Chroma and hue angle from a* and b*

\(C^*_{ab} = \sqrt{a^{*2} + b^{*2}}\), \(h_{ab} = atan2(b^*, a^*)\) in degrees [0, 360). Melanized hyphae have low chroma; yellow/cream bacterial growth and diffusible pigments have hue angles near 70-100 deg.

lab_chroma_hue(a, b)

Arguments

a, b

Numeric vectors.

Value

A list with elements chroma and hue (degrees).

Examples

lab_chroma_hue(a = c(0, 5), b = c(0, 20))
#> $chroma
#> [1]  0.00000 20.61553
#> 
#> $hue
#> [1]  0.00000 75.96376
#>