This function creates colors of class ``LAB''; a subclass of the virtual
LAB(L, A, B, names)
these arguments give the L, A and B coordinates of the colors.
The values can be provided in separate
vectors or in a three-column matrix passed as
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
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.