R: Matteo Niccoli's perceptually uniform colormaps

niccoli {pals} | R Documentation

## Matteo Niccoli's perceptually uniform colormaps

### Description

These colormaps are intended by be more perceptually balanced than traditional rainbow-like palettes.

### Usage

    cubicyf(n)

    isol(n)

    cubicl(n)

    linearl(n)

    linearlhot(n)

### Arguments

`n` | Number of colors to return

### Details

`isol()`: Lab-based isoluminant rainbow with constant luminance L*=60. Best choice for displaying interval data with external lighting. best for displaying interval data with external lighting. This is so as to allow the lighting to provide the shading to highlight the details of interest. If lighting is combined with a colormap that has its own luminance function associated - even as simple as a linear increase this will confuse the viewer.

`linearl()`: Lab-based linear lightness rainbow. A linear lightness modification of Matlab's 'hot' palette. For interval data displayed without external lighting. 100

`linlhot()`: Linear lightness modification of Matlab's hot color palette. For interval data displayed without external lighting 100

`cubicyf()`: Lab-based rainbow scheme with cubic-law luminance(default) For interval data displayed without external lighting 100

`cubicl()`: Lab-based rainbow scheme with cubic-law luminance For interval data displayed without external lighting Similar to cubicyf(), but has red at high end (a modest deviation from 100

### Value

A vector of colors

### Author(s)

Palettes by Matteo Niccoli. R code by Kevin Wright.

### References

Matteo Niccoli (2010). Perceptually improved colormaps. http://www.mathworks.com/matlabcentral/fileexchange/28982-perceptually-improved-colormaps Color definitions from here: http://www.mathworks.com/matlabcentral/fileexchange/28982-perceptually-improved-colormaps/content/pmkmp/pmkmp.m https://mycarta.wordpress.com/2012/05/29/the-rainbow-is-dead-long-live-the-rainbow-series-outline/

### Examples

    pal.bands(cubicyf,cubicl,isol,linearl,linearlhot)
    pal.test(cubicyf) # purple blue green
    pal.test(cubicl) # purple blue green orange
    # pal.test(isol) # magenta blue green red. Poor in green area.
    # pal.test(linearl) # black blue green tan. Poor in black area.
    # pal.test(linearlhot) # black red yellow

[Package pals version 1.5 Index]