colorSpec
colorSpec is an R package providing an S3 class with methods for color spectra. It supports the standard calculations with spectral properties of light sources, materials, cameras, eyes, scanners, etc. And it works well with the more general action spectra.
When a spectrum is contructed, a quantity is required,
though it can be changed after contruction.
The colorSpec quantities are typically not the same as the SI quantities;
they are more general.
There are 14 quantities, which then defined the 4 basic spectrum types,
as given in this table from the User Guide.
The quantity is used to label plots,
and to make sense out of the arguments in the function product().
The function invert() implements a method in