R: Measure the maximum distance between two palettes

pal.maxdist {pals} | R Documentation

## Measure the maximum distance between two palettes

### Description

Measure the maximum distance between two palettes

### Usage

    pal.maxdist(pal1, pal2, n = 255)

### Arguments

`pal1` | A color palette (function or vector)
`pal2` | A color palette (function or vector)
`n` | Number of colors to use, default 255

### Details

The distance between two palettes (of equal length) is calculated pointwise using the Lab color space. A 'just noticeable difference' between colors is roughly 2.3.

### Value

Numeric value of the maximum distance.

### Author(s)

Kevin Wright

### References

https://en.wikipedia.org/wiki/Color_difference

### Examples

    pa0 <- c("#ff0000","#00ff00","#0000ff")
    pa1 <- c("#fa0000","#00fa00","#0000fa") # 2.4
    pa2 <- c("#f40000","#00f400","#0000f4") # 5.2
    pal.maxdist(pa0,pa1) # 2.36
    pal.maxdist(pa0,pa2) # 5.20
    pal.bands(pa1,pa0,pa2, labels=c("2.36","0","5.20"))
    title("Maximum Lab distance from middle palette")

    # distance between colormap functions
    pal.maxdist(coolwarm,warmcool)

[Package pals version 1.5 Index]