R: Bonus color palettes

ColorPalettes {squash} | R Documentation

## Bonus color palettes

### 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)

[Package squash version 1.0.8 Index]