not cycle completely around. Thus, rainbow2 may be less ambiguous as a color scale.

jet is similar to the Matlab color scheme of the same name and is taken from an example in colorRamp.

heat is similar to heat.colors, but starts at black rather than red.

coolheat is the diverging version of heat, running from cyan to black to yellow.

blueorange and bluered range from blue to grey to orange (or red), and are intended to be used as diverging color scales.

darkbluered ranges from dark blue to grey to dark red, and is intended to be used as a diverging color scale that emphasizes the magnitude more than the sign.

greyscale or grayscale ranges from off-white to black.

Value

A vector of RGB colors.

See Also

Standard R palettes such as rainbow.

Custom palettes can be generated with colorRamp.

Examples

## Present the squash palettes along with the built-in R palettes
squash.palettes <- c('rainbow2', 'jet', 'grayscale', 'heat', 
                     'coolheat', 'blueorange', 'bluered', 'darkbluered')
R.palettes <- c('rainbow', 'heat.colors', 'terrain.colors', 'topo.colors', 'cm.colors')

plot(0:8, type = 'n', ann = FALSE, axes = FALSE)
for (i in 1:5) {
  p <- R.palettes[i]
  hkey(makecmap(c(0, 9), colFn = get(p)), 
    title = p, x = 2, y = i - 1)
}
for (i in 1:8) {
  p <- squash.palettes[i]
  hkey(makecmap(c(0, 9), colFn = get(p)), 
    title = p, x = 6, y = i - 1)
}
text(3, 8, 'R palettes', font = 2)
text(7, 8, 'squash palettes', font = 2)

squash documentation built on Feb. 20, 2020, 9:08 a.m.