This function creates colors of class ``LAB''; a subclass of the virtual color-class class.

LAB(L, A, B, names)


L, A, B

these arguments give the L, A and B coordinates of the colors. The values can be provided in separate L, A and B vectors or in a three-column matrix passed as L.


a vector of names for the colors (by default the row names of L are used).


An object of class LAB which inherits from class color.


The L, A and B values give the coordinates of the colors in the CIE \(L^*a^*b^*\) space. This is a transformation of the 1931 CIE XYZ space which attempts to produce perceptually based axes. Luminance takes values between 0 and 100, and the other coordinates typically take values between -100 and 100, although these values can also be exceeded by highly saturated colors. The \(a\) and \(b\) coordinates measure positions on green/red and blue/yellow axes.

See also


Ross Ihaka


## Show the LAB space set.seed(1) x <- RGB(runif(1000), runif(1000), runif(1000)) y <- as(x, "LAB") head(x)
#> R G B #> [1,] 0.2655087 0.5308088 0.871805
#> L A B #> [1,] 76.00763 -4.987872 -28.84153