This function creates colors of class XYZ; a subclass of the virtual
color-class class.
Usage
XYZ(X, Y, Z, names)
Value
An object of class XYZ which inherits from class color.
Arguments
X, Y, Z
these arguments give the X, Y and Z coordinates of the colors.
The values can be provided in separate X, Y and Z
vectors or in a three-column matrix passed as X.
names
A vector of names for the colors (by default the row names of
X are used).
Author
Ross Ihaka
Details
The X, Y and Z values are the levels of the CIE primaries. These are scaled
so that the luminance of the display white-point is 100. The white-point is
taken to be D65, which means that its coordinates are 95.047, 100.000,
108.883.