Round Up a double to int
Are you asking about System.Math.Ceiling? Math.Ceiling(0.2) == 1 Math.Ceiling(0.8) == 1 Math.Ceiling(2.6) == 3 Math.Ceiling(-1.4) == -1
approximation
Convert light frequency to RGB?
Here’s a detailed explanation of the entire conversion process: http://www.fourmilab.ch/documents/specrend/. Source code included!