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

Value

Numeric value of the maximum distance.

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.

References

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

Author

Kevin Wright

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
#> [1] 2.360173
pal.maxdist(pa0,pa2) # 5.20
#> [1] 5.204223
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)
#> [1] 101.6535